Tiwari, Swati; Tripathy, Baishnab Charan; Jajoo, Anjana; Das, Anath Bandhu; Murata, Norio; Sane, Prafullachandra Vishnu; Govindjee
2014-12-01
Prasanna K. Mohanty, a great scientist, a great teacher and above all a great human being, left us more than a year ago (on March 9, 2013). He was a pioneer in the field of photosynthesis research; his contributions are many and wide-ranging. In the words of Jack Myers, he would be a "photosynthetiker" par excellence. He remained deeply engaged with research almost to the end of his life; we believe that generations of researchers still to come will benefit from his thorough and enormous work. We present here his life and some of his contributions to the field of Photosynthesis Research. The response to this tribute was overwhelming and we have included most of the tributes, which we received from all over the world. Prasanna Mohanty was a pioneer in the field of "Light Regulation of Photosynthesis", a loving and dedicated teacher-unpretentious, idealistic, and an honest human being.
Mrs. Chandrasekhar poses with contest winners
NASA Technical Reports Server (NTRS)
1999-01-01
Mrs. Lalitha Chandrasekhar (left), wife of the late Indian- American Nobel Laureate Subrahmanyan Chandrasekhar, poses with a model of the Chandra X-ray Observatory and the winners of the contest to rename the telescope in the TRW Media Hospitality Tent at the NASA Press Site at KSC. The winners of the contest are Jatila van der Veen (center), academic coordinator and lecturer, Physics Dept., University of Santa Barbara, Calif., and Tyrel Johnson (right), high school student, Laclede, Idaho. The name 'Chandra,' a shortened version of Chandrasekhar's name which he preferred among friends and colleagues, was chosen to honor the Nobel Laureate. 'Chandra' also means 'Moon' or 'luminous' in Sanskrit. The observatory is scheduled to be launched aboard Columbia on Space Shuttle mission STS-93.
An effective algorithm for calculating the Chandrasekhar function
NASA Astrophysics Data System (ADS)
Jablonski, A.
2012-08-01
Numerical values of the Chandrasekhar function are needed with high accuracy in evaluations of theoretical models describing electron transport in condensed matter. An algorithm for such calculations should be possibly fast and also accurate, e.g. an accuracy of 10 decimal digits is needed for some applications. Two of the integral representations of the Chandrasekhar function are prospective for constructing such an algorithm, but suitable transformations are needed to obtain a rapidly converging quadrature. A mixed algorithm is proposed in which the Chandrasekhar function is calculated from two algorithms, depending on the value of one of the arguments. Catalogue identifier: AEMC_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEMC_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 567 No. of bytes in distributed program, including test data, etc.: 4444 Distribution format: tar.gz Programming language: Fortran 90 Computer: Any computer with a FORTRAN 90 compiler Operating system: Linux, Windows 7, Windows XP RAM: 0.6 Mb Classification: 2.4, 7.2 Nature of problem: An attempt has been made to develop a subroutine that calculates the Chandrasekhar function with high accuracy, of at least 10 decimal places. Simultaneously, this subroutine should be very fast. Both requirements stem from the theory of electron transport in condensed matter. Solution method: Two algorithms were developed, each based on a different integral representation of the Chandrasekhar function. The final algorithm is edited by mixing these two algorithms and by selecting ranges of the argument ω in which performance is the fastest. Restrictions: Two input parameters for the Chandrasekhar function, x and ω (notation used in the code), are restricted to the range: 0⩽x⩽1 and 0⩽ω⩽1
Mrs. Chandrasekhar poses with model of the Chandra X-ray Observatory
NASA Technical Reports Server (NTRS)
1999-01-01
Mrs. Lalitha Chandrasekhar, wife of the late Indian-American Nobel Laureate Subrahmanyan Chandrasekhar, poses with a model of the Chandra X-ray Observatory in the TRW Media Hospitality Tent at the NASA Press Site at KSC. The name 'Chandra,' a shortened version of Chandrasekhar's name which he preferred among friends and colleagues, was chosen in a contest to rename the telescope. 'Chandra' also means 'Moon' or 'luminous' in Sanskrit. The observatory is scheduled to be launched aboard Columbia on Space Shuttle mission STS-93.
Chandrasekhar Limit: An Elementary Approach Based on Classical Physics and Quantum Theory
ERIC Educational Resources Information Center
Pinochet, Jorge; Van Sint Jan, Michael
2016-01-01
In a brief article published in 1931, Subrahmanyan Chandrasekhar made public an important astronomical discovery. In his article, the then young Indian astrophysicist introduced what is now known as the "Chandrasekhar limit." This limit establishes the maximum mass of a stellar remnant beyond which the repulsion force between electrons…
Mrs. Chandrasekhar addresses the media in TRW Media Hospitality Tent
NASA Technical Reports Server (NTRS)
1999-01-01
Mrs. Lalitha Chandrasekhar (at podium), wife of the late Indian- American Nobel Laureate Subrahmanyan Chandrasekhar, addresses the media and other invited guests in the TRW Media Hospitality Tent at the NASA Press Site at KSC. Other participants in the program (seated facing the audience, left to right) are the winners of the contest to rename the telescope, Jatila van der Veen, academic coordinator and lecturer, Physics Dept., University of Santa Barbara, Calif., and Tyrel Johnson, high school student, Laclede, Idaho; Joanne Maguire, vice-president and general manager, TRW Space & Laser Programs Division; and Dr. Alan Bunner, Science Program Director, Structure and Evolution of the Universe, Office of Space Science, NASA Headquarters, Washington, D.C. The name 'Chandra,' a shortened version of Chandrasekhar, was the name the Nobel Laureate preferred among friends and colleagues. 'Chandra' also means 'Moon' or 'luminous' in Sanskrit. The observatory is scheduled to be launched aboard Columbia on Space Shuttle mission STS-93.
Chandrasekhar equations for infinite dimensional systems
NASA Technical Reports Server (NTRS)
Ito, K.; Powers, R.
1985-01-01
The existence of Chandrasekhar equations for linear time-invariant systems defined on Hilbert spaces is investigated. An important consequence is that the solution to the evolutional Riccati equation is strongly differentiable in time, and that a strong solution of the Riccati differential equation can be defined. A discussion of the linear-quadratic optimal-control problem for hereditary differential systems is also included.
Chandrasekhar equations for infinite dimensional systems. Part 2: Unbounded input and output case
NASA Technical Reports Server (NTRS)
Ito, Kazufumi; Powers, Robert K.
1987-01-01
A set of equations known as Chandrasekhar equations arising in the linear quadratic optimal control problem is considered. In this paper, we consider the linear time-invariant system defined in Hilbert spaces involving unbounded input and output operators. For a general class of such systems, the Chandrasekhar equations are derived and the existence, uniqueness, and regularity of the results of their solutions established.
Chandrasekhar equations for infinite dimensional systems
NASA Technical Reports Server (NTRS)
Ito, K.; Powers, R. K.
1985-01-01
Chandrasekhar equations are derived for linear time invariant systems defined on Hilbert spaces using a functional analytic technique. An important consequence of this is that the solution to the evolutional Riccati equation is strongly differentiable in time and one can define a strong solution of the Riccati differential equation. A detailed discussion on the linear quadratic optimal control problem for hereditary differential systems is also included.
Mrs. Chandrasekhar addresses the media in TRW Media Hospitality Tent
NASA Technical Reports Server (NTRS)
1999-01-01
Mrs. Lalitha Chandrasekhar (right), wife of the late Indian- American Nobel Laureate Subrahmanyan Chandrasekhar, addresses the media and other invited guests in the TRW Media Hospitality Tent at the NASA Press Site at KSC as Dr. Alan Bunner, Science Program Director, Structure and Evolution of the Universe, Office of Space Science, NASA Headquarters, Washington, D.C., looks on. The name 'Chandra,' a shortened version of her husband's name which he preferred among friends and colleagues, was chosen in a contest to rename the Advanced X-ray Astrophysics Facility. 'Chandra' also means 'Moon' or 'luminous' in Sanskrit. The observatory is scheduled to be launched aboard Columbia on Space Shuttle mission STS-93.
Chandrasekhar's dynamical friction and non-extensive statistics
DOE Office of Scientific and Technical Information (OSTI.GOV)
Silva, J.M.; Lima, J.A.S.; De Souza, R.E.
2016-05-01
The motion of a point like object of mass M passing through the background potential of massive collisionless particles ( m || M ) suffers a steady deceleration named dynamical friction. In his classical work, Chandrasekhar assumed a Maxwellian velocity distribution in the halo and neglected the self gravity of the wake induced by the gravitational focusing of the mass M . In this paper, by relaxing the validity of the Maxwellian distribution due to the presence of long range forces, we derive an analytical formula for the dynamical friction in the context of the q -nonextensive kinetic theory. Inmore » the extensive limiting case ( q = 1), the classical Gaussian Chandrasekhar result is recovered. As an application, the dynamical friction timescale for Globular Clusters spiraling to the galactic center is explicitly obtained. Our results suggest that the problem concerning the large timescale as derived by numerical N -body simulations or semi-analytical models can be understood as a departure from the standard extensive Maxwellian regime as measured by the Tsallis nonextensive q -parameter.« less
NASA Astrophysics Data System (ADS)
Das, Upasana; Mukhopadhyay, Banibrata
2015-05-01
We explore the effect of modification to Einstein's gravity in white dwarfs for the first time in the literature, to the best of our knowledge. This leads to significantly sub- and super-Chandrasekhar limiting masses of white dwarfs, determined by a single model parameter. On the other hand, type Ia supernovae (SNeIa), a key to unravel the evolutionary history of the universe, are believed to be triggered in white dwarfs having mass close to the Chandrasekhar limit. However, observations of several peculiar, under- and over-luminous SNeIa argue for exploding masses widely different from this limit. We argue that explosions of the modified gravity induced sub- and super-Chandrasekhar limiting mass white dwarfs result in under- and over-luminous SNeIa respectively, thus unifying these two apparently disjoint sub-classes and, hence, serving as a missing link. Our discovery raises two fundamental questions. Is the Chandrasekhar limit unique? Is Einstein's gravity the ultimate theory for understanding astronomical phenomena? Both the answers appear to be no!
Evidence for a Sub-Chandrasekhar-mass Type Ia Supernova in the Ursa Minor Dwarf Galaxy
NASA Astrophysics Data System (ADS)
McWilliam, Andrew; Piro, Anthony L.; Badenes, Carles; Bravo, Eduardo
2018-04-01
A long-standing problem is identifying the elusive progenitors of Type Ia supernovae (SNe Ia), which can roughly be split into Chandraksekhar and sub-Chandrasekhar-mass events. An important difference between these two cases is the nucleosynthetic yield, which is altered by the increased neutron excess in Chandrasekhar progenitors due to their pre-explosion simmering and high central density. Based on these arguments, we show that the chemical composition of the most metal-rich star in the Ursa Minor dwarf galaxy, COS 171, is dominated by nucleosynthesis from a low-metallicity, low-mass, sub-Chandrasekhar-mass SN Ia. Key diagnostic abundance ratios include Mn/Fe and Ni/Fe, which could not have been produced by a Chandrasekhar-mass SN Ia. Large deficiencies of Ni/Fe, Cu/Fe and Zn/Fe also suggest the absence of alpha-rich freeze-out nucleosynthesis, favoring low-mass white dwarf progenitors of SNe Ia, near 0.95 M ⊙, from comparisons to numerical detonation models. We also compare Mn/Fe and Ni/Fe ratios to the recent yields predicted by Shen et al., finding consistent results. To explain the [Fe/H] at ‑1.35 dex for COS 171 would require dilution of the SN Ia ejecta with ∼104 M ⊙ of material, which is expected for an SN remnant expanding into a warm interstellar medium with n ∼ 1 cm‑3. In the future, finding more stars with the unique chemical signatures we highlight here will be important for constraining the rate and environments of sub-Chandrasekhar SNe Ia.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Das, Upasana; Mukhopadhyay, Banibrata, E-mail: upasana@physics.iisc.ernet.in, E-mail: bm@physics.iisc.ernet.in
2015-05-01
We explore the effect of modification to Einstein's gravity in white dwarfs for the first time in the literature, to the best of our knowledge. This leads to significantly sub- and super-Chandrasekhar limiting masses of white dwarfs, determined by a single model parameter. On the other hand, type Ia supernovae (SNeIa), a key to unravel the evolutionary history of the universe, are believed to be triggered in white dwarfs having mass close to the Chandrasekhar limit. However, observations of several peculiar, under- and over-luminous SNeIa argue for exploding masses widely different from this limit. We argue that explosions of themore » modified gravity induced sub- and super-Chandrasekhar limiting mass white dwarfs result in under- and over-luminous SNeIa respectively, thus unifying these two apparently disjoint sub-classes and, hence, serving as a missing link. Our discovery raises two fundamental questions. Is the Chandrasekhar limit unique? Is Einstein's gravity the ultimate theory for understanding astronomical phenomena? Both the answers appear to be no!.« less
White dwarf stars exceeding the Chandrasekhar mass limit
NASA Astrophysics Data System (ADS)
Tomaschitz, Roman
2018-01-01
The effect of nonlinear ultra-relativistic electron dispersion on the mass-radius relation of high-mass white dwarfs is studied. The dispersion is described by a permeability tensor in the Dirac equation, generated by the ionized high-density stellar matter, which constitutes the neutralizing background of the nearly degenerate electron plasma. The electron dispersion results in a stable mass-radius relation for high-mass white dwarfs, in contrast to a mass limit in the case of vacuum permeabilities. In the ultra-relativistic regime, the dispersion relation is a power law whose amplitude and scaling exponent is inferred from mass and radius estimates of two high-mass white dwarfs, Sirius B and LHS 4033. Evidence for the existence of super-Chandrasekhar mass white dwarfs is provided by several Type Ia supernovae (e.g., SN 2013cv, SN 2003fg, SN 2007if and SN 2009dc), whose mass ejecta exceed the Chandrasekhar limit by up to a factor of two. The dispersive mass-radius relation is used to estimate the radii, central densities, Fermi temperatures, bulk and compression moduli and sound velocities of their white dwarf progenitors.
Chandrasekhar equations and computational algorithms for distributed parameter systems
NASA Technical Reports Server (NTRS)
Burns, J. A.; Ito, K.; Powers, R. K.
1984-01-01
The Chandrasekhar equations arising in optimal control problems for linear distributed parameter systems are considered. The equations are derived via approximation theory. This approach is used to obtain existence, uniqueness, and strong differentiability of the solutions and provides the basis for a convergent computation scheme for approximating feedback gain operators. A numerical example is presented to illustrate these ideas.
Sub-Chandrasekhar-mass White Dwarf Detonations Revisited
NASA Astrophysics Data System (ADS)
Shen, Ken J.; Kasen, Daniel; Miles, Broxton J.; Townsley, Dean M.
2018-02-01
The detonation of a sub-Chandrasekhar-mass white dwarf (WD) has emerged as one of the most promising Type Ia supernova (SN Ia) progenitor scenarios. Recent studies have suggested that the rapid transfer of a very small amount of helium from one WD to another is sufficient to ignite a helium shell detonation that subsequently triggers a carbon core detonation, yielding a “dynamically driven double-degenerate double-detonation” SN Ia. Because the helium shell that surrounds the core explosion is so minimal, this scenario approaches the limiting case of a bare C/O WD detonation. Motivated by discrepancies in previous literature and by a recent need for detailed nucleosynthetic data, we revisit simulations of naked C/O WD detonations in this paper. We disagree to some extent with the nucleosynthetic results of previous work on sub-Chandrasekhar-mass bare C/O WD detonations; for example, we find that a median-brightness SN Ia is produced by the detonation of a 1.0 {M}ȯ WD instead of a more massive and rarer 1.1 {M}ȯ WD. The neutron-rich nucleosynthesis in our simulations agrees broadly with some observational constraints, although tensions remain with others. There are also discrepancies related to the velocities of the outer ejecta and light curve shapes, but overall our synthetic light curves and spectra are roughly consistent with observations. We are hopeful that future multidimensional simulations will resolve these issues and further bolster the dynamically driven double-degenerate double-detonation scenario’s potential to explain most SNe Ia.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Das, Upasana; Mukhopadhyay, Banibrata, E-mail: upasana@physics.iisc.ernet.in, E-mail: bm@physics.iisc.ernet.in
The topic of magnetized super-Chandrasekhar white dwarfs is in the limelight, particularly in the last few years, since our proposal of their existence. By full-scale general relativistic magnetohydrodynamic (GRMHD) numerical analysis, we confirm in this work the existence of stable, highly magnetized, significantly super-Chandrasekhar white dwarfs with mass more than 3 solar mass. While a poloidal field geometry renders the white dwarfs oblate, a toroidal field makes them prolate retaining an overall quasi-spherical shape, as speculated in our earlier work. These white dwarfs are expected to serve as the progenitors of over-luminous type Ia supernovae.
Improved algorithm for calculating the Chandrasekhar function
NASA Astrophysics Data System (ADS)
Jablonski, A.
2013-02-01
Theoretical models of electron transport in condensed matter require an effective source of the Chandrasekhar H(x,omega) function. A code providing the H(x,omega) function has to be both accurate and very fast. The current revision of the code published earlier [A. Jablonski, Comput. Phys. Commun. 183 (2012) 1773] decreased the running time, averaged over different pairs of arguments x and omega, by a factor of more than 20. The decrease of the running time in the range of small values of the argument x, less than 0.05, is even more pronounced, reaching a factor of 30. The accuracy of the current code is not affected, and is typically better than 12 decimal places. New version program summaryProgram title: CHANDRAS_v2 Catalogue identifier: AEMC_v2_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEMC_v2_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC license, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 976 No. of bytes in distributed program, including test data, etc.: 11416 Distribution format: tar.gz Programming language: Fortran 90 Computer: Any computer with a Fortran 90 compiler Operating system: Windows 7, Windows XP, Unix/Linux RAM: 0.7 MB Classification: 2.4, 7.2 Catalogue identifier of previous version: AEMC_v1_0 Journal reference of previous version: Comput. Phys. Commun. 183 (2012) 1773 Does the new version supersede the old program: Yes Nature of problem: An attempt has been made to develop a subroutine that calculates the Chandrasekhar function with high accuracy, of at least 10 decimal places. Simultaneously, this subroutine should be very fast. Both requirements stem from the theory of electron transport in condensed matter. Solution method: Two algorithms were developed, each based on a different integral representation of the Chandrasekhar function. The final algorithm is edited by mixing these two
The type Ia supernova SNLS-03D3bb from a super-Chandrasekhar-masswhite dwarf star
DOE Office of Scientific and Technical Information (OSTI.GOV)
Howell, D.Andrew; Sullivan, Mark; Nugent, Peter E.
2006-02-01
The acceleration of the expansion of the universe, and theneed for Dark Energy, were inferred from the observations of Type Iasupernovae (SNe Ia) 1;2. There is consensus that SNeIa are thermonuclearexplosions that destroy carbon-oxygen white dwarf stars that accretematter from a companion star3, although the nature of this companionremains uncertain. SNe Ia are thought to be reliable distance indicatorsbecause they have a standard amount of fuel and a uniform trigger theyare predicted to explode when the mass of the white dwarf nears theChandrasekhar mass 4 - 1.4 solar masses. Here we show that the highredshift supernova SNLS-03D3bb has an exceptionallymore » high luminosity andlow kinetic energy that both imply a super-Chandrasekhar mass progenitor.Super-Chandrasekhar mass SNeIa shouldpreferentially occur in a youngstellar population, so this may provide an explanation for the observedtrend that overluminous SNe Ia only occur in young environments5;6. Sincethis supernova does not obey the relations that allow them to becalibrated as standard candles, and since no counterparts have been foundat low redshift, future cosmology studies will have to considercontamination from such events.« less
Highly magnetized super-Chandrasekhar white dwarfs and their consequences
NASA Astrophysics Data System (ADS)
Mukhopadhyay, B.; Das, U.; Rao, A. R.
2018-01-01
Since 2012, we have been exploring possible existence of highly magnetized significantly super-Chandrasekhar white dwarfs with a new mass-limit. This explains several observations, e.g. peculiar over-luminous type Ia supernovae, some white dwarf pulsars, soft gamma-ray repeaters and anomalous X-ray pulsars, which otherwise puzzled us enormously. We have proceeded to uncover the underlying issues by exploiting the enormous potential in quantum, classical and relativistic effects lying with magnetic fields present in white dwarfs. We have also explored the issues related to the stability and gravitational radiation of these white dwarfs.
The type Ia supernova SNLS-03D3bb from a super-Chandrasekhar-mass white dwarf star.
Howell, D Andrew; Sullivan, Mark; Nugent, Peter E; Ellis, Richard S; Conley, Alexander J; Le Borgne, Damien; Carlberg, Raymond G; Guy, Julien; Balam, David; Basa, Stephane; Fouchez, Dominique; Hook, Isobel M; Hsiao, Eric Y; Neill, James D; Pain, Reynald; Perrett, Kathryn M; Pritchet, Christopher J
2006-09-21
The accelerating expansion of the Universe, and the need for dark energy, were inferred from observations of type Ia supernovae. There is a consensus that type Ia supernovae are thermonuclear explosions that destroy carbon-oxygen white dwarf stars that have accreted matter from a companion star, although the nature of this companion remains uncertain. These supernovae are thought to be reliable distance indicators because they have a standard amount of fuel and a uniform trigger: they are predicted to explode when the mass of the white dwarf nears the Chandrasekhar mass of 1.4 solar masses (M(o)). Here we show that the high-redshift supernova SNLS-03D3bb has an exceptionally high luminosity and low kinetic energy that both imply a super-Chandrasekhar-mass progenitor. Super-Chandrasekhar-mass supernovae should occur preferentially in a young stellar population, so this may provide an explanation for the observed trend that overluminous type Ia supernovae occur only in 'young' environments. As this supernova does not obey the relations that allow type Ia supernovae to be calibrated as standard candles, and as no counterparts have been found at low redshift, future cosmology studies will have to consider possible contamination from such events.
Cao, Yi; Johansson, J.; Nugent, Peter E.; ...
2016-06-01
In this study, we report observations of a peculiar SN Ia iPTF13asv (a.k.a., SN2013cv) from the onset of the explosion to months after its peak. The early-phase spectra of iPTF13asv show an absence of iron absorption, indicating that synthesized iron elements are confined to low-velocity regions of the ejecta, which, in turn, implies a stratified ejecta structure along the line of sight. Our analysis of iPTF13asv's light curves and spectra shows that it is an intermediate case between normal and super-Chandrasekhar events. On the one hand, its light curve shape (B-bandmore » $${\\rm{\\Delta }}{m}_{15}=1.03\\pm 0.01$$) and overall spectral features resemble those of normal SNe Ia. On the other hand, its large peak optical and UV luminosity ($${M}_{B}=-19.84\\;{\\rm{mag}}$$, $${M}_{{uvm}2}=-15.5\\;{\\rm{mag}}$$) and its low but almost constant Si ii velocities of about 10,000 km s -1 are similar to those in super-Chandrasekhar events, and its persistent carbon signatures in the spectra are weaker than those seen commonly in super-Chandrasekhar events. We estimate a 56Ni mass of $${0.81}_{-0.18}^{+0.10}{M}_{\\odot }$$ and a total ejecta mass of $${1.59}_{-0.12}^{+0.45}{M}_{\\odot }$$. Finally, the large ejecta mass of iPTF13asv and its stratified ejecta structure together seemingly favor a double-degenerate origin.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Hillman, Y.; Prialnik, D.; Kovetz, A.
Can a white dwarf (WD), accreting hydrogen-rich matter from a non-degenerate companion star, ever exceed the Chandrasekhar mass and explode as a SN Ia? We explore the range of accretion rates that allow a WD to secularly grow in mass, and derive limits on the accretion rate and on the initial mass that will allow it to reach 1.4M{sub ⊙}—the Chandrasekhar mass. We follow the evolution through a long series of hydrogen flashes, during which a thick helium shell accumulates. This determines the effective helium mass accretion rate for long-term, self-consistent evolutionary runs with helium flashes. We find that netmore » mass accumulation always occurs despite helium flashes. Although the amount of mass lost during the first few helium shell flashes is a significant fraction of that accumulated prior to the flash, that fraction decreases with repeated helium shell flashes. Eventually no mass is ejected at all during subsequent flashes. This unexpected result occurs because of continual heating of the WD interior by the helium shell flashes near its surface. The effect of heating is to lower the electron degeneracy throughout the WD, especially in the outer layers. This key result yields helium burning that is quasi-steady state, instead of explosive. We thus find a remarkably large parameter space within which long-term, self-consistent simulations show that a WD can grow in mass and reach the Chandrasekhar limit, despite its helium flashes.« less
The double-degenerate, super-Chandrasekhar nucleus of the planetary nebula Henize 2-428.
Santander-García, M; Rodríguez-Gil, P; Corradi, R L M; Jones, D; Miszalski, B; Boffin, H M J; Rubio-Díez, M M; Kotze, M M
2015-03-05
The planetary nebula stage is the ultimate fate of stars with masses one to eight times that of the Sun (M(⊙)). The origin of their complex morphologies is poorly understood, although several mechanisms involving binary interaction have been proposed. In close binary systems, the orbital separation is short enough for the primary star to overfill its Roche lobe as the star expands during the asymptotic giant branch phase. The excess gas eventually forms a common envelope surrounding both stars. Drag forces then result in the envelope being ejected into a bipolar planetary nebula whose equator is coincident with the orbital plane of the system. Systems in which both stars have ejected their envelopes and are evolving towards the white dwarf stage are said to be double degenerate. Here we report that Henize 2-428 has a double-degenerate core with a combined mass of ∼1.76M(⊙), which is above the Chandrasekhar limit (the maximum mass of a stable white dwarf) of 1.4M(⊙). This, together with its short orbital period (4.2 hours), suggests that the system should merge in 700 million years, triggering a type Ia supernova event. This supports the hypothesis of the double-degenerate, super-Chandrasekhar evolutionary pathway for the formation of type Ia supernovae.
Yamaguchi, Hiroya; Badenes, Carles; Foster, Adam R.; ...
2015-03-12
Despite decades of intense efforts, many fundamental aspects of Type Ia supernovae (SNe Ia) remain elusive. One of the major open questions is whether the mass of an exploding white dwarf (WD) is close to the Chandrasekhar limit. Here, we report the detection of strong K-shell emission from stable Fe-peak elements in the Suzaku X-ray spectrum of the Type Ia supernova remnant (SNR) 3C 397. The high Ni/Fe and Mn/Fe mass ratios (0.11–0.24 and 0.018–0.033, respectively) in the hot plasma component that dominates the K-shell emission lines indicate a degree of neutronization in the supernova ejecta that can only bemore » achieved by electron capture in the dense cores of exploding WDs with a near-Chandrasekhar mass. This suggests a single-degenerate origin for 3C 397, since Chandrasekhar mass progenitors are expected naturally if the WD accretes mass slowly from a companion. Altogether with other results supporting the double-degenerate scenario, our work adds to the mounting evidence that both progenitor channels make a significant contribution to the SN Ia rate in star-forming galaxies.« less
NASA Technical Reports Server (NTRS)
Yamaguchi, Hiroya; Badenes, Carles; Foster, Adam R.; Bravo, Eduardo; Williams, Brian J.; Maeda, Keiichi; Nobukawa, Masayoshi; Eriksen, Kristoffer A.; Brickhouse, Nancy S.; Petre, Robert;
2015-01-01
Despite decades of intense efforts, many fundamental aspects of Type Ia supernovae (SNe Ia) remain elusive. One of the major open questions is whether the mass of an exploding white dwarf (WD) is close to the Chandrasekhar limit. Here, we report the detection of strong K-shell emission from stable Fe-peak elements in the Suzaku X-ray spectrum of the Type Ia supernova remnant (SNR) 3C 397. The high Ni/Fe and Mn/Fe mass ratios - (0.11-0.24 and 0.018-0.033, respectively) in the hot plasma component that dominates the K-shell emission lines indicate a degree of neutronization in the supernova ejecta that can only be achieved by electron capture in the dense cores of exploding WDs with a near-Chandrasekhar mass. This suggests a single-degenerate origin for 3C 397, since Chandrasekhar mass progenitors are expected naturally if the WD accretes mass slowly from a companion. Together with other results supporting the double-degenerate scenario, our work adds to the mounting evidence that both progenitor channels make a significant contribution to the SN Ia rate in star-forming galaxies.
Double-detonation Sub-Chandrasekhar Supernovae: Synthetic Observables for Minimum Helium Shell Mass Models
NASA Astrophysics Data System (ADS)
Kromer, M.; Sim, S. A.; Fink, M.; Röpke, F. K.; Seitenzahl, I. R.; Hillebrandt, W.
2010-08-01
In the double-detonation scenario for Type Ia supernovae, it is suggested that a detonation initiates in a shell of helium-rich material accreted from a companion star by a sub-Chandrasekhar-mass white dwarf. This shell detonation drives a shock front into the carbon-oxygen white dwarf that triggers a secondary detonation in the core. The core detonation results in a complete disruption of the white dwarf. Earlier studies concluded that this scenario has difficulties in accounting for the observed properties of Type Ia supernovae since the explosion ejecta are surrounded by the products of explosive helium burning in the shell. Recently, however, it was proposed that detonations might be possible for much less massive helium shells than previously assumed (Bildsten et al.). Moreover, it was shown that even detonations of these minimum helium shell masses robustly trigger detonations of the carbon-oxygen core (Fink et al.). Therefore, it is possible that the impact of the helium layer on observables is less than previously thought. Here, we present time-dependent multi-wavelength radiative transfer calculations for models with minimum helium shell mass and derive synthetic observables for both the optical and γ-ray spectral regions. These differ strongly from those found in earlier simulations of sub-Chandrasekhar-mass explosions in which more massive helium shells were considered. Our models predict light curves that cover both the range of brightnesses and the rise and decline times of observed Type Ia supernovae. However, their colors and spectra do not match the observations. In particular, their B - V colors are generally too red. We show that this discrepancy is mainly due to the composition of the burning products of the helium shell of the Fink et al. models which contain significant amounts of titanium and chromium. Using a toy model, we also show that the burning products of the helium shell depend crucially on its initial composition. This leads us to
Frequency band of the f-mode Chandrasekhar-Friedman-Schutz instability
DOE Office of Scientific and Technical Information (OSTI.GOV)
Zink, Burkhard; Korobkin, Oleg; Schnetter, Erik
2010-04-15
Rapidly rotating neutron stars can be unstable to the gravitational-wave-driven Chandrasekhar-Friedman-Schutz (CFS) mechanism if they have a neutral point in the spectrum of nonaxisymmetric f-modes. We investigate the frequencies of these modes in two sequences of uniformly rotating polytropes using nonlinear simulations in full general relativity, determine the approximate locations of the neutral points, and derive limits on the observable frequency band available to the instability in these sequences. We find that general relativity enhances the detectability of a CFS-unstable neutron star substantially, both by widening the instability window and enlarging the band into the optimal range for interferometric detectorsmore » like LIGO, VIRGO, and GEO-600.« less
NASA Technical Reports Server (NTRS)
Choudhury, A. K.; Djalali, M.
1975-01-01
In this recursive method proposed, the gain matrix for the Kalman filter and the convariance of the state vector are computed not via the Riccati equation, but from certain other equations. These differential equations are of Chandrasekhar-type. The 'invariant imbedding' idea resulted in the reduction of the basic boundary value problem of transport theory to an equivalent initial value system, a significant computational advance. Initial value experience showed that there is some computational savings in the method and the loss of positive definiteness of the covariance matrix is less vulnerable.
NASA Astrophysics Data System (ADS)
Goldstein, Daniel A.; Kasen, Daniel
2018-01-01
There are two classes of viable progenitors for normal Type Ia supernovae (SNe Ia): systems in which a white dwarf explodes at the Chandrasekhar mass ({M}{ch}), and systems in which a white dwarf explodes below the Chandrasekhar mass (sub-{M}{ch}). It is not clear which of these channels is dominant; observations and light-curve modeling have provided evidence for both. Here we use an extensive grid of 4500 time-dependent, multiwavelength radiation transport simulations to show that the sub-{M}{ch} model can reproduce the entirety of the width–luminosity relation, while the {M}{ch} model can only produce the brighter events (0.8< {{Δ }}{M}15(B)< 1.55), implying that fast-declining SNe Ia come from sub-{M}{ch} explosions. We do not assume a particular theoretical paradigm for the progenitor or explosion mechanism, but instead construct parameterized models that vary the mass, kinetic energy, and compositional structure of the ejecta, thereby realizing a broad range of possible outcomes of white dwarf explosions. We provide fitting functions based on our large grid of detailed simulations that map observable properties of SNe Ia, such as peak brightness and light-curve width, to physical parameters such as {}56{Ni} and total ejected mass. These can be used to estimate the physical properties of observed SNe Ia.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Balakin, A. B.; Zayats, A. E.; Sushkov, S. V.
2007-04-15
We discuss exact solutions of a three-parameter nonminimal Einstein-Yang-Mills model, which describe the wormholes of a new type. These wormholes are considered to be supported by the SU(2)-symmetric Yang-Mills field, nonminimally coupled to gravity, the Wu-Yang ansatz for the gauge field being used. We distinguish between regular solutions, describing traversable nonminimal Wu-Yang wormholes, and black wormholes possessing one or two event horizons. The relation between the asymptotic mass of the regular traversable Wu-Yang wormhole and its throat radius is analyzed.
NASA Astrophysics Data System (ADS)
Becerra, L.; Rueda, J. A.; Lorén-Aguilar, P.; García-Berro, E.
2018-04-01
The evolution of the remnant of the merger of two white dwarfs is still an open problem. Furthermore, few studies have addressed the case in which the remnant is a magnetic white dwarf with a mass larger than the Chandrasekhar limiting mass. Angular momentum losses might bring the remnant of the merger to the physical conditions suitable for developing a thermonuclear explosion. Alternatively, the remnant may be prone to gravitational or rotational instabilities, depending on the initial conditions reached after the coalescence. Dipole magnetic braking is one of the mechanisms that can drive such losses of angular momentum. However, the timescale on which these losses occur depends on several parameters, like the strength of the magnetic field. In addition, the coalescence leaves a surrounding Keplerian disk that can be accreted by the newly formed white dwarf. Here we compute the post-merger evolution of a super-Chandrasekhar magnetized white dwarf taking into account all the relevant physical processes. These include magnetic torques acting on the star, accretion from the Keplerian disk, the threading of the magnetic field lines through the disk, and the thermal evolution of the white dwarf core. We find that the central remnant can reach the conditions suitable to develop a thermonuclear explosion before other instabilities (such as the inverse beta-decay instability or the secular axisymmetric instability) are reached, which would instead lead to gravitational collapse of the magnetized remnant.
Duality Quantum Simulation of the Yang-Baxter Equation
NASA Astrophysics Data System (ADS)
Zheng, Chao; Wei, Shijie
2018-04-01
The Yang-Baxter equation has become a significant theoretical tool in a variety of areas of physics. It is desirable to investigate the quantum simulation of the Yang-Baxter equation itself, exploring the connections between quantum integrability and quantum information processing, in which the unity of both the Yang-Baxter equation system and its quantum entanglement should be kept as a whole. In this work, we propose a duality quantum simulation algorithm of the Yang-Baxter equation, which contains the Yang-Baxter system and an ancillary qubit. Contrasting to conventional methods in which the two hand sides of the equation are simulated separately, they are simulated simultaneously in this proposal. Consequently, it opens up a way to further investigate entanglements in a Yang-Baxter equation.
Duality Quantum Simulation of the Yang-Baxter Equation
NASA Astrophysics Data System (ADS)
Zheng, Chao; Wei, Shijie
2018-07-01
The Yang-Baxter equation has become a significant theoretical tool in a variety of areas of physics. It is desirable to investigate the quantum simulation of the Yang-Baxter equation itself, exploring the connections between quantum integrability and quantum information processing, in which the unity of both the Yang-Baxter equation system and its quantum entanglement should be kept as a whole. In this work, we propose a duality quantum simulation algorithm of the Yang-Baxter equation, which contains the Yang-Baxter system and an ancillary qubit. Contrasting to conventional methods in which the two hand sides of the equation are simulated separately, they are simulated simultaneously in this proposal. Consequently, it opens up a way to further investigate entanglements in a Yang-Baxter equation.
Loop quantum corrected Einstein Yang-Mills black holes
NASA Astrophysics Data System (ADS)
Protter, Mason; DeBenedictis, Andrew
2018-05-01
In this paper, we study the homogeneous interiors of black holes possessing SU(2) Yang-Mills fields subject to corrections inspired by loop quantum gravity. The systems studied possess both magnetic and induced electric Yang-Mills fields. We consider the system of equations both with and without Wilson loop corrections to the Yang-Mills potential. The structure of the Yang-Mills Hamiltonian, along with the restriction to homogeneity, allows for an anomaly-free effective quantization. In particular, we study the bounce which replaces the classical singularity and the behavior of the Yang-Mills fields in the quantum corrected interior, which possesses topology R ×S2 . Beyond the bounce, the magnitude of the Yang-Mills electric field asymptotically grows monotonically. This results in an ever-expanding R sector even though the two-sphere volume is asymptotically constant. The results are similar with and without Wilson loop corrections on the Yang-Mills potential.
Experimental Determination of Dynamical Lee-Yang Zeros
NASA Astrophysics Data System (ADS)
Brandner, Kay; Maisi, Ville F.; Pekola, Jukka P.; Garrahan, Juan P.; Flindt, Christian
2017-05-01
Statistical physics provides the concepts and methods to explain the phase behavior of interacting many-body systems. Investigations of Lee-Yang zeros—complex singularities of the free energy in systems of finite size—have led to a unified understanding of equilibrium phase transitions. The ideas of Lee and Yang, however, are not restricted to equilibrium phenomena. Recently, Lee-Yang zeros have been used to characterize nonequilibrium processes such as dynamical phase transitions in quantum systems after a quench or dynamic order-disorder transitions in glasses. Here, we experimentally realize a scheme for determining Lee-Yang zeros in such nonequilibrium settings. We extract the dynamical Lee-Yang zeros of a stochastic process involving Andreev tunneling between a normal-state island and two superconducting leads from measurements of the dynamical activity along a trajectory. From the short-time behavior of the Lee-Yang zeros, we predict the large-deviation statistics of the activity which is typically difficult to measure. Our method paves the way for further experiments on the statistical mechanics of many-body systems out of equilibrium.
NASA Astrophysics Data System (ADS)
Blondin, Stéphane; Dessart, Luc; Hillier, D. John; Khokhlov, Alexei M.
2017-09-01
The faster light-curve evolution of low-luminosity Type Ia supernovae (SNe Ia) suggests that they could result from the explosion of white dwarf (WD) progenitors below the Chandrasekhar mass (MCh). Here we present 1D non-local thermodynamic equilibrium time-dependent radiative transfer simulations of pure central detonations of carbon-oxygen WDs with a mass (Mtot) between 0.88 and 1.15 M⊙ and a 56Ni yield between 0.08 and 0.84 M⊙. Their lower ejecta density compared to MCh models results in a more rapid increase of the luminosity at early times and an enhanced γ-ray escape fraction past maximum light. Consequently, their bolometric light curves display shorter rise times and larger post-maximum decline rates. Moreover, the higher M(56Ni)/Mtot ratio at a given 56Ni mass enhances the temperature and ionization level in the spectrum-formation region for the less luminous models, giving rise to bluer colours at maximum light and a faster post-maximum evolution of the B - V colour. For sub-MCh models fainter than MB ≈ -18.5 mag at peak, the greater bolometric decline and faster colour evolution lead to a larger B-band post-maximum decline rate, ΔM15(B). In particular, all of our previously published MCh models (standard and pulsational delayed detonations) are confined to ΔM15(B) < 1.4 mag, while the sub-MCh models with Mtot ≲ 1 M⊙ extend beyond this limit to ΔM15(B) ≈ 1.65 mag for a peak MB ≈ -17 mag, in better agreement with the observed width-luminosity relation (WLR). Regardless of the precise ignition mechanism, these simulations suggest that fast-declining SNe Ia at the faint end of the WLR could result from the explosion of WDs whose mass is significantly below the Chandrasekhar limit.
Soluble Model Fluids with Complete Scaling and Yang-Yang Features
NASA Astrophysics Data System (ADS)
Cerdeiriña, Claudio A.; Orkoulas, Gerassimos; Fisher, Michael E.
2016-01-01
Yang-Yang (YY) and singular diameter critical anomalies arise in exactly soluble compressible cell gas (CCG) models that obey complete scaling with pressure mixing. Thus, on the critical isochore ρ =ρc , C˜ μ≔-T d2μ /d T2 diverges as |t |-α when t ∝T -Tc→0- while ρd-ρc˜|t |2β where ρd(T )=1/2 [ρliq+ρgas] . When the discrete local CCG cell volumes fluctuate freely, the YY ratio Rμ=C˜μ/CV may take any value -∞
DOE Office of Scientific and Technical Information (OSTI.GOV)
Argyros, I.K.
1984-01-01
In this dissertation perturbation techniques are developed, based on the contraction mapping principle which can be used to prove existence and uniqueness for the quadratic equation x = y + lambdaB(x,x) (1) in a Banach space X; here B: XxX..-->..X is a bounded, symmetric bilinear operator, lambda is a positive parameter and y as a subset of X is fixed. The following is the main result. Theorem. Suppose F: XxX..-->..X is a bounded, symmetric bilinear operator and that the equation z = y + lambdaF(z,z) has a solution z/sup */ of sufficiently small norm. Then equation (1) has a uniquemore » solution in a certain closed ball centered at z/sup */. Applications. The theorem is applied to the famous Chandrasekhar equation and to the Anselone-Moore system which are of the form (1) above and yields existence and uniqueness for a solution of (1) for larger values of lambda than previously known, as well as more accurate information on the location of solutions.« less
Quantum groups, Yang-Baxter maps and quasi-determinants
NASA Astrophysics Data System (ADS)
Tsuboi, Zengo
2018-01-01
For any quasi-triangular Hopf algebra, there exists the universal R-matrix, which satisfies the Yang-Baxter equation. It is known that the adjoint action of the universal R-matrix on the elements of the tensor square of the algebra constitutes a quantum Yang-Baxter map, which satisfies the set-theoretic Yang-Baxter equation. The map has a zero curvature representation among L-operators defined as images of the universal R-matrix. We find that the zero curvature representation can be solved by the Gauss decomposition of a product of L-operators. Thereby obtained a quasi-determinant expression of the quantum Yang-Baxter map associated with the quantum algebra Uq (gl (n)). Moreover, the map is identified with products of quasi-Plücker coordinates over a matrix composed of the L-operators. We also consider the quasi-classical limit, where the underlying quantum algebra reduces to a Poisson algebra. The quasi-determinant expression of the quantum Yang-Baxter map reduces to ratios of determinants, which give a new expression of a classical Yang-Baxter map.
Computing Critical Properties with Yang-Yang Anomalies
NASA Astrophysics Data System (ADS)
Orkoulas, Gerassimos; Cerdeirina, Claudio; Fisher, Michael
2017-01-01
Computation of the thermodynamics of fluids in the critical region is a challenging task owing to divergence of the correlation length and lack of particle-hole symmetries found in Ising or lattice-gas models. In addition, analysis of experiments and simulations reveals a Yang-Yang (YY) anomaly which entails sharing of the specific heat singularity between the pressure and the chemical potential. The size of the YY anomaly is measured by the YY ratio Rμ =C μ /CV of the amplitudes of C μ = - T d2 μ /dT2 and of the total specific heat CV. A ``complete scaling'' theory, in which the pressure mixes into the scaling fields, accounts for the YY anomaly. In Phys. Rev. Lett. 116, 040601 (2016), compressible cell gas (CCG) models which exhibit YY and singular diameter anomalies, have been advanced for near-critical fluids. In such models, the individual cell volumes are allowed to fluctuate. The thermodynamics of CCGs can be computed through mapping onto the Ising model via the seldom-used great grand canonical ensemble. The computations indicate that local free volume fluctuations are the origins of the YY effects. Furthermore, local energy-volume coupling (to model water) is another crucial factor underlying the phenomena.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Balakin, A. B.; Zayats, A. E.; Dehnen, H.
2007-12-15
We discuss a nonminimal Einstein-Yang-Mills-Higgs model with uniaxial anisotropy in the group space associated with the Higgs field. We apply this theory to the problem of propagation of color and color-acoustic waves in the gravitational background related to the nonminimal regular Wu-Yang monopole.
Relativistic collisions as Yang-Baxter maps
NASA Astrophysics Data System (ADS)
Kouloukas, Theodoros E.
2017-10-01
We prove that one-dimensional elastic relativistic collisions satisfy the set-theoretical Yang-Baxter equation. The corresponding collision maps are symplectic and admit a Lax representation. Furthermore, they can be considered as reductions of a higher dimensional integrable Yang-Baxter map on an invariant manifold. In this framework, we study the integrability of transfer maps that represent particular periodic sequences of collisions.
[Talk about nomenclature of twelve meridians from quantitative yin-yang theory].
Zhao, Xi-xin; Wang, Xue-xia; Zhao, Zhao; Ran, Peng-fei; Lü, Xiao-rui
2009-03-01
Based on leads provided by Neijing and other literature, analyze origins of the three-yin and the three-yang and the their respective contents of yin and yang, indicating the principle that the order of yang-qi from more to less is Yang ming, Tai yang, Shao yang, and the order of yin-qi is Tai yin, Shao yin, Jue yin. According to the location of five (six) zang-organs, respective yin-qi content is defined, and according to the principle of more yin-qi matches more, and less yin-qi matches less, five (six) zang-organs match each other. The zang-organs above the diaphragm joints with The Hand-Channels and the zang-organs below the diaphragm with The Foot-Channels, completing the nomenclature of twelve meridians. The names of the six yang-channels correspond to the yin-channels of the exterior-interior relationship, the yin-channels link with hands (feet), and the yang-channels also link with hands (feet), and the amount of yin-qi of the zang-organs corresponding to the yin-channels and the amount of yang-qi of the fu-organs corresponding to yang-channels are in a state of balance. Based on this principle, nomenclature of six channels are completed. Emphasize that the nomenclature of twelve meridians contains profound TCM theories, especially, TCM, by yin-yang, three-yin and three- yang, illustrates living phenomena from the whole to the system and organ level in human body, and the scientific principle "yin-yang can be unlimitedly divided" and its significance, which must guide the studies on living phenomena with modern life sciences from the whole to the molecular level.
NASA Astrophysics Data System (ADS)
Blondin, Stéphane; Dessart, Luc; Hillier, D. John
2018-03-01
While Chandrasekhar-mass (MCh) models with a low 56Ni yield can match the peak luminosities of fast-declining, 91bg-like Type Ia supernovae (SNe Ia), they systematically fail to reproduce their faster light-curve evolution. Here, we illustrate the impact of a low ejecta mass on the radiative display of low-luminosity SNe Ia, by comparing a sub-MCh model resulting from the pure central detonation of a C-O white dwarf (WD) to an MCh delayed-detonation model with the same 56Ni yield of 0.12 M⊙. Our sub-MCh model from a 0.90 M⊙ WD progenitor has a ˜5 d shorter rise time in the integrated UV-optical-IR (uvoir) luminosity, as well as in the B band, and a ˜20 per cent higher peak uvoir luminosity (˜1 mag brighter peak MB). This sub-MCh model also displays bluer maximum-light colours due to the larger specific heating rate, and larger post-maximum uvoir and B-band decline rates. The luminosity decline at nebular times is also more pronounced, reflecting the enhanced escape of gamma rays resulting from the lower density of the progenitor WD. The deficit of stable nickel in the innermost ejecta leads to a notable absence of forbidden lines of [Ni II] in the nebular spectra. In contrast, the MCh model displays a strong line due to [Ni II] 1.939 μm, which could in principle serve to distinguish between different progenitor scenarios. Our sub-MCh model offers an unprecedented agreement with optical and near-infrared observations of the 91bg-like SN 1999by, making a strong case for a WD progenitor significantly below the Chandrasekhar-mass limit for this event and other low-luminosity SNe Ia.
Two-spectral Yang-Baxter operators in topological quantum computation
NASA Astrophysics Data System (ADS)
Sanchez, William F.
2011-05-01
One of the current trends in quantum computing is the application of algebraic topological methods in the design of new algorithms and quantum computers, giving rise to topological quantum computing. One of the tools used in it is the Yang-Baxter equation whose solutions are interpreted as universal quantum gates. Lately, more general Yang-Baxter equations have been investigated, making progress as two-spectral equations and Yang-Baxter systems. This paper intends to apply these new findings to the field of topological quantum computation, more specifically, the proposition of the two-spectral Yang-Baxter operators as universal quantum gates for 2 qubits and 2 qutrits systems, obtaining 4x4 and 9x9 matrices respectively, and further elaboration of the corresponding Hamiltonian by the use of computer algebra software Mathematica® and its Qucalc package. In addition, possible physical systems to which the Yang-Baxter operators obtained can be applied are considered. In the present work it is demonstrated the utility of the Yang-Baxter equation to generate universal quantum gates and the power of computer algebra to design them; it is expected that these mathematical studies contribute to the further development of quantum computers
NASA Astrophysics Data System (ADS)
Kawabata, Kiyoshi
2016-12-01
This work shows that it is possible to calculate numerical values of the Chandrasekhar H-function for isotropic scattering at least with 15-digit accuracy by making use of the double exponential formula (DE-formula) of Takahashi and Mori (Publ. RIMS, Kyoto Univ. 9:721, 1974) instead of the Gauss-Legendre quadrature employed in the numerical scheme of Kawabata and Limaye (Astrophys. Space Sci. 332:365, 2011) and simultaneously taking a precautionary measure to minimize the effects due to loss of significant digits particularly in the cases of near-conservative scattering and/or errors involved in returned values of library functions supplied by compilers in use. The results of our calculations are presented for 18 selected values of single scattering albedo π0 and 22 values of an angular variable μ, the cosine of zenith angle θ specifying the direction of radiation incident on or emergent from semi-infinite media.
APC Yin-Yang haplotype associated with colorectal cancer risk
GARRE, P.; DE LA HOYA, M.; INIESTA, P.; ROMERA, A.; LLOVET, P.; GONZALEZ, S.; PEREZ-SEGURA, P.; CAPELLA, G.; DIAZ-RUBIO, E.; CALDES, T.
2010-01-01
The Yin-Yang haplotype is defined as two mismatched haplotypes (Yin and Yang) representing the majority of the existing haplotypes in a particular genomic region. The human adenomatous polyposis coli (APC) gene shows a Yin-Yang haplotype pattern accounting for 84% of all of the haplotypes existing in the Spanish population. Several association studies have been published regarding APC gene variants (SNPs and haplotypes) and colorectal cancer (CRC) risk. However, no studies concerning diplotype structure and CRC risk have been conducted. The aim of the present study was to investigate whether the APC Yin-Yang homozygote diplotype is over-represented in patients with sporadic CRC when compared to its distribution in controls, and its association with CRC risk. TaqMan® assays were used to genotype three tagSNPs selected across the APC Yin-Yang region. Frequencies of the APC Yin-Yang tagSNP alleles, haplotype and diplotype of 378 CRC cases and 642 controls were compared. Two Spanish CRC group samples were included [Hospital Clínico San Carlos in Madrid (HCSC) and Instituto Catalán de Oncología in Barcelona (ICO)]. Analysis of 157 consecutive CRC patients and 405 control subjects from HCSC showed a significative effect for the risk of CRC (OR=1.93; 95% CI 1.32–2.81; P=0.001). However, this effect was not confirmed in 221 CRC patients and 237 control subjects from ICO (OR=0.89; 95% CI 0.61–1.28; P=0.521). We found a significant association between the APC homozygote Yin-Yang diplotype and the risk of colorectal cancer in the HCSC samples. However, we did not observe this association in the ICO samples. These observations suggest that a study with a larger Spanish cohort is necessary to confirm the effects of the APC Yin-Yang diplotype on the risk of CRC. PMID:22993613
APC Yin-Yang haplotype associated with colorectal cancer risk.
Garre, P; DE LA Hoya, M; Iniesta, P; Romera, A; Llovet, P; Gonzalez, S; Perez-Segura, P; Capella, G; Diaz-Rubio, E; Caldes, T
2010-09-01
The Yin-Yang haplotype is defined as two mismatched haplotypes (Yin and Yang) representing the majority of the existing haplotypes in a particular genomic region. The human adenomatous polyposis coli (APC) gene shows a Yin-Yang haplotype pattern accounting for 84% of all of the haplotypes existing in the Spanish population. Several association studies have been published regarding APC gene variants (SNPs and haplotypes) and colorectal cancer (CRC) risk. However, no studies concerning diplotype structure and CRC risk have been conducted. The aim of the present study was to investigate whether the APC Yin-Yang homozygote diplotype is over-represented in patients with sporadic CRC when compared to its distribution in controls, and its association with CRC risk. TaqMan(®) assays were used to genotype three tagSNPs selected across the APC Yin-Yang region. Frequencies of the APC Yin-Yang tagSNP alleles, haplotype and diplotype of 378 CRC cases and 642 controls were compared. Two Spanish CRC group samples were included [Hospital Clínico San Carlos in Madrid (HCSC) and Instituto Catalán de Oncología in Barcelona (ICO)]. Analysis of 157 consecutive CRC patients and 405 control subjects from HCSC showed a significative effect for the risk of CRC (OR=1.93; 95% CI 1.32-2.81; P=0.001). However, this effect was not confirmed in 221 CRC patients and 237 control subjects from ICO (OR=0.89; 95% CI 0.61-1.28; P=0.521). We found a significant association between the APC homozygote Yin-Yang diplotype and the risk of colorectal cancer in the HCSC samples. However, we did not observe this association in the ICO samples. These observations suggest that a study with a larger Spanish cohort is necessary to confirm the effects of the APC Yin-Yang diplotype on the risk of CRC.
Holography and noncommutative yang-mills theory
Li; Wu
2000-03-06
In this Letter a recently proposed gravity dual of noncommutative Yang-Mills theory is derived from the relations between closed string moduli and open string moduli recently suggested by Seiberg and Witten. The only new input one needs is a simple form of the running string tension as a function of energy. This derivation provides convincing evidence that string theory integrates with the holographical principle and demonstrates a direct link between noncommutative Yang-Mills theory and holography.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Jacobs, A. M.; Zingale, M.; Nonaka, A.
2016-08-10
The dynamics of helium shell convection driven by nuclear burning establish the conditions for runaway in the sub-Chandrasekhar-mass, double-detonation model for SNe Ia, as well as for a variety of other explosive phenomena. We explore these convection dynamics for a range of white dwarf core and helium shell masses in three dimensions using the low Mach number hydrodynamics code MAESTRO. We present calculations of the bulk properties of this evolution, including time-series evolution of global diagnostics, lateral averages of the 3D state, and the global 3D state. We find a variety of outcomes, including quasi-equilibrium, localized runaway, and convective runaway.more » Our results suggest that the double-detonation progenitor model is promising and that 3D dynamic convection plays a key role.« less
Radiative double copy for Einstein-Yang-Mills theory
NASA Astrophysics Data System (ADS)
Chester, David
2018-04-01
Recently, a double-copy formalism was used to calculate gravitational radiation from classical Yang-Mills radiation solutions. This work shows that the Yang-Mills theory coupled to a biadjoint scalar field admits a radiative double copy that agrees with solutions in the Einstein-Yang-Mills theory at the lowest finite order. Within this context, the trace-reversed metric h¯μ ν is a natural double copy of the gauge boson Aμ a . This work provides additional evidence that solutions in gauge and gravity theories are related, even though their respective Lagrangians and nonlinear equations of motion appear to be different.
Explicit formulae for Yang-Mills-Einstein amplitudes from the double copy
DOE Office of Scientific and Technical Information (OSTI.GOV)
Chiodaroli, Marco; Günaydin, Murat; Johansson, Henrik
Using the double-copy construction of Yang-Mills-Einstein theories formulated in our earlier work, we obtain compact presentations for single-trace Yang-Mills-Einstein tree amplitudes with up to five external gravitons and an arbitrary number of gluons. These are written as linear combinations of color-ordered Yang-Mills trees, where the coefficients are given by color/kinematics-satisfying numerators in a Yang-Mills + φ 3 theory. The construction outlined in this paper holds in general dimension and extends straightforwardly to supergravity theories. For one, two, and three external gravitons, our expressions give identical or simpler presentations of amplitudes already constructed through string-theory considerations or the scattering equations formalism.more » Our results are based on color/kinematics duality and gauge invariance, and strongly hint at a recursive structure underlying the single-trace amplitudes with an arbitrary number of gravitons. We also present explicit expressions for all-loop single-graviton Einstein-Yang-Mills amplitudes in terms of Yang-Mills amplitudes and, through gauge invariance, derive new all-loop amplitude relations for Yang-Mills theory.« less
Explicit formulae for Yang-Mills-Einstein amplitudes from the double copy
Chiodaroli, Marco; Günaydin, Murat; Johansson, Henrik; ...
2017-07-03
Using the double-copy construction of Yang-Mills-Einstein theories formulated in our earlier work, we obtain compact presentations for single-trace Yang-Mills-Einstein tree amplitudes with up to five external gravitons and an arbitrary number of gluons. These are written as linear combinations of color-ordered Yang-Mills trees, where the coefficients are given by color/kinematics-satisfying numerators in a Yang-Mills + φ 3 theory. The construction outlined in this paper holds in general dimension and extends straightforwardly to supergravity theories. For one, two, and three external gravitons, our expressions give identical or simpler presentations of amplitudes already constructed through string-theory considerations or the scattering equations formalism.more » Our results are based on color/kinematics duality and gauge invariance, and strongly hint at a recursive structure underlying the single-trace amplitudes with an arbitrary number of gravitons. We also present explicit expressions for all-loop single-graviton Einstein-Yang-Mills amplitudes in terms of Yang-Mills amplitudes and, through gauge invariance, derive new all-loop amplitude relations for Yang-Mills theory.« less
Li, Xiangping; Yin, Tao; Zhong, Guangwei; Li, Wei; Luo, Yanhong; Xiang, Lingli; Liu, Zhehao
2011-07-01
To observe the herbal effects on hyperthyroidism patients with syndrome of hyperactivity of liver-Yang by method for calming the liver and suppressing Yang and investigate its effects on the lymphocyte protein expression. This approach may lay a foundation for the further investigation of the curative mechanisms of calming the liver and suppressing Yang treatment. A total of 48 hyperthyroidism patients with syndrome of hyperactivity of liver-Yang were randomly divided into treatment group and control group. The treatment group was treated by method for calming the liver and suppressing Yang in accordance with traditional Chinese medicine (TCM) and the control group with thiamazole tablets for three periods of treatment The therapeutic effects, the score of TCM symptom, electrocardiogram (P wave), thyroid hormones and ultrasound were observed in both groups before and after the treatment. The side effects in the treatment course were observed in both groups. The level of differential protein expression was analyzed by two-dimensional electrphoresis and matrix assisted laser desorption/ionizaton time-of-flight mass spectrometry. The treatment group has the effect on stepping down the heart rate, cutting down the P wave amplitude changes, regulating the level of thyroid hormones and decreasing the volume of thyromegaly. There are not statistically significant between the treatment group and control group. However, the treatment group has obviously better effect on regulating TCM symptom and decreasing the side reaction than the control group (P<0.05). There are not statistically significant on the total effective between the treatment group and control group. The average spots in lymphocyte for normal people, before and after treating hyperthyroidism patients with syndrome of hyperactivity of liver-Yang were (429 +/- 31), (452 +/- 28) and (437 +/- 36) spots respectively. Eight down-regulated protein expressions and 11 up-regulated protein expressions were obtained in
Jacobs, A. M.; Zingale, M.; Nonaka, A.; ...
2016-08-10
The dynamics of helium shell convection driven by nuclear burning establish the conditions for runaway in the sub-Chandrasekhar-mass, double-detonation model for SNe Ia, as well as for a variety of other explosive phenomena. In this paper, we explore these convection dynamics for a range of white dwarf core and helium shell masses in three dimensions using the low Mach number hydrodynamics code MAESTRO. We present calculations of the bulk properties of this evolution, including time-series evolution of global diagnostics, lateral averages of the 3D state, and the global 3D state. We find a variety of outcomes, including quasi-equilibrium, localized runaway,more » and convective runaway. Finally, our results suggest that the double-detonation progenitor model is promising and that 3D dynamic convection plays a key role.« less
Bäcklund Transformations in 10D SUSY Yang-Mills Theories
NASA Astrophysics Data System (ADS)
Gervais, Jean-Loup
A Bäcklund transformation is derived for the Yang's type (super) equations previously derived (hep-th/9811108) by M. Saveliev and the author, from the ten-dimensional super-Yang-Mills field equations in an on-shell light cone gauge. It is shown to be based upon a particular gauge transformation satisfying nonlinear conditions which ensure that the equations retain the same form. These Yang's type field equations are shown to be precisely such that they automatically provide a solution of these conditions. This Bäcklund transformation is similar to the one proposed by A. Leznov for self-dual Yang-Mills in four dimensions. In the introduction a personal recollection on the birth of supersymmetry is given.
on the formation of higher efficiency formamidinium lead triiodide-based solar cells," Chem -0003-2019-4298 Dr. Mengjin Yang received his Ph.D. in Materials Science from the University of Pittsburgh, where he investigated nanomaterials for solar energy conversion under the supervision of Prof
N = 2* Yang-Mills on the Lattice
NASA Astrophysics Data System (ADS)
Joseph, Anosh
2018-03-01
The N = 2* Yang-Mills theory in four dimensions is a non-conformal theory that appears as a mass deformation of maximally supersymmetric N = 4 Yang-Mills theory. This theory also takes part in the AdS/CFT correspondence and its gravity dual is type IIB supergravity on the Pilch-Warner background. The finite temperature properties of this theory have been studied recently in the literature. It has been argued that at large N and strong coupling this theory exhibits no thermal phase transition at any nonzero temperature. The low temperature N = 2* plasma can be compared to the QCD plasma. We provide a lattice construction of N = 2* Yang-Mills on a hypercubic lattice starting from the N = 4 gauge theory. The lattice construction is local, gauge-invariant, free from fermion doubling problem and preserves a part of the supersymmetry. This nonperturbative formulation of the theory can be used to provide a highly nontrivial check of the AdS/CFT correspondence in a non-conformal theory.
No-go for partially massless spin-2 Yang-Mills
Garcia-Saenz, Sebastian; Hinterbichler, Kurt; Joyce, Austin; ...
2016-02-05
There are various no-go results forbidding self-interactions for a single partially massless spin-2 field. Given the photon-like structure of the linear partially massless field, it is natural to ask whether a multiplet of such fields can interact under an internal Yang-Mills like extension of the partially massless symmetry. In this paper, we give two arguments that such a partially massless Yang-Mills theory does not exist. The first is that there is no Yang-Mills like non-abelian deformation of the partially massless symmetry, and the second is that cubic vertices with the appropriate structure constants do not exist.
ZN graded discrete Lax pairs and Yang-Baxter maps
NASA Astrophysics Data System (ADS)
Fordy, Allan P.; Xenitidis, Pavlos
2017-05-01
We recently introduced a class of ZN graded discrete Lax pairs and studied the associated discrete integrable systems (lattice equations). In this paper, we introduce the corresponding Yang-Baxter maps. Many well-known examples belong to this scheme for N=2, so, for N≥3, our systems may be regarded as generalizations of these. In particular, for each N we introduce a class of multi-component Yang-Baxter maps, which include H^{BIII (of Papageorgiou et al. 2010 SIGMA 6, 003 (9 p). (doi:10.3842/SIGMA.2010.033)), when N=2, and that associated with the discrete modified Boussinesq equation, for N=3. For N≥5 we introduce a new family of Yang-Baxter maps, which have no lower dimensional analogue. We also present new multi-component versions of the Yang-Baxter maps FIV and FV (given in the classification of Adler et al. 2004 Commun. Anal. Geom. 12, 967-1007. (doi:10.4310/CAG.2004.v12.n5.a1)).}
YANG-MILLS Theory in, Beyond, and Behind Observed Reality
NASA Astrophysics Data System (ADS)
Wilczek, Frank
The primary interactions of Yang-Mills theory [1] are visibly embodied in hard processes, most directly in jets. The character of jets also reflects the deep structure of effective charge, which is dominated by the influence of intrinsically non-Abelian gauge dynamics. These proven insights into fundamental physics ramify in many directions, and are far from being exhausted. I will discuss three rewarding explorations from my own experience, whose point of departure is the hard Yang-Mills interaction, and whose end is not yet in sight. Given an insight so profound and fruitful as Yang and Mills brought us, it is in order to try to consider its broadest implications, which I attempt at the end.
On integrability of the Yang-Baxter {sigma}-model
DOE Office of Scientific and Technical Information (OSTI.GOV)
Klimcik, Ctirad
2009-04-15
We prove that the recently introduced Yang-Baxter {sigma}-model can be considered as an integrable deformation of the principal chiral model. We find also an explicit one-to-one map transforming every solution of the principal chiral model into a solution of the deformed model. With the help of this map, the standard procedure of the dressing of the principal chiral solutions can be directly transferred into the deformed Yang-Baxter context.
Experimental realization of the Yang-Baxter Equation via NMR interferometry.
Vind, F Anvari; Foerster, A; Oliveira, I S; Sarthour, R S; Soares-Pinto, D O; Souza, A M; Roditi, I
2016-02-10
The Yang-Baxter equation is an important tool in theoretical physics, with many applications in different domains that span from condensed matter to string theory. Recently, the interest on the equation has increased due to its connection to quantum information processing. It has been shown that the Yang-Baxter equation is closely related to quantum entanglement and quantum computation. Therefore, owing to the broad relevance of this equation, besides theoretical studies, it also became significant to pursue its experimental implementation. Here, we show an experimental realization of the Yang-Baxter equation and verify its validity through a Nuclear Magnetic Resonance (NMR) interferometric setup. Our experiment was performed on a liquid state Iodotrifluoroethylene sample which contains molecules with three qubits. We use Controlled-transfer gates that allow us to build a pseudo-pure state from which we are able to apply a quantum information protocol that implements the Yang-Baxter equation.
Chandrasekhar-Kendall modes and Taylor relaxation in an axisymmetric torus
DOE Office of Scientific and Technical Information (OSTI.GOV)
Tang, X.Z.; Boozer, A.H.; Department of Applied Physics and Applied Mathematics, Columbia University, New York, New York 10027
2005-10-01
The helicity-conserving Taylor relaxation of a plasma in a toroidal chamber to a force-free configuration, which means j=(j{sub parallel})/B)B with j{sub parallel}/B independent of position, can be generalized to include the external injection of magnetic helicity. When this is done, j{sub parallel}/B has resonant values, which can be understood using the eigenmodes of Taylor-relaxed plasmas enclosed by a perfectly conducting toroidal shell. These eigenmodes include a toroidal generalization of those found by Chandrasekhar and Kendall (CK) [Astrophys. J. 126, 457 (1957)] for a spherical chamber, which has no externally produced magnetic flux. It is shown that the CK modes inmore » an axisymmetric torus are of three types: (1) helical modes as well as axisymmetric modes that have (2) and have no (3) net toroidal flux. Yoshida and Giga (YG) [Math. Z. 204, 235 (1990)] published a fourth class of modes: axisymmetric modes that have no net toroidal flux in the chamber due to toroidal flux produced by a net poloidal current in the shell canceling the net toroidal flux from the plasma currents. Jensen and Chu [Phys. Fluids 27, 2881 (1984)], as well as Taylor [Rev. Mod. Phys. 58, 741 (1986)], considered modes in which the vector potential was zero on the axisymmetric toroidal chamber. It is shown that these Jensen-Chu-Taylor modes include only the CK helical modes and the CK axisymmetric modes without net toroidal flux. If the toroidal chamber is perfectly conducting except for a cut that prevents a net poloidal current from flowing, resonances in j{sub parallel}/B occur at the eigenvalues of the axisymmetric CK modes. Jensen and Chu studied this type of resonance. Without the cut, so a poloidal current flows to conserve the net toroidal flux, it is shown that j{sub parallel}/B resonances occur at the eigenvalues of the CK modes that have no net toroidal flux and at the eigenvalues of the YG modes, which are upshifted from the eigenvalues of the axisymmetric CK modes
Tests of conformal field theory at the Yang-Lee singularity
DOE Office of Scientific and Technical Information (OSTI.GOV)
Wydro, Tomasz; McCabe, John F.
2009-12-14
This paper studies the Yang-Lee edge singularity of 2-dimensional (2D) Ising model based on a quantum spin chain and transfer matrix measurements on the cylinder. Based on finite-size scaling, the low-lying excitation spectrum is found at the Yang-Lee edge singularity. Based on transfer matrix techniques, the single structure constant is evaluated at the Yang-Lee edge singularity. The results of both types of measurements are found to be fully consistent with the predictions for the (A{sub 4}, A{sub 1}) minimal conformal field theory, which was previously identified with this critical point.
Aβ Damages Learning and Memory in Alzheimer's Disease Rats with Kidney-Yang Deficiency
Qi, Dongmei; Qiao, Yongfa; Zhang, Xin; Yu, Huijuan; Cheng, Bin; Qiao, Haifa
2012-01-01
Previous studies demonstrated that Alzheimer's disease was considered as the consequence produced by deficiency of Kidney essence. However, the mechanism underlying the symptoms also remains elusive. Here we report that spatial learning and memory, escape, and swimming capacities were damaged significantly in Kidney-yang deficiency rats. Indeed, both hippocampal Aβ 40 and 42 increases in Kidney-yang deficiency contribute to the learning and memory impairments. Specifically, damage of synaptic plasticity is involved in the learning and memory impairment of Kidney-yang deficiency rats. We determined that the learning and memory damage in Kidney-yang deficiency due to synaptic plasticity impairment and increases of Aβ 40 and 42 was not caused via NMDA receptor internalization induced by Aβ increase. β-Adrenergic receptor agonist can rescue the impaired long-term potential (LTP) in Kidney-yang rats. Taken together, our results suggest that spatial learning and memory inhibited in Kidney-yang deficiency might be induced by Aβ increase and the decrease of β 2 receptor function in glia. PMID:22645624
Spontaneously broken Yang-Mills-Einstein supergravities as double copies
DOE Office of Scientific and Technical Information (OSTI.GOV)
Chiodaroli, Marco; Günaydin, Murat; Johansson, Henrik
Color/kinematics duality and the double-copy construction have proved to be systematic tools for gaining new insight into gravitational theories. Extending our earlier work, in this article we introduce new double-copy constructions for large classes of spontaneously-broken Yang-Mills-Einstein theories with adjoint Higgs elds. One gaugetheory copy entering the construction is a spontaneously-broken (super-)Yang-Mills theory, while the other copy is a bosonic Yang-Mills-scalar theory with trilinear scalar interactions that display an explicitly-broken global symmetry. We show that the kinematic numerators of these gauge theories can be made to obey color/kinematics duality by exhibiting particular additional Lie-algebraic relations. We discuss in detail explicitmore » examples with N = 2 supersymmetry, focusing on Yang-Mills-Einstein supergravity theories belonging to the generic Jordan family in four and five dimensions, and identify the map between the supergravity and double-copy elds and parameters. We also briefly discuss the application of our results to N = 4 supergravity theories. The constructions are illustrated by explicit examples of tree-level and one-loop scattering amplitudes.« less
Spontaneously broken Yang-Mills-Einstein supergravities as double copies
Chiodaroli, Marco; Günaydin, Murat; Johansson, Henrik; ...
2017-06-13
Color/kinematics duality and the double-copy construction have proved to be systematic tools for gaining new insight into gravitational theories. Extending our earlier work, in this article we introduce new double-copy constructions for large classes of spontaneously-broken Yang-Mills-Einstein theories with adjoint Higgs elds. One gaugetheory copy entering the construction is a spontaneously-broken (super-)Yang-Mills theory, while the other copy is a bosonic Yang-Mills-scalar theory with trilinear scalar interactions that display an explicitly-broken global symmetry. We show that the kinematic numerators of these gauge theories can be made to obey color/kinematics duality by exhibiting particular additional Lie-algebraic relations. We discuss in detail explicitmore » examples with N = 2 supersymmetry, focusing on Yang-Mills-Einstein supergravity theories belonging to the generic Jordan family in four and five dimensions, and identify the map between the supergravity and double-copy elds and parameters. We also briefly discuss the application of our results to N = 4 supergravity theories. The constructions are illustrated by explicit examples of tree-level and one-loop scattering amplitudes.« less
Lee-Yang zero analysis for the study of QCD phase structure
DOE Office of Scientific and Technical Information (OSTI.GOV)
Ejiri, Shinji
2006-03-01
We comment on the Lee-Yang zero analysis for the study of the phase structure of QCD at high temperature and baryon number density by Monte-Carlo simulations. We find that the sign problem for nonzero density QCD induces a serious problem in the finite volume scaling analysis of the Lee-Yang zeros for the investigation of the order of the phase transition. If the sign problem occurs at large volume, the Lee-Yang zeros will always approach the real axis of the complex parameter plane in the thermodynamic limit. This implies that a scaling behavior which would suggest a crossover transition will notmore » be obtained. To clarify this problem, we discuss the Lee-Yang zero analysis for SU(3) pure gauge theory as a simple example without the sign problem, and then consider the case of nonzero density QCD. It is suggested that the distribution of the Lee-Yang zeros in the complex parameter space obtained by each simulation could be more important information for the investigation of the critical endpoint in the (T,{mu}{sub q}) plane than the finite volume scaling behavior.« less
Quantum Yang-Mills Dark Energy
NASA Astrophysics Data System (ADS)
Pasechnik, Roman
2016-02-01
In this short review, I discuss basic qualitative characteristics of quantum non-Abelian gauge dynamics in the non-stationary background of the expanding Universe in the framework of the standard Einstein--Yang--Mills formulation. A brief outlook of existing studies of cosmological Yang--Mills fields and their properties will be given. Quantum effects have a profound impact on the gauge field-driven cosmological evolution. In particular, a dynamical formation of the spatially-homogeneous and isotropic gauge field condensate may be responsible for both early and late-time acceleration, as well as for dynamical compensation of non-perturbative quantum vacua contributions to the ground state of the Universe. The main properties of such a condensate in the effective QCD theory at the flat Friedmann--Lema\\'itre--Robertson--Walker (FLRW) background will be discussed within and beyond perturbation theory. Finally, a phenomenologically consistent dark energy can be induced dynamically as a remnant of the QCD vacua compensation arising from leading-order graviton-mediated corrections to the QCD ground state.
Yang Monopoles and Emergent Three-Dimensional Topological Defects in Interacting Bosons
NASA Astrophysics Data System (ADS)
Yan, Yangqian; Zhou, Qi
2018-06-01
The Yang monopole as a zero-dimensional topological defect has been well established in multiple fields in physics. However, it remains an intriguing question to understand the interaction effects on Yang monopoles. Here, we show that the collective motion of many interacting bosons gives rise to exotic topological defects that are distinct from Yang monopoles seen by a single particle. Whereas interactions may distribute Yang monopoles in the parameter space or glue them to a single giant one of multiple charges, three-dimensional topological defects also arise from continuous manifolds of degenerate many-body eigenstates. Their projections in lower dimensions lead to knotted nodal lines and nodal rings. Our results suggest that ultracold bosonic atoms can be used to create emergent topological defects and directly measure topological invariants that are not easy to access in solids.
New contributions to physics by Prof. C. N. Yang: 2009-2011
NASA Astrophysics Data System (ADS)
Ma, Zhong-Qi
2016-01-01
In a seminal paper of 1967, Professor Chen Ning Yang found the full solution of the one-dimensional Fermi gas with a repulsive delta function interaction by using the Bethe ansatz and group theory. This work with a brilliant discovery of the Yang-Baxter equation has been inspiring new developments in mathematical physics, statistical physics, and many-body physics. Based on experimental developments in simulating many-body physics of one-dimensional systems of ultracold atoms, during a period from 2009 to 2011, Prof. Yang published seven papers on the exact properties of the ground state of bosonic and fermionic atoms with the repulsive delta function interaction and a confined potential to one dimension. Here I would like to share my experience in doing research work fortunately under the direct supervision of Prof. Yang in that period.
New Contributions to Physics by Prof. C. N. Yang: 2009-2011
NASA Astrophysics Data System (ADS)
Ma, Zhong-Qi
In a seminal paper of 1967, Professor Chen Ning Yang found the full solution of the one-dimensional Fermi gas with a repulsive delta function interaction by using the Bethe ansatz and group theory. This work with a brilliant discovery of the Yang-Baxter equation has been inspiring new developments in mathematical physics, statistical physics, and many-body physics. Based on experimental developments in simulating many-body physics of one-dimensional systems of ultracold atoms, during a period from 2009 to 2011, Prof. Yang published seven papers on the exact properties of the ground state of bosonic and fermionic atoms with the repulsive delta function interaction and a confined potential to one dimension. Here I would like to share my experience in doing research work fortunately under the direct supervision of Prof. Yang in that period.
ℤ3 parafermionic chain emerging from Yang-Baxter equation.
Yu, Li-Wei; Ge, Mo-Lin
2016-02-23
We construct the 1D ℤ3 parafermionic model based on the solution of Yang-Baxter equation and express the model by three types of fermions. It is shown that the ℤ3 parafermionic chain possesses both triple degenerate ground states and non-trivial topological winding number. Hence, the ℤ3 parafermionic model is a direct generalization of 1D ℤ2 Kitaev model. Both the ℤ2 and ℤ3 model can be obtained from Yang-Baxter equation. On the other hand, to show the algebra of parafermionic tripling intuitively, we define a new 3-body Hamiltonian H123 based on Yang-Baxter equation. Different from the Majorana doubling, the H123 holds triple degeneracy at each of energy levels. The triple degeneracy is protected by two symmetry operators of the system, ω-parity P [formula in text] and emergent parafermionic operator Γ, which are the generalizations of parity PM and emergent Majorana operator in Lee-Wilczek model, respectively. Both the ℤ3 parafermionic model and H123 can be viewed as SU(3) models in color space. In comparison with the Majorana models for SU(2), it turns out that the SU(3) models are truly the generalization of Majorana models resultant from Yang-Baxter equation.
Masslessness of ghosts in equivariantly gauge-fixed Yang-Mills theories
DOE Office of Scientific and Technical Information (OSTI.GOV)
Golterman, Maarten; Zimmerman, Leah
2005-06-01
We show that the one-loop ghost self-energy in an equivariantly gauge-fixed Yang-Mills theory vanishes at zero momentum. A ghost mass is forbidden by equivariant BRST symmetry, and our calculation confirms this explicitly. The four-ghost self interaction which appears in the equivariantly gauge-fixed Yang-Mills theory is needed in order to obtain this result.
Deconfinement in Yang-Mills Theory through Toroidal Compactification
DOE Office of Scientific and Technical Information (OSTI.GOV)
Simic, Dusan; Unsal, Mithat; /Stanford U., Phys. Dept. /SLAC
2011-08-12
We introduce field theory techniques through which the deconfinement transition of four-dimensional Yang-Mills theory can be moved to a semi-classical domain where it becomes calculable using two-dimensional field theory. We achieve this through a double-trace deformation of toroidally compactified Yang-Mills theory on R{sup 2} x S{sub L}{sup 1} x S{sub {beta}}{sup 1}. At large N, fixed-L, and arbitrary {beta}, the thermodynamics of the deformed theory is equivalent to that of ordinary Yang-Mills theory at leading order in the large N expansion. At fixed-N, small L and a range of {beta}, the deformed theory maps to a two-dimensional theory with electricmore » and magnetic (order and disorder) perturbations, analogs of which appear in planar spin-systems and statistical physics. We show that in this regime the deconfinement transition is driven by the competition between electric and magnetic perturbations in this two-dimensional theory. This appears to support the scenario proposed by Liao and Shuryak regarding the magnetic component of the quark-gluon plasma at RHIC.« less
Beauty and physics: 13 important contributions of Chen Ning Yang
NASA Astrophysics Data System (ADS)
Shi, Yu
2014-06-01
In 2012, Chen Ning Yang received a 90th birthday gift in the form of a black cube inscribed with his 13 most important contributions, which cover four major areas of physics: statistical mechanics, condensed matter physics, particle physics and field theory. We briefly describe these 13 contributions and make general comments about Yang's distinctive style as a trailblazing leader in research.
Generalizations of the classical Yang-Baxter equation and O-operators
NASA Astrophysics Data System (ADS)
Bai, Chengming; Guo, Li; Ni, Xiang
2011-06-01
Tensor solutions (r-matrices) of the classical Yang-Baxter equation (CYBE) in a Lie algebra, obtained as the classical limit of the R-matrix solution of the quantum Yang-Baxter equation, is an important structure appearing in different areas such as integrable systems, symplectic geometry, quantum groups, and quantum field theory. Further study of CYBE led to its interpretation as certain operators, giving rise to the concept of {O}-operators. The O-operators were in turn interpreted as tensor solutions of CYBE by enlarging the Lie algebra [Bai, C., "A unified algebraic approach to the classical Yang-Baxter equation," J. Phys. A: Math. Theor. 40, 11073 (2007)], 10.1088/1751-8113/40/36/007. The purpose of this paper is to extend this study to a more general class of operators that were recently introduced [Bai, C., Guo, L., and Ni, X., "Nonabelian generalized Lax pairs, the classical Yang-Baxter equation and PostLie algebras," Commun. Math. Phys. 297, 553 (2010)], 10.1007/s00220-010-0998-7 in the study of Lax pairs in integrable systems. Relations between O-operators, relative differential operators, and Rota-Baxter operators are also discussed.
Cluster-enriched Yang-Baxter equation from SUSY gauge theories
NASA Astrophysics Data System (ADS)
Yamazaki, Masahito
2018-04-01
We propose a new generalization of the Yang-Baxter equation, where the R-matrix depends on cluster y-variables in addition to the spectral parameters. We point out that we can construct solutions to this new equation from the recently found correspondence between Yang-Baxter equations and supersymmetric gauge theories. The S^2 partition function of a certain 2d N=(2,2) quiver gauge theory gives an R-matrix, whereas its FI parameters can be identified with the cluster y-variables.
[Formula: see text] graded discrete Lax pairs and Yang-Baxter maps.
Fordy, Allan P; Xenitidis, Pavlos
2017-05-01
We recently introduced a class of [Formula: see text] graded discrete Lax pairs and studied the associated discrete integrable systems (lattice equations). In this paper, we introduce the corresponding Yang-Baxter maps. Many well-known examples belong to this scheme for N =2, so, for N ≥3, our systems may be regarded as generalizations of these. In particular, for each N we introduce a class of multi-component Yang-Baxter maps, which include H B III (of Papageorgiou et al. 2010 SIGMA 6, 003 (9 p). (doi:10.3842/SIGMA.2010.033)), when N =2, and that associated with the discrete modified Boussinesq equation, for N =3. For N ≥5 we introduce a new family of Yang-Baxter maps, which have no lower dimensional analogue. We also present new multi-component versions of the Yang-Baxter maps F IV and F V (given in the classification of Adler et al. 2004 Commun. Anal. Geom. 12, 967-1007. (doi:10.4310/CAG.2004.v12.n5.a1)).
Super Yang-Mills theory with impurity walls and instanton moduli spaces
NASA Astrophysics Data System (ADS)
Cherkis, Sergey A.; O'Hara, Clare; Sämann, Christian
2011-06-01
We explore maximally supersymmetric Yang-Mills theory with walls of impurities respecting half of the supersymmetries. The walls carry fundamental or bifundamental matter multiplets. We employ three-dimensional N=2 superspace language to identify the Higgs branch of this theory. We find that the vacuum conditions determining the Higgs branch are exactly the bow equations yielding Yang-Mills instantons on a multi-Taub-NUT space. Under electric-magnetic duality, the super Yang-Mills theory describing the bulk is mapped to itself, while the fundamental- and bifundamental-carrying impurity walls are interchanged. We perform a one-loop computation on the Coulomb branch of the dual theory to find the asymptotic metric on the original Higgs branch.
Non-Abelian Yang-Mills analogue of classical electromagnetic duality
DOE Office of Scientific and Technical Information (OSTI.GOV)
Chan, Hong-Mo; Faridani, J.; Tsun, T.S.
The classic question of non-Abelian Yang-Mills analogue to electromagnetic duality is examined here in a minimalist fashion at the strictly four-dimensional, classical field, and point charge level. A generalization of the Abelian Hodge star duality is found which, though not yet known to give dual symmetry, reproduces analogues to many dual properties of the Abelian theory. For example, there is a dual potential, but it is a two-indexed tensor {ital T}{sub {mu}{nu}} of the Freedman-Townsend-type. Though not itself functioning as such, {ital T}{sub {mu}{nu}} gives rise to a dual parallel transport {ital {tilde A}}{sub {mu}} for the phase of themore » wave function of the color magnetic charge, this last being a monopole of the Yang-Mills field but a source of the dual field. The standard color (electric) charge itself is found to be a monpole of {ital {tilde A}}{sub {mu}}. At the same time, the gauge symmetry is found doubled from say SU({ital N}) to SU({ital N}){times}SU({ital N}). A novel feature is that all equations of motion, including the standard Yang-Mills and Wong equations, are here derived from a ``universal`` principle, namely, the Wu-Yang criterion for monpoles, where interactions arise purely as a consequence of the topological definition of the monopole charge. The technique used is the loop space formulation of Polyakov.« less
The Hom-Yang-Baxter equation and Hom-Lie algebras
DOE Office of Scientific and Technical Information (OSTI.GOV)
Yau, Donald
2011-05-15
Motivated by recent work on Hom-Lie algebras, a twisted version of the Yang-Baxter equation, called the Hom-Yang-Baxter equation (HYBE), was introduced by Yau [J. Phys. A 42, 165202 (2009)]. In this paper, several more classes of solutions of the HYBE are constructed. Some of the solutions of the HYBE are closely related to the quantum enveloping algebra of sl(2), the Jones-Conway polynomial, and Yetter-Drinfel'd modules. Under some invertibility conditions, we construct a new infinite sequence of solutions of the HYBE from a given one.
Yang-Mills Theory at 60: Milestones, Landmarks and Interesting Questions
NASA Astrophysics Data System (ADS)
Chau, Ling-Lie
On the auspicious occasion of celebrating the 60th anniversary of the Yang-Mills theory, and Professor Yang's many other important contributions to physics and mathematics, I will highlight the impressive milestones and landmarks that have been established in the last 60 years, as well as some interesting questions that are worthy of answers from future researches. The paper is written (without equations) for the interest of non-scientists as well as of scientists.
[Plasma metabonomics of Guifu Dihuang Wan in the treatment of yang deficiency].
Xiao, Ya; Jing, Yuan; Chen, Jie-Yu; Li, Fei; Cheng, Jing-Ru; Bi, Jian-Lu; Luo, Ren; Zhao, Xiao-Shan
2016-11-20
To assess the effect of Guifu Dihuang Wan (GFDHW) in the treatment of yang deficiency and explore the underlying molecular mechanism. Sixty-two participants without diseases were randomized into control group (n=31) and experimental group (n=31) and were given lifestyle intervention additional GFDHW treatment for a month. NMR technology was used for metabonomics analysis. Intervention with GFDHW resulted in significantly decreased conversion scores of yang deficiency in the experimental group compared with the control group (P<0.005). The concentrations of lactate, valine, proline, arginine and 3-hydroxybutyrate were increased in the plasma of yang-deficient subjects after lifestyle intervention. GFDHW treatment with lifestyle intervention significantly increased the concentrations of lactate, valine, proline, arginine and 3-hydroxybutyrate and also the levels of alanine, glutamine, alpha glucose, isoleucine, betaine and propylene glycol. GFDHW treatment improves yang deficiency possibly by increasing the concentrations of alanine, glutamine, alpha glucose, isoleucine, betaine and propylene glycol and promoting energy metabolism of the body.
Pay Attention to the Phrasal Structures: Going beyond T-Units--A Response to Weiwei Yang
ERIC Educational Resources Information Center
Biber, Douglas; Gray, Bethany; Poonpon, Kornwipa
2013-01-01
WeiWei Yang, in her forum piece, raises two main criticisms of the authors' "TQ" article on grammatical complexity: "The study the authors conducted [1] is not capable of answering development-related questions and [2] is mathematically questionable" (Yang, 2013, p. 190). In addition, Yang's article has a third goal that is not explicitly…
HYM-flation: Yang-Mills cosmology with Horndeski coupling
NASA Astrophysics Data System (ADS)
Davydov, E.; Gal'tsov, D.
2016-02-01
We propose new mechanism for inflation using classical SU (2) Yang-Mills (YM) homogeneous and isotropic field non-minimally coupled to gravity via Horndeski prescription. This is the unique generally and gauge covariant ghost-free YM theory with the curvature-dependent action leading to second-order gravity and Yang-Mills field equations. We show that its solution space contains de Sitter boundary to which the trajectories are attracted for some finite time, ensuring the robust inflation with a graceful exit. The theory can be generalized to include the Higgs field leading to two-steps inflationary scenario, in which the Planck-scale YM-generated inflation naturally prepares the desired initial conditions for the GUT-scale Higgs inflation.
Solutions to Yang-Mills Equations on Four-Dimensional de Sitter Space
NASA Astrophysics Data System (ADS)
Ivanova, Tatiana A.; Lechtenfeld, Olaf; Popov, Alexander D.
2017-08-01
We consider pure SU(2) Yang-Mills theory on four-dimensional de Sitter space dS4 and construct a smooth and spatially homogeneous magnetic solution to the Yang-Mills equations. Slicing dS4 as R ×S3, via an SU(2)-equivariant ansatz, we reduce the Yang-Mills equations to ordinary matrix differential equations and further to Newtonian dynamics in a double-well potential. Its local maximum yields a Yang-Mills solution whose color-magnetic field at time τ ∈R is given by B˜a=-1/2 Ia/(R2cosh2τ ), where Ia for a =1 , 2, 3 are the SU(2) generators and R is the de Sitter radius. At any moment, this spatially homogeneous configuration has finite energy, but its action is also finite and of the value -1/2 j (j +1 )(2 j +1 )π3 in a spin-j representation. Similarly, the double-well bounce produces a family of homogeneous finite-action electric-magnetic solutions with the same energy. There is a continuum of other solutions whose energy and action extend down to zero.
Vafa-Witten theorem and Lee-Yang singularities
DOE Office of Scientific and Technical Information (OSTI.GOV)
Aguado, M.; Asorey, M.
2009-12-15
We prove the analyticity of the finite volume QCD partition function for complex values of the {theta}-vacuum parameter. The absence of singularities different from Lee-Yang zeros only permits and cusp singularities in the vacuum energy density and never or cusps. This fact together with the Vafa-Witten diamagnetic inequality implies the vanishing of the density of Lee-Yang zeros at {theta}=0 and has an important consequence: the absence of a first order phase transition at {theta}=0. The result provides a key missing link in the Vafa-Witten proof of parity symmetry conservation in vectorlike gauge theories and follows from renormalizability, unitarity, positivity, andmore » existence of Bogomol'nyi-Prasad-Sommerfield bounds. Generalizations of this theorem to other physical systems are also discussed, with particular interest focused on the nonlinear CP{sup N} sigma model.« less
The Stack of Yang-Mills Fields on Lorentzian Manifolds
NASA Astrophysics Data System (ADS)
Benini, Marco; Schenkel, Alexander; Schreiber, Urs
2018-03-01
We provide an abstract definition and an explicit construction of the stack of non-Abelian Yang-Mills fields on globally hyperbolic Lorentzian manifolds. We also formulate a stacky version of the Yang-Mills Cauchy problem and show that its well-posedness is equivalent to a whole family of parametrized PDE problems. Our work is based on the homotopy theoretical approach to stacks proposed in Hollander (Isr. J. Math. 163:93-124, 2008), which we shall extend by further constructions that are relevant for our purposes. In particular, we will clarify the concretification of mapping stacks to classifying stacks such as BG con.
Long, Yong-Ling; Li, Zheng-Mu
2013-07-01
To observe the effect of Jingui Shenqi Pill (JSP) and its disassembled recipes (supplementing Shen yang, supplementing Shen yin, and supplementing Shen yang and Shen yin) on ovarian functions of female rats of Shen yang deficiency syndrome (SYDS). Totally 55 SD female rats were randomly divided into 5 groups, i.e., the normal control group, the model group, the Shen yang supplementing group, the Shen yin supplementing group, the Shen yang and Shen yin supplementing group, 11 in each group. Except the normal control group, rats in the rest group were injected with hydrocortisone at the daily dose of 25 mg/kg at the muscle of femoribus internus for 12 successive days. From the 13th day after successful modeling, rats were administered by gastrogavage with different recipes at the dose of 1 mL/100 g (2.75 g/kg Shen yang supplementing recipe; 6.25 g/kg Shen yin supplementing recipe; 6.75 g/kg JSP), once daily for 20 successive days. Equal volume of normal saline was given to those in the normal control group and the model group, once daily for 20 successive days. Blood was withdrawn from the orbit on the 2nd day after intervention. The serum estradiol (E2) and progesterone (P) were detected using ELISA. The weight of uterus and ovarian index (VI) were calculated. The pathological changes were observed by HE staining. The general condition of rats in the Shen yang and Shen yin supplementing group were improved. The body weight (g) was added by 35.0 +/- 12.5 in the normal control group, 16.7 +/- 7.4 in the model group, 20.2 +/- 6.9 in the Shen yang supplementing group, 18.3 +/- 3.6 in the Shen yin supplementing group, and 29.4 +/- 12.2 in the Shen yang and Shen yin supplementing group. The uterus VI (mg/100 g) was 183.4 +/- 11.6 in the normal control group,144.0 +/- 6.5 in the model group,158.7 +/- 6.3 in the Shen yang supplementing group,152.1 +/- 6.9 in the Shen yin supplementing group, and 172.8 +/- 8.1 in the Shen yang and Shen yin supplementing group. The ovarian VI
Color Memory: A Yang-Mills Analog of Gravitational Wave Memory.
Pate, Monica; Raclariu, Ana-Maria; Strominger, Andrew
2017-12-29
A transient color flux across null infinity in classical Yang-Mills theory is considered. It is shown that a pair of test "quarks" initially in a color singlet generically acquire net color as a result of the flux. A nonlinear formula is derived for the relative color rotation of the quarks. For a weak color flux, the formula linearizes to the Fourier transform of the soft gluon theorem. This color memory effect is the Yang-Mills analog of the gravitational memory effect.
Color Memory: A Yang-Mills Analog of Gravitational Wave Memory
NASA Astrophysics Data System (ADS)
Pate, Monica; Raclariu, Ana-Maria; Strominger, Andrew
2017-12-01
A transient color flux across null infinity in classical Yang-Mills theory is considered. It is shown that a pair of test "quarks" initially in a color singlet generically acquire net color as a result of the flux. A nonlinear formula is derived for the relative color rotation of the quarks. For a weak color flux, the formula linearizes to the Fourier transform of the soft gluon theorem. This color memory effect is the Yang-Mills analog of the gravitational memory effect.
Higgs Amplitudes from N=4 Supersymmetric Yang-Mills Theory.
Brandhuber, Andreas; Kostacińska, Martyna; Penante, Brenda; Travaglini, Gabriele
2017-10-20
Higgs plus multigluon amplitudes in QCD can be computed in an effective Lagrangian description. In the infinite top-mass limit, an amplitude with a Higgs boson and n gluons is computed by the form factor of the operator TrF^{2}. Up to two loops and for three gluons, its maximally transcendental part is captured entirely by the form factor of the protected stress tensor multiplet operator T_{2} in N=4 supersymmetric Yang-Mills theory. The next order correction involves the calculation of the form factor of the higher-dimensional, trilinear operator TrF^{3}. We present explicit results at two loops for three gluons, including the subleading transcendental terms derived from a particular descendant of the Konishi operator that contains TrF^{3}. These are expressed in terms of a few universal building blocks already identified in earlier calculations. We show that the maximally transcendental part of this quantity, computed in nonsupersymmetric Yang-Mills theory, is identical to the form factor of another protected operator, T_{3}, in the maximally supersymmetric theory. Our results suggest that the maximally transcendental part of Higgs amplitudes in QCD can be entirely computed through N=4 super Yang-Mills theory.
Analysis of Ward identities in supersymmetric Yang-Mills theory
NASA Astrophysics Data System (ADS)
Ali, Sajid; Bergner, Georg; Gerber, Henning; Montvay, Istvan; Münster, Gernot; Piemonte, Stefano; Scior, Philipp
2018-05-01
In numerical investigations of supersymmetric Yang-Mills theory on a lattice, the supersymmetric Ward identities are valuable for finding the critical value of the hopping parameter and for examining the size of supersymmetry breaking by the lattice discretisation. In this article we present an improved method for the numerical analysis of supersymmetric Ward identities, which takes into account the correlations between the various observables involved. We present the first complete analysis of supersymmetric Ward identities in N=1 supersymmetric Yang-Mills theory with gauge group SU(3). The results indicate that lattice artefacts scale to zero as O(a^2) towards the continuum limit in agreement with theoretical expectations.
CP Symmetry, Lee-Yang zeros and Phase Transitions
DOE Office of Scientific and Technical Information (OSTI.GOV)
Aguado, M.; Asorey, M.
2011-05-23
We analyze the analytic properties of {theta}-vacuum in QCD and its connection with spontaneous symmetry breaking of CP symmetry. A loss of analyticity in the {theta}-vacuum energy density can only be due to the accumulation of Lee-Yang zeros at some real values of {theta}. In the case of first order transitions these singularities are always associated to and cusp singularities and never to or cusps, which in the case {theta} = 0 are incompatible with the Vafa-Witten diamagnetic inequality This fact provides a key missing link in the Vafa-Witten proof of parity symmetry conservation in vector-like gauge theories like QCD.more » The argument is very similar to that used in the derivation of Bank-Casher formula for chiral symmetry breaking. However, the and behavior does not exclude the existence of a first phase transition at {theta} = {pi}, where a and cusp singularity is not forbidden by any inequality; in this case the topological charge condensate is proportional to the density of Lee-Yang zeros at {theta} = {pi}. Moreover, Lee-Yang zeros could give rise to a second order phase transition at {theta} = 0, which might be very relevant for the interpretation of the anomalous behavior of the topological susceptibility in the CP{sup 1} sigma model.« less
Yang-Baxter σ -models, conformal twists, and noncommutative Yang-Mills theory
NASA Astrophysics Data System (ADS)
Araujo, T.; Bakhmatov, I.; Colgáin, E. Ó.; Sakamoto, J.; Sheikh-Jabbari, M. M.; Yoshida, K.
2017-05-01
The Yang-Baxter σ -model is a systematic way to generate integrable deformations of AdS5×S5 . We recast the deformations as seen by open strings, where the metric is undeformed AdS5×S5 with constant string coupling, and all information about the deformation is encoded in the noncommutative (NC) parameter Θ . We identify the deformations of AdS5 as twists of the conformal algebra, thus explaining the noncommutativity. We show that the unimodularity condition on r -matrices for supergravity solutions translates into Θ being divergence-free. Integrability of the σ -model for unimodular r -matrices implies the existence and planar integrability of the dual NC gauge theory.
Confinement, holonomy, and correlated instanton-dyon ensemble: SU(2) Yang-Mills theory
NASA Astrophysics Data System (ADS)
Lopez-Ruiz, Miguel Angel; Jiang, Yin; Liao, Jinfeng
2018-03-01
The mechanism of confinement in Yang-Mills theories remains a challenge to our understanding of nonperturbative gauge dynamics. While it is widely perceived that confinement may arise from chromomagnetically charged gauge configurations with nontrivial topology, it is not clear what types of configurations could do that and how, in pure Yang-Mills and QCD-like (nonsupersymmetric) theories. Recently, a promising approach has emerged, based on statistical ensembles of dyons/anti-dyons that are constituents of instanton/anti-instanton solutions with nontrivial holonomy where the holonomy plays a vital role as an effective "Higgsing" mechanism. We report a thorough numerical investigation of the confinement dynamics in S U (2 ) Yang-Mills theory by constructing such a statistical ensemble of correlated instanton-dyons.
Noncommutative Yang-Mills from equivalence of star products
NASA Astrophysics Data System (ADS)
Jurčo, B.; Schupp, P.
2000-05-01
It is shown that the transformation between ordinary and noncommutative Yang-Mills theory as formulated by Seiberg and Witten is due to the equivalence of certain star products on the D-brane world-volume.
Glueball spectra from a matrix model of pure Yang-Mills theory
NASA Astrophysics Data System (ADS)
Acharyya, Nirmalendu; Balachandran, A. P.; Pandey, Mahul; Sanyal, Sambuddha; Vaidya, Sachindeo
2018-05-01
We present variational estimates for the low-lying energies of a simple matrix model that approximates SU(3) Yang-Mills theory on a three-sphere of radius R. By fixing the ground state energy, we obtain the (integrated) renormalization group (RG) equation for the Yang-Mills coupling g as a function of R. This RG equation allows to estimate the mass of other glueball states, which we find to be in excellent agreement with lattice simulations.
Yang-Mills matrix mechanics and quantum phases
NASA Astrophysics Data System (ADS)
Pandey, Mahul; Vaidya, Sachindeo
The SU(2) Yang-Mills matrix model coupled to fundamental fermions is studied in the adiabatic limit, and quantum critical behavior is seen at special corners of the gauge field configuration space. The quantum scalar potential for the gauge field induced by the fermions diverges at the corners, and is intimately related to points of enhanced degeneracy of the fermionic Hamiltonian. This in turn leads to superselection sectors in the Hilbert space of the gauge field, the ground states in different sectors being orthogonal to each other. The SU(2) Yang-Mills matrix model coupled to two Weyl fermions has three quantum phases. When coupled to a massless Dirac fermion, the number of quantum phases is four. One of these phases is the color-spin locked phase. This paper is an extended version of the lectures given by the second author (SV) at the International Workshop on Quantum Physics: Foundations and Applications, Bangalore, in February 2016, and is based on [1].
A BRST gauge-fixing procedure for Yang Mills theory on sphere
NASA Astrophysics Data System (ADS)
Banerjee, Rabin; Deguchi, Shinichi
2006-01-01
A gauge-fixing procedure for the Yang-Mills theory on an n-dimensional sphere (or a hypersphere) is discussed in a systematic manner. We claim that Adler's gauge-fixing condition used in massless Euclidean QED on a hypersphere is not conventional because of the presence of an extra free index, and hence is unfavorable for the gauge-fixing procedure based on the BRST invariance principle (or simply BRST gauge-fixing procedure). Choosing a suitable gauge condition, which is proved to be equivalent to a generalization of Adler's condition, we apply the BRST gauge-fixing procedure to the Yang-Mills theory on a hypersphere to obtain consistent results. Field equations for the Yang-Mills field and associated fields are derived in manifestly O (n + 1) covariant or invariant forms. In the large radius limit, these equations reproduce the corresponding field equations defined on the n-dimensional flat space.
An instability of hyperbolic space under the Yang-Mills flow
DOE Office of Scientific and Technical Information (OSTI.GOV)
Gegenberg, Jack; Day, Andrew C.; Liu, Haitao
2014-04-15
We consider the Yang-Mills flow on hyperbolic 3-space. The gauge connection is constructed from the frame-field and (not necessarily compatible) spin connection components. The fixed points of this flow include zero Yang-Mills curvature configurations, for which the spin connection has zero torsion and the associated Riemannian geometry is one of constant curvature. We analytically solve the linearized flow equations for a large class of perturbations to the fixed point corresponding to hyperbolic 3-space. These can be expressed as a linear superposition of distinct modes, some of which are exponentially growing along the flow. The growing modes imply the divergence ofmore » the (gauge invariant) perturbative torsion for a wide class of initial data, indicating an instability of the background geometry that we confirm with numeric simulations in the partially compactified case. There are stable modes with zero torsion, but all the unstable modes are torsion-full. This leads us to speculate that the instability is induced by the torsion degrees of freedom present in the Yang-Mills flow.« less
Mu, Chun-sun; Zhang, Ping; Kong, Chun-yan; Li, Yang-ning
2015-09-01
To study the application of Bayes probability model in differentiating yin and yang jaundice syndromes in neonates. Totally 107 jaundice neonates who admitted to hospital within 10 days after birth were assigned to two groups according to syndrome differentiation, 68 in the yang jaundice syndrome group and 39 in the yin jaundice syndrome group. Data collected for neonates were factors related to jaundice before, during and after birth. Blood routines, liver and renal functions, and myocardial enzymes were tested on the admission day or the next day. Logistic regression model and Bayes discriminating analysis were used to screen factors important for yin and yang jaundice syndrome differentiation. Finally, Bayes probability model for yin and yang jaundice syndromes was established and assessed. Factors important for yin and yang jaundice syndrome differentiation screened by Logistic regression model and Bayes discriminating analysis included mothers' age, mother with gestational diabetes mellitus (GDM), gestational age, asphyxia, or ABO hemolytic diseases, red blood cell distribution width (RDW-SD), platelet-large cell ratio (P-LCR), serum direct bilirubin (DBIL), alkaline phosphatase (ALP), cholinesterase (CHE). Bayes discriminating analysis was performed by SPSS to obtain Bayes discriminant function coefficient. Bayes discriminant function was established according to discriminant function coefficients. Yang jaundice syndrome: y1= -21. 701 +2. 589 x mother's age + 1. 037 x GDM-17. 175 x asphyxia + 13. 876 x gestational age + 6. 303 x ABO hemolytic disease + 2.116 x RDW-SD + 0. 831 x DBIL + 0. 012 x ALP + 1. 697 x LCR + 0. 001 x CHE; Yin jaundice syndrome: y2= -33. 511 + 2.991 x mother's age + 3.960 x GDM-12. 877 x asphyxia + 11. 848 x gestational age + 1. 820 x ABO hemolytic disease +2. 231 x RDW-SD +0. 999 x DBIL +0. 023 x ALP +1. 916 x LCR +0. 002 x CHE. Bayes discriminant function was hypothesis tested and got Wilks' λ =0. 393 (P =0. 000). So Bayes
Perturbation Theory of Massive Yang-Mills Fields
DOE R&D Accomplishments Database
Veltman, M.
1968-08-01
Perturbation theory of massive Yang-Mills fields is investigated with the help of the Bell-Treiman transformation. Diagrams containing one closed loop are shown to be convergent if there are more than four external vector boson lines. The investigation presented does not exclude the possibility that the theory is renormalizable.
Yang-Monti Principle in Bridging Long Ureteral Defects: Cases Report and A Systemic Review.
Bao, Jun Sheng; He, Qiqi; Li, Yuzhuo; Shi, Wei; Wu, Gongjin; Yue, Zhongjin
2017-07-02
Ureteric substitution using the Yang-Monti principle was reported as a modification of simple ileal ureter replacement. During April 2013 to June in 2015, 2 patients underwent ileal ureteral substitution using a reconfigured ileal segment of Yang Monti principle in our clinical center. Some slight modifications were made and then follow-up were carried out up to 12 months. For these 2 cases, no significant intra/post-operative complications occurred. In 1 year follow up, serum creatinine (Scr) and blood urea nitrogen (BUN) of both patients decreased to normal.Glomerular filtration rate (GFR), renogram and pyelogram showed a stable split renal function. To better understand the Yang-Monti principle and potential risks and complications, we conduct an systemic review by searching PubMed, Google Scholar and the Cochrane Library database from January 1996 through June 2016. 10 out of 644 publications were identified, which included 269 patients from cohort studies. The most usual indications for Yang-monti therapy were iatrogenic stricture and retroperitoneal fibrosis. Infection and ileus were indicated as themain short time postoperative complications while the fistula and re- strictures happened in long-term. In general,we believe Yang-Monti Principle is a safer and efficient technique for clinical partial and complete ureteral defects if patients and potential risks could be well prepared.
Yu, Ruoxi; Yang, Yin; Han, Yuanyuan; Hou, Pengwei; Li, Yingshuai; Li, Siqi
2016-01-01
Objectives. Differences among healthy subjects and associated disease risks are of substantial interest in clinical medicine. According to the theory of “constitution-disease correlation” in traditional Chinese medicine, we try to find out if there is any connection between intolerance of cold in Yang deficiency constitution and molecular evidence and if there is any gene expression basis in specific disorders. Methods. Peripheral blood mononuclear cells were collected from Chinese Han individuals with Yang deficiency constitution (n = 20) and balanced constitution (n = 8) (aged 18–28) and global gene expression profiles were determined between them using the Affymetrix HG-U133 Plus 2.0 array. Results. The results showed that when the fold change was ≥1.2 and q ≤ 0.05, 909 genes were upregulated in the Yang deficiency constitution, while 1189 genes were downregulated. According to our research differential genes found in Yang deficiency constitution were usually related to lower immunity, metabolic disorders, and cancer tendency. Conclusion. Gene expression disturbance exists in Yang deficiency constitution, which corresponds to the concept of constitution and gene classification. It also suggests people with Yang deficiency constitution are susceptible to autoimmune diseases, enteritis, arthritis, metabolism disorders, and cancer, which provides molecular evidence for the theory of “constitution-disease correlation.” PMID:28484499
NASA Astrophysics Data System (ADS)
Stritzinger, M. D.; Valenti, S.; Hoeflich, P.; Baron, E.; Phillips, M. M.; Taddia, F.; Foley, R. J.; Hsiao, E. Y.; Jha, S. W.; McCully, C.; Pandya, V.; Simon, J. D.; Benetti, S.; Brown, P. J.; Burns, C. R.; Campillay, A.; Contreras, C.; Förster, F.; Holmbo, S.; Marion, G. H.; Morrell, N.; Pignata, G.
2015-01-01
We present ultraviolet through near-infrared (NIR) broadband photometry, and visual-wavelength and NIR spectroscopy of the Type Iax supernova (SN) 2012Z. The data set consists of both early- and late-time observations, including the first late phase NIR spectrum obtained for a spectroscopically classified SN Iax. Simple model calculations of its bolometric light curve suggest SN 2012Z produced ~0.3 M⊙ of 56Ni, ejected about a Chandrasekhar mass of material, and had an explosion energy of ~1051 erg, making it one of the brightest (MB = -18.3 mag) and most energetic SN Iax yet observed. The late phase (+269d) NIRspectrum of SN 2012Z is found to broadly resemble similar epoch spectra of normal SNe Ia; however, like other SNe Iax, corresponding visual-wavelength spectra differ substantially from all supernova types. Constraints from the distribution of intermediate mass elements, e.g., silicon and magnesium, indicate that the outer ejecta did not experience significant mixing during or after burning, and the late phase NIR line profiles suggests most of the 56Ni is produced during high density burning. The various observational properties of SN 2012Z are found to be consistent with the theoretical expectations of a Chandrasekhar mass white dwarf progenitor that experiences a pulsational delayed detonation, which produced several tenths of a solar mass of 56Ni during the deflagration burning phase and little (or no) 56Ni during the detonation phase. Within this scenario only a moderate amount of Rayleigh-Taylor mixing occurs both during the deflagration and fallback phase of the pulsation, and the layered structure of the intermediate mass elements is a product of the subsequent denotation phase. The fact that the SNe Iax population does not follow a tight brightness-decline relation similar to SNe Ia can then be understood in the framework of variable amounts of mixing during pulsational rebound and variable amounts of 56Ni production during the early subsonic phase
Three dimensional N=4 supersymmetric mechanics with Wu-Yang monopole
DOE Office of Scientific and Technical Information (OSTI.GOV)
Bellucci, Stefano; Krivonos, Sergey; Sutulin, Anton
2010-05-15
We propose Lagrangian and Hamiltonian formulations of a N=4 supersymmetric three-dimensional isospin-carrying particle moving in the non-Abelian field of a Wu-Yang monopole and in some specific scalar potential. This additional potential is completely fixed by N=4 supersymmetry, and in the simplest case of flat metrics it coincides with that which provides the existence of the Runge-Lenz vector for the bosonic subsector. The isospin degrees of freedom are described on the Lagrangian level by bosonic auxiliary variables forming N=4 supermultiplet with additional, also auxiliary, fermions. Being quite general, the constructed systems include such interesting cases as N=4 superconformally invariant systems withmore » Wu-Yang monopole, the particles living in the flat R{sup 3} and in the RxS{sup 2} spaces and interacting with the monopole, and also the particles moving on three-dimensional sphere and pseudosphere with the Wu-Yang monopole sitting in the center. The superfield Lagrangian description of these systems is so simple that one could wonder to see how all couplings and the proper coefficients arise while passing to the component action.« less
Interpersonal Harmony and Conflict for Chinese People: A Yin-Yang Perspective.
Huang, Li-Li
2016-01-01
This article provides an overview on a series of original studies conducted by the author. The aim here is to present the ideas that the author reconstructed, based on the dialectics of harmonization, regarding harmony and conflict embodied in traditional Chinese thought, and to describe how a formal psychological theory/model on interpersonal harmony and conflict was developed based on the Yin-Yang perspective. The paper also details how essential theories on interpersonal harmony and conflict were constructed under this formal model by conducting a qualitative study involving in-depth interviews with 30 adults. Psychological research in Western society has, intriguingly, long been focused more on interpersonal conflict than on interpersonal harmony. By contrast, the author's work started from the viewpoint of a materialist conception of history and dialectics of harmonization in order to reinterpret traditional Chinese thought. Next, a "dynamic model of interpersonal harmony and conflict" was developed, as a formal psychological theory, based on the real-virtual notions in the Yin-Yang perspective. Under this model, interpersonal harmony and conflict can be classified into genuine versus superficial harmony and authentic versus virtual focus conflict, and implicit/hidden conflict is regarded as superficial harmony. Subsequently, the author conducted a series of quantitative studies on interpersonal harmony and conflict within parent-child, supervisor-subordinate, and friend-friend relationships in order to verify the construct validity and the predictive validity of the dynamic model of interpersonal harmony and conflict. The claim presented herein is that Chinese traditional thought and the psychological theory/model based on the Yin-Yang perspective can be combined. Accordingly, by combining qualitative and quantitative empirical research, the relative substantial theory can be developed and the concepts can be validated. Thus, this work represents the
Interpersonal Harmony and Conflict for Chinese People: A Yin–Yang Perspective
Huang, Li-Li
2016-01-01
This article provides an overview on a series of original studies conducted by the author. The aim here is to present the ideas that the author reconstructed, based on the dialectics of harmonization, regarding harmony and conflict embodied in traditional Chinese thought, and to describe how a formal psychological theory/model on interpersonal harmony and conflict was developed based on the Yin–Yang perspective. The paper also details how essential theories on interpersonal harmony and conflict were constructed under this formal model by conducting a qualitative study involving in-depth interviews with 30 adults. Psychological research in Western society has, intriguingly, long been focused more on interpersonal conflict than on interpersonal harmony. By contrast, the author’s work started from the viewpoint of a materialist conception of history and dialectics of harmonization in order to reinterpret traditional Chinese thought. Next, a “dynamic model of interpersonal harmony and conflict” was developed, as a formal psychological theory, based on the real-virtual notions in the Yin–Yang perspective. Under this model, interpersonal harmony and conflict can be classified into genuine versus superficial harmony and authentic versus virtual focus conflict, and implicit/hidden conflict is regarded as superficial harmony. Subsequently, the author conducted a series of quantitative studies on interpersonal harmony and conflict within parent–child, supervisor–subordinate, and friend–friend relationships in order to verify the construct validity and the predictive validity of the dynamic model of interpersonal harmony and conflict. The claim presented herein is that Chinese traditional thought and the psychological theory/model based on the Yin–Yang perspective can be combined. Accordingly, by combining qualitative and quantitative empirical research, the relative substantial theory can be developed and the concepts can be validated. Thus, this work
On spinodal points and Lee-Yang edge singularities
NASA Astrophysics Data System (ADS)
An, X.; Mesterházy, D.; Stephanov, M. A.
2018-03-01
We address a number of outstanding questions associated with the analytic properties of the universal equation of state of the φ4 theory, which describes the critical behavior of the Ising model and ubiquitous critical points of the liquid–gas type. We focus on the relation between spinodal points that limit the domain of metastability for temperatures below the critical temperature, i.e. T < Tc , and Lee-Yang edge singularities that restrict the domain of analyticity around the point of zero magnetic field H for T > Tc . The extended analyticity conjecture (due to Fonseca and Zamolodchikov) posits that, for T < Tc , the Lee-Yang edge singularities are the closest singularities to the real H axis. This has interesting implications, in particular, that the spinodal singularities must lie off the real H axis for d < 4 , in contrast to the commonly known result of the mean-field approximation. We find that the parametric representation of the Ising equation of state obtained in the \\renewcommandε{\\varepsilon} \
Body composition and personality traits in so-Yang type males.
Yoon, Jiwon; Nam, Jiho; Leem, Chae Hun; Kim, Jong Yeol
2017-08-22
The purpose of the present study was to examine the body composition of So-Yang type males according to Sasang constitutional medicine, which is popular in Korea. Different Sasang constitutional types are associated with different muscle distributions, body shapes, and disease susceptibilities. We used the Sasang Personality Questionnaire (SPQ) as a measure of the temperament of each Sasang type. In total, 953 subjects aged over 20 years were recruited in Korea. We collected anthropometric parameters and bioimpedence information from the subjects and administered the SPQ. A logistic regression was conducted to calculate propensity scores. The percentage of skeletal muscle mass in So-Yang (SY) and non-So-Yang (non-SY) males was 45.8 ± 2.7 and 44.2 ± 3.3, respectively, before matching and 45.8 ± 2.6 and 44.9 ± 3.0, respectively, after propensity score matching. The extracellular water (ECW)/intracellular water (ICW) and extracellular water (ECW)/total body water (TBW) ratios and SPQ scores were significantly different between the SY and non-SY types. This study suggested that the SY type may be significantly and independently associated with body composition and could be associated with personality.
Rota-Baxter operators on sl (2,C) and solutions of the classical Yang-Baxter equation
DOE Office of Scientific and Technical Information (OSTI.GOV)
Pei, Jun, E-mail: peitsun@163.com; Bai, Chengming, E-mail: baicm@nankai.edu.cn; Guo, Li, E-mail: liguo@rutgers.edu
2014-02-15
We explicitly determine all Rota-Baxter operators (of weight zero) on sl (2,C) under the Cartan-Weyl basis. For the skew-symmetric operators, we give the corresponding skew-symmetric solutions of the classical Yang-Baxter equation in sl (2,C), confirming the related study by Semenov-Tian-Shansky. In general, these Rota-Baxter operators give a family of solutions of the classical Yang-Baxter equation in the six-dimensional Lie algebra sl (2,C)⋉{sub ad{sup *}} sl (2,C){sup *}. They also give rise to three-dimensional pre-Lie algebras which in turn yield solutions of the classical Yang-Baxter equation in other six-dimensional Lie algebras.
Classical Yang-Baxter equations and quantum integrable systems
NASA Astrophysics Data System (ADS)
Jurčo, Branislav
1989-06-01
Quantum integrable models associated with nondegenerate solutions of classical Yang-Baxter equations related to the simple Lie algebras are investigated. These models are diagonalized for rational and trigonometric solutions in the cases of sl(N)/gl(N)/, o(N) and sp(N) algebras. The analogy with the quantum inverse scattering method is demonstrated.
Scattering amplitudes in $$\\mathcal{N}=2 $$ Maxwell-Einstein and Yang-Mills/Einstein supergravity
DOE Office of Scientific and Technical Information (OSTI.GOV)
Chiodaroli, Marco; Gunaydin, Murat; Johansson, Henrik
We expose a double-copy structure in the scattering amplitudes of the generic Jordan family of N = 2 Maxwell-Einstein and Yang-Mills/Einstein supergravity theories in four and five dimensions. The Maxwell-Einstein supergravity amplitudes are obtained through the color/kinematics duality as a product of two gauge-theory factors; one originating from pure N = 2 super-Yang-Mills theory and the other from the dimensional reduction of a bosonic higher-dimensional pure Yang-Mills theory. We identify a specific symplectic frame in four dimensions for which the on-shell fields and amplitudes from the double-copy construction can be identified with the ones obtained from the supergravity Lagrangian andmore » Feynman-rule computations. The Yang-Mills/Einstein supergravity theories are obtained by gauging a compact subgroup of the isometry group of their Maxwell-Einstein counterparts. For the generic Jordan family this process is identified with the introduction of cubic scalar couplings on the bosonic gauge-theory side, which through the double copy are responsible for the non-abelian vector interactions in the supergravity theory. As a demonstration of the power of this structure, we present explicit computations at treelevel and one loop. Lastly, the double-copy construction allows us to obtain compact expressions for the supergravity superamplitudes, which are naturally organized as polynomials in the gauge coupling constant.« less
Scattering amplitudes in $$\\mathcal{N}=2 $$ Maxwell-Einstein and Yang-Mills/Einstein supergravity
Chiodaroli, Marco; Gunaydin, Murat; Johansson, Henrik; ...
2015-01-15
We expose a double-copy structure in the scattering amplitudes of the generic Jordan family of N = 2 Maxwell-Einstein and Yang-Mills/Einstein supergravity theories in four and five dimensions. The Maxwell-Einstein supergravity amplitudes are obtained through the color/kinematics duality as a product of two gauge-theory factors; one originating from pure N = 2 super-Yang-Mills theory and the other from the dimensional reduction of a bosonic higher-dimensional pure Yang-Mills theory. We identify a specific symplectic frame in four dimensions for which the on-shell fields and amplitudes from the double-copy construction can be identified with the ones obtained from the supergravity Lagrangian andmore » Feynman-rule computations. The Yang-Mills/Einstein supergravity theories are obtained by gauging a compact subgroup of the isometry group of their Maxwell-Einstein counterparts. For the generic Jordan family this process is identified with the introduction of cubic scalar couplings on the bosonic gauge-theory side, which through the double copy are responsible for the non-abelian vector interactions in the supergravity theory. As a demonstration of the power of this structure, we present explicit computations at treelevel and one loop. Lastly, the double-copy construction allows us to obtain compact expressions for the supergravity superamplitudes, which are naturally organized as polynomials in the gauge coupling constant.« less
Yang-Mills condensate as dark energy: A nonperturbative approach
NASA Astrophysics Data System (ADS)
Donà, Pietro; Marcianò, Antonino; Zhang, Yang; Antolini, Claudia
2016-02-01
Models based on the Yang-Mills condensate (YMC) have been advocated for in the literature and claimed as successful candidates for explaining dark energy. Several variations on this simple idea have been considered, the most promising of which are reviewed here. Nevertheless, the previously attained results relied heavily on the perturbative approach to the analysis of the effective Yang-Mills action, which is only adequate in the asymptotically free limit, and were extended into a regime, the infrared limit, in which confinement is expected. We show that if a minimum of the effective Lagrangian in θ =-Fμν aFa μ ν/2 exists, a YMC forms that drives the Universe toward an accelerated de Sitter phase. The details of the models depend weakly on the specific form of the effective Yang-Mills Lagrangian. Using nonperturbative techniques mutated from the functional renormalization-group procedure, we finally show that the minimum in θ of the effective Lagrangian exists. Thus, a YMC can actually take place. The nonperturbative model has properties similar to the ones in the perturbative model. In the early stage of the Universe, the YMC equation of state has an evolution that resembles the radiation component, i.e., wy→1 /3 . However, in the late stage, wy naturally runs to the critical state with wy=-1 , and the Universe transitions from a matter-dominated into a dark energy dominated stage only at latest time, at a redshift whose value depends on the initial conditions that are chosen while solving the dynamical system.
Phase transitions in Yang-Mills theories and their gravity duals
NASA Astrophysics Data System (ADS)
Marsano, Joseph Daniel
This thesis is a study of the thermal phase structure of systems that admit dual gauge theory and string theory descriptions. In a pair of examples, we explore the connection between perturbative Yang-Mills and gravitational thermodynamics which arises from the fact that these descriptions probe different corners of a single phase diagram. The structure that emerges from a detailed study of these isolated regions generally suggests a natural conjecture how they may be connected to one another within the full phase diagram. This permits the identification of interesting phenomena in the gauge and gravity regimes under a continuous change in parameters. We begin by studying the AdS5/CFT 4 system which, when the supergravity description is valid, exhibits a first order Hawking-Page phase transition as a function of temperature from a thermal gas of gravitons to a large black hole. In the perturbative Yang-Mills regime, we find that the free theory exhibits a weakly first order deconfinement transition whose precise nature at small nonzero coupling depends on the result of a nontrivial perturbative computation. It is conjectured that this deconfinement transition is continuously connected in the full phase diagram to the Hawking-Page transition at strong coupling, with the confined phase identified with the graviton gas and the deconfined phase identified with the black hole. We then turn to the study of Gregory-Laflamme (GL) black hole/black string transitions in supergravity and their realization in a setup that admits a dual description via the maximally supersymmetric Yang-Mills theory on T2. The thermodynamics of Yang-Mills theories on low dimensional tori is studied in detail revealing an intricate structure of which the GL transition at strong coupling is a small piece. We are led to conjecture that GL physics is continuously connected to deconfinement in maximally supersymmetric 0 + 1-dimensional gauged matrix quantum mechanics. This identification will then
Nonperturbative finite-temperature Yang-Mills theory
NASA Astrophysics Data System (ADS)
Cyrol, Anton K.; Mitter, Mario; Pawlowski, Jan M.; Strodthoff, Nils
2018-03-01
We present nonperturbative correlation functions in Landau-gauge Yang-Mills theory at finite temperature. The results are obtained from the functional renormalisation group within a self-consistent approximation scheme. In particular, we compute the magnetic and electric components of the gluon propagator, and the three- and four-gluon vertices. We also show the ghost propagator and the ghost-gluon vertex at finite temperature. Our results for the propagators are confronted with lattice simulations and our Debye mass is compared to hard thermal loop perturbation theory.
Yangians and Yang-Baxter R-operators for ortho-symplectic superalgebras
NASA Astrophysics Data System (ADS)
Fuksa, J.; Isaev, A. P.; Karakhanyan, D.; Kirschner, R.
2017-04-01
Yang-Baxter relations symmetric with respect to the ortho-symplectic superalgebras are studied. We start with the formulation of graded algebras and the linear superspace carrying the vector (fundamental) representation of the ortho-symplectic supergroup. On this basis we study the analogy of the Yang-Baxter operators considered earlier for the cases of orthogonal and symplectic symmetries: the vector (fundamental) R-matrix, the L-operator defining the Yangian algebra and its first and second order evaluations. We investigate the condition for L (u) in the case of the truncated expansion in inverse powers of u and give examples of Lie algebra representations obeying these conditions. We construct the R-operator intertwining two superspinor representations and study the fusion of L-operators involving the tensor product of such representations.
Chen Ning Yang, Weak Interactions, and Parity Violation
absolute law of parity conservation had been violated." 2 "Yang overturned Paul ... Dirac's explained that symmetry laws generate the law of conservation. The law of right-left symmetry contributed to the formulation of the law of conservation of parity in 1924. Eventually, this law of conservation was
Yangian Symmetry and Integrability of Planar N=4 Supersymmetric Yang-Mills Theory.
Beisert, Niklas; Garus, Aleksander; Rosso, Matteo
2017-04-07
In this Letter, we establish Yangian symmetry of planar N=4 supersymmetric Yang-Mills theory. We prove that the classical equations of motion of the model close onto themselves under the action of Yangian generators. Moreover, we propose an off-shell extension of our statement, which is equivalent to the invariance of the action and prove that it is exactly satisfied. We assert that our relationship serves as a criterion for integrability in planar gauge theories by explicitly checking that it applies to the integrable Aharony-Bergman-Jafferis-Maldacena theory but not to the nonintegrable N=1 supersymmetric Yang-Mills theory.
Quantum supergroups and solutions of the Yang-Baxter equation
DOE Office of Scientific and Technical Information (OSTI.GOV)
Bracken, A.J.; Gould, M.D.; Zhang, R.B.
1990-05-10
A method is developed for systematically constructing trigonometric and rational solutions of the Yang-Baxter equation using the representation theory of quantum supergroups. New quantum R-matrices are obtained by applying the method to the vector representations of quantum osp(1/2) and gl(m/n).
GL/sub 3/-invariant solutions of the Yang-Baxter equation and associated quantum systems
DOE Office of Scientific and Technical Information (OSTI.GOV)
Kulish, P.P.; Reshetikhin, N.Yu.
1987-05-20
The authors investigate the GL/sub 3/-invariant finite-dimensional solutions of the Yang-Baxter equation acting in the tensor product of two irreducible representations of the GL/sub 3/ group. Relationships obtained for the transfer matrices demonstrate the link between representation theory and the Bethe ansatz in GL/sub 3/-invariant models. Some examples of quantum and classical integrable systems associated with GL/sub 3/-invariant solutions of the Yang-Baxter equation are given.
Intermittency and dynamical Lee-Yang zeros of open quantum systems.
Hickey, James M; Flindt, Christian; Garrahan, Juan P
2014-12-01
We use high-order cumulants to investigate the Lee-Yang zeros of generating functions of dynamical observables in open quantum systems. At long times the generating functions take on a large-deviation form with singularities of the associated cumulant generating functions-or dynamical free energies-signifying phase transitions in the ensemble of dynamical trajectories. We consider a driven three-level system as well as the dissipative Ising model. Both systems exhibit dynamical intermittency in the statistics of quantum jumps. From the short-time behavior of the dynamical Lee-Yang zeros, we identify critical values of the counting field which we attribute to the observed intermittency and dynamical phase coexistence. Furthermore, for the dissipative Ising model we construct a trajectory phase diagram and estimate the value of the transverse field where the stationary state changes from being ferromagnetic (inactive) to paramagnetic (active).
Continuum strong-coupling expansion of Yang-Mills theory: quark confinement and infra-red slavery
NASA Astrophysics Data System (ADS)
Mansfield, Paul
1994-04-01
We solve Schrödinger's equation for the ground-state of four-dimensional Yang-Mills theory as an expansion in inverse powers of the coupling. Expectation values computed with the leading-order approximation are reduced to a calculation in two-dimensional Yang-Mills theory which is known to confine. Consequently the Wilson loop in the four-dimensional theory obeys an area law to leading order and the coupling becomes infinite as the mass scale goes to zero.
Yang Baxter and anisotropic sigma and lambda models, cyclic RG and exact S-matrices
NASA Astrophysics Data System (ADS)
Appadu, Calan; Hollowood, Timothy J.; Price, Dafydd; Thompson, Daniel C.
2017-09-01
Integrable deformation of SU(2) sigma and lambda models are considered at the classical and quantum levels. These are the Yang-Baxter and XXZ-type anisotropic deformations. The XXZ type deformations are UV safe in one regime, while in another regime, like the Yang-Baxter deformations, they exhibit cyclic RG behaviour. The associ-ated affine quantum group symmetry, realized classically at the Poisson bracket level, has q a complex phase in the UV safe regime and q real in the cyclic RG regime, where q is an RG invariant. Based on the symmetries and RG flow we propose exact factorizable S-matrices to describe the scattering of states in the lambda models, from which the sigma models follow by taking a limit and non-abelian T-duality. In the cyclic RG regimes, the S-matrices are periodic functions of rapidity, at large rapidity, and in the Yang-Baxter case violate parity.
[The Yin and Yang movement in the cosmology of Chinese medicine].
Coutinho, Bernardo Diniz; Dulcetti, Pérola Goretti Sichero
2015-01-01
After being developed in the East, based on Taoist cosmology, Chinese medicine has been practiced in the West based on scientific foundations and biomedical paradigms. Some traditional elements of this philosophy were abandoned, such as the theory of Yin and Yang, knowledge that is essential for understanding the health-disease process resulting from the circulation of the body's energy flow. This article studies the movement of the dual elements of Yin and Yang in Chinese medical teaching, seeking to understand how this line of thought developed and how it has contributed towards establishing a system of diagnosis and therapy. The methodology employed was to analyze literature on the subject, based on theoretical references to Taoist thought and traditional Chinese medicine.
A Preliminary Study on the Yang-cheon-cheok (量天尺) in the Late Joseon Dynasty
NASA Astrophysics Data System (ADS)
Kim, Sang Hyuk; Mihn, Byeong-Hee; Lee, Yong Sam
2015-12-01
We investigated the six remaining Yang-cheon-cheoks (量天尺), which were first described in the Veritable Record of King Sukjong (肅宗實錄). These woodblock sundials from Korea are structurally very similar to a Gyupyo (圭表, gnomon) or an altitude sundial and are light, compact, and portable. The front side of a Yang-cheon-cheok has two holes for styluses and several hour-lines. We compared the intervals of the hour-lines from the originating point of the stylus placement on all Yang-cheon-cheoks and found that two of the relics had the same hour-lines using the standard of the unit of 1 chon (寸). These two were actually the same sundial although the physical size was different. In spite of the lack of time accuracy, we hypothesize that various-sized Yang-cheon-cheoks were made and widely distributed throughout the public in the late Joseon Dynasty.
Finite-action solutions of Yang-Mills equations on de Sitter dS4 and anti-de Sitter AdS4 spaces
NASA Astrophysics Data System (ADS)
Ivanova, Tatiana A.; Lechtenfeld, Olaf; Popov, Alexander D.
2017-11-01
We consider pure SU(2) Yang-Mills theory on four-dimensional de Sitter dS4 and anti-de Sitter AdS4 spaces and construct various solutions to the Yang-Mills equations. On de Sitter space we reduce the Yang-Mills equations via an SU(2)-equivariant ansatz to Newtonian mechanics of a particle moving in R^3 under the influence of a quartic potential. Then we describe magnetic and electric-magnetic solutions, both Abelian and non-Abelian, all having finite energy and finite action. A similar reduction on anti-de Sitter space also yields Yang-Mills solutions with finite energy and action. We propose a lower bound for the action on both backgrounds. Employing another metric on AdS4, the SU(2) Yang-Mills equations are reduced to an analytic continuation of the above particle mechanics from R^3 to R^{2,1} . We discuss analytical solutions to these equations, which produce infinite-action configurations. After a Euclidean continuation of dS4 and AdS4 we also present self-dual (instanton-type) Yang-Mills solutions on these backgrounds.
GL/sub 3/-invariant solutions of the Yang-Baxter equation and associated quantum systems
DOE Office of Scientific and Technical Information (OSTI.GOV)
Kulish, P.P.; Reshetikin N.Y.
1986-09-01
GL/sub 3/-invariant, finite-dimensional solutions of the Yang-Baxter equations acting in the tensor product of two irreducible representations of the group GL/sub 3/ are investigated. A number of relations are obtained for the transfer matrices which demonstrate the connection of representation theory and the Bethe Ansatz in GL/sub 3/invariant models. Some of the most interesting quantum and classical integrable systems connected with GL/sub 3/-invariant solutions of the Yang-Baxter equation are presented.
GL/sub 3/-invariant solutions of the Yang-Baxter equation and associated quantum systems
DOE Office of Scientific and Technical Information (OSTI.GOV)
Kulish, P.P.; Reshetikhin, N.Yu.
1986-09-10
GL/sub 3/-invariant, finite-dimensional solutions of the Yang-Baxter equations acting in the tensor product of two irreducible representations of the group GL/sub 3/ are investigated. A number of relations are obtained for the transfer matrices which demonstrate the connection of representation theory and the Bethe Ansatz in GL/sub 3/-invariant models. Some of the most interesting quantum and classical integrable systems connected with GL/sub 3/-invariant solutions of the Yang-Baxter equation are presented.
Yang-Lee zeros, Julia sets, and their singularity spectra
DOE Office of Scientific and Technical Information (OSTI.GOV)
Hu, B.; Lin, B.
1989-05-01
We have studied the global scaling properties of the Julia sets of the Yang-Lee zeros of the s-state Potts model on the diamond hierarchical lattice. The singularity spectrum f(..cap alpha..) and the generalized dimension D/sub q/ are calculated for different s values. General observations are made on their variations.
Vacuum structure and string tension in Yang-Mills dimeron ensembles
NASA Astrophysics Data System (ADS)
Zimmermann, Falk; Forkel, Hilmar; Müller-Preußker, Michael
2012-11-01
We numerically simulate ensembles of SU(2) Yang-Mills dimeron solutions with a statistical weight determined by the classical action and perform a comprehensive analysis of their properties as a function of the bare coupling. In particular, we examine the extent to which these ensembles and their classical gauge interactions capture topological and confinement properties of the Yang-Mills vacuum. This also allows us to put the classic picture of meron-induced quark confinement, with the confinement-deconfinement transition triggered by dimeron dissociation, to stringent tests. In the first part of our analysis we study spacial, topological-charge and color correlations at the level of both the dimerons and their meron constituents. At small to moderate couplings, the dependence of the interactions between the dimerons on their relative color orientations is found to generate a strong attraction (repulsion) between nearest neighbors of opposite (equal) topological charge. Hence, the emerging short- to mid-range order in the gauge-field configurations screens topological charges. With increasing coupling this order weakens rapidly, however, in part because the dimerons gradually dissociate into their less localized meron constituents. Monitoring confinement properties by evaluating Wilson-loop expectation values, we find the growing disorder due to the long-range tails of these progressively liberated merons to generate a finite and (with the coupling) increasing string tension. The short-distance behavior of the static quark-antiquark potential, on the other hand, is dominated by small, “instantonlike” dimerons. String tension, action density and topological susceptibility of the dimeron ensembles in the physical coupling region turn out to be of the order of standard values. Hence, the above results demonstrate without reliance on weak-coupling or low-density approximations that the dissociating dimeron component in the Yang-Mills vacuum can indeed produce a
Critical phenomena in the general spherically symmetric Einstein-Yang-Mills system
NASA Astrophysics Data System (ADS)
Maliborski, Maciej; Rinne, Oliver
2018-02-01
We study critical behavior in gravitational collapse of a general spherically symmetric Yang-Mills field coupled to the Einstein equations. Unlike the magnetic ansatz used in previous numerical work, the general Yang-Mills connection has two degrees of freedom in spherical symmetry. This fact changes the phenomenology of critical collapse dramatically. The magnetic sector features both type I and type II critical collapse, with universal critical solutions. In contrast, in the general system type I disappears and the critical behavior at the threshold between dispersal and black hole formation is always type II. We obtain values of the mass scaling and echoing exponents close to those observed in the magnetic sector, however we find some indications that the critical solution differs from the purely magnetic discretely self-similar attractor and exact self-similarity and universality might be lost. The additional "type III" critical phenomenon in the magnetic sector, where black holes form on both sides of the threshold but the Yang-Mills potential is in different vacuum states and there is a mass gap, also disappears in the general system. We support our dynamical numerical simulations with calculations in linear perturbation theory; for instance, we compute quasi-normal modes of the unstable attractor (the Bartnik-McKinnon soliton) in type I collapse in the magnetic sector.
[Summary of professor YANG Jun's experience for intractable facial paralysis].
Wang, Tao; Li, Zaiyuan; Ge, Tingqiu; Zhang, Man; Yuan, Aihong; Yang, Jun
2017-06-12
Professor YANG Jun 's experience of diagnosis and treatment for intractable facial paralysis is introduced. Professor YANG focuses on the thinking model that combines TCM, western medicine and acupuncture, and adopts the differentiation system that combines disease differentiation, syndrome differentiation and meridian differentiation; he adopts the treatment integrates etiological treatment, overall regulation, symptomatic treatment as well as acupuncture, moxibustion, medication and flash cupping. The acupoints of yangming meridians are mostly selected, and acupoints of governor vessel such as Dazhui (GV 14) and Jinsuo (GV 8) are highly valued. The multiple-needles shallow-penetration-insertion twirling lifting and thrusting technique are mostly adopted to achieve slow and mild acupuncture sensation; in addition, the facial muscles are pulled up with mechanics action. The intensive stimulation with electroacupuncture is recommended at Qianzheng (Extra), Yifeng (TE 17) and Yangbai (GB 14), which is given two or three treatments per week.
Discriminating between two reformulations of SU(3) Yang-Mills theory on a lattice
DOE Office of Scientific and Technical Information (OSTI.GOV)
Shibata, Akihiro; Kondo, Kei-Ichi; Shinohara, Toru
2016-01-22
In order to investigate quark confinement, we give a new reformulation of the SU (N) Yang-Mills theory on a lattice and present the results of the numerical simulations of the SU (3) Yang-Mills theory on a lattice. The numerical simulations include the derivation of the linear potential for static interquark potential, i.e., non-vanishing string tension, in which the “Abelian” dominance and magnetic monopole dominance are established, confirmation of the dual Meissner effect by measuring the chromoelectric flux tube between quark-antiquark pair, the induced magnetic-monopole current, and the type of dual superconductivity, etc.
Perturbative Yang-Mills theory without Faddeev-Popov ghost fields
NASA Astrophysics Data System (ADS)
Huffel, Helmuth; Markovic, Danijel
2018-05-01
A modified Faddeev-Popov path integral density for the quantization of Yang-Mills theory in the Feynman gauge is discussed, where contributions of the Faddeev-Popov ghost fields are replaced by multi-point gauge field interactions. An explicit calculation to O (g2) shows the equivalence of the usual Faddeev-Popov scheme and its modified version.
Yang-Baxter deformations of W2,4 × T1,1 and the associated T-dual models
NASA Astrophysics Data System (ADS)
Sakamoto, Jun-ichi; Yoshida, Kentaroh
2017-08-01
Recently, for principal chiral models and symmetric coset sigma models, Hoare and Tseytlin proposed an interesting conjecture that the Yang-Baxter deformations with the homogeneous classical Yang-Baxter equation are equivalent to non-abelian T-dualities with topological terms. It is significant to examine this conjecture for non-symmetric (i.e., non-integrable) cases. Such an example is the W2,4 ×T 1 , 1 background. In this note, we study Yang-Baxter deformations of type IIB string theory defined on W2,4 ×T 1 , 1 and the associated T-dual models, and show that this conjecture is valid even for this case. Our result indicates that the conjecture would be valid beyond integrability.
Koopman-von Neumann formulation of classical Yang-Mills theories: I
NASA Astrophysics Data System (ADS)
Carta, P.; Gozzi, E.; Mauro, D.
2006-03-01
In this paper we present the Koopman-von Neumann (KvN) formulation of classical non-Abelian gauge field theories. In particular we shall explore the functional (or classical path integral) counterpart of the KvN method. In the quantum path integral quantization of Yang-Mills theories concepts like gauge-fixing and Faddeev-Popov determinant appear in a quite natural way. We will prove that these same objects are needed also in this classical path integral formulation for Yang-Mills theories. We shall also explore the classical path integral counterpart of the BFV formalism and build all the associated universal and gauge charges. These last are quite different from the analog quantum ones and we shall show the relation between the two. This paper lays the foundation of this formalism which, due to the many auxiliary fields present, is rather heavy. Applications to specific topics outlined in the paper will appear in later publications.
Supersymmetric tools in Yang-Mills theories at strong coupling: The beginning of a long journey
NASA Astrophysics Data System (ADS)
Shifman, Mikhail
2018-04-01
Development of holomorphy-based methods in super-Yang-Mills theories started in the early 1980s and lead to a number of breakthrough results. I review some results in which I participated. The discovery of Seiberg’s duality and the Seiberg-Witten solution of 𝒩 = 2 Yang-Mills were the milestones in the long journey of which, I assume, much will be said in other talks. I will focus on the discovery (2003) of non-Abelian vortex strings with various degrees of supersymmetry, supported in some four-dimensional Yang-Mills theories and some intriguing implications of this discovery. One of the recent results is the observation of a soliton string in the bulk 𝒩 = 2 theory with the U(2) gauge group and four flavors, which can become critical in a certain limit. This is the case of a “reverse holography,” with a very transparent physical meaning.
N =2 super Yang-Mills theory in projective superspace
NASA Astrophysics Data System (ADS)
Davgadorj, Ariunzul; von Unge, Rikard
2018-05-01
We find a formulation of N =2 supersymmetric Yang-Mills theory in projective superspace. In particular we find an expression for the field strength in terms of an unconstrained prepotential which is desirable when quantizing the theory. We use this to write the action in terms of the prepotential and show that it reduces to the known result in the Abelian limit.
Homogeneous Yang-Baxter deformations as generalized diffeomorphisms
NASA Astrophysics Data System (ADS)
Sakamoto, Jun-ichi; Sakatani, Yuho; Yoshida, Kentaroh
2017-10-01
Yang-Baxter (YB) deformations of string sigma model provide deformed target spaces. We propose that homogeneous YB deformations always lead to a certain class of β-twisted backgrounds and represent the bosonic part of the supergravity fields in terms of the classical r-matrix associated with the YB deformation. We then show that various β-twisted backgrounds can be realized by considering generalized diffeomorphisms in the undeformed background. Our result extends the notable relation between the YB deformations and (non-commuting) TsT transformations. We also discuss more general deformations beyond the YB deformations.
Classical r matrix of the su(2 vertical bar 2) super Yang-Mills spin chain
DOE Office of Scientific and Technical Information (OSTI.GOV)
Torrielli, Alessandro
2007-05-15
In this note we straightforwardly derive and make use of the quantum R matrix for the su(2 vertical bar 2) super Yang-Mills spin chain in the manifest su(1 vertical bar 2)-invariant formulation, which solves the standard quantum Yang-Baxter equation, in order to obtain the correspondent (undressed) classical r matrix from the first order expansion in the 'deformation' parameter 2{pi}/{radical}({lambda}) and check that this last solves the standard classical Yang-Baxter equation. We analyze its bialgebra structure, its dependence on the spectral parameters, and its pole structure. We notice that it still preserves an su(1 vertical bar 2) subalgebra, thereby admitting anmore » expression in terms of a combination of projectors, which spans only a subspace of su(1 vertical bar 2)xsu(1 vertical bar 2). We study the residue at its simple pole at the origin and comment on the applicability of the classical Belavin-Drinfeld type of analysis.« less
Yang-Baxter maps, discrete integrable equations and quantum groups
NASA Astrophysics Data System (ADS)
Bazhanov, Vladimir V.; Sergeev, Sergey M.
2018-01-01
For every quantized Lie algebra there exists a map from the tensor square of the algebra to itself, which by construction satisfies the set-theoretic Yang-Baxter equation. This map allows one to define an integrable discrete quantum evolution system on quadrilateral lattices, where local degrees of freedom (dynamical variables) take values in a tensor power of the quantized Lie algebra. The corresponding equations of motion admit the zero curvature representation. The commuting Integrals of Motion are defined in the standard way via the Quantum Inverse Problem Method, utilizing Baxter's famous commuting transfer matrix approach. All elements of the above construction have a meaningful quasi-classical limit. As a result one obtains an integrable discrete Hamiltonian evolution system, where the local equation of motion are determined by a classical Yang-Baxter map and the action functional is determined by the quasi-classical asymptotics of the universal R-matrix of the underlying quantum algebra. In this paper we present detailed considerations of the above scheme on the example of the algebra Uq (sl (2)) leading to discrete Liouville equations, however the approach is rather general and can be applied to any quantized Lie algebra.
Berry phase and entanglement of three qubits in a new Yang-Baxter system
DOE Office of Scientific and Technical Information (OSTI.GOV)
Hu Taotao; Xue Kang; Wu Chunfeng
2009-08-15
In this paper we construct a new 8x8M matrix from the 4x4M matrix, where M/M is the image of the braid group representation. The 8x8M matrix and the 4x4M matrix both satisfy extraspecial 2-group algebra relations. By Yang-Baxteration approach, we derive a unitary R({theta},{phi}) matrix from the M matrix with parameters {phi} and {theta}. Three-qubit entangled states can be generated by using the R({theta},{phi}) matrix. A Hamiltonian for three qubits is constructed from the unitary R({theta},{phi}) matrix. We then study the entanglement and Berry phase of the Yang-Baxter system.
A Yang-Mills field on the extremal Reissner-Nordström black hole
NASA Astrophysics Data System (ADS)
Bizoń, Piotr; Kahl, Michał
2016-09-01
We consider a spherically symmetric (magnetic) SU(2) Yang-Mills field propagating on the exterior of the extremal Reissner-Nordström black hole. Taking advantage of the conformal symmetry, we reduce the problem to the study of the Yang-Mills equation in a geodesically complete spacetime with two asymptotically flat ends. We prove the existence of infinitely many static solutions (two of which are found in closed form) and determine the spectrum of their linear perturbations and quasinormal modes. Finally, using the hyperboloidal approach to the initial value problem, we describe the process of relaxation to the static endstates of evolution, both stable (for generic initial data) and unstable (for codimension-one initial data).
DOE Office of Scientific and Technical Information (OSTI.GOV)
Dancer, K. A.; Isac, P. S.; Links, J.
2006-10-15
Quantum doubles of finite group algebras form a class of quasitriangular Hopf algebras that algebraically solve the Yang-Baxter equation. Each representation of the quantum double then gives a matrix solution of the Yang-Baxter equation. Such solutions do not depend on a spectral parameter, and to date there has been little investigation into extending these solutions such that they do depend on a spectral parameter. Here we first explicitly construct the matrix elements of the generators for all irreducible representations of quantum doubles of the dihedral groups D{sub n}. These results may be used to determine constant solutions of the Yang-Baxtermore » equation. We then discuss Baxterization ansaetze to obtain solutions of the Yang-Baxter equation with a spectral parameter and give several examples, including a new 21-vertex model. We also describe this approach in terms of minimal-dimensional representations of the quantum doubles of the alternating group A{sub 4} and the symmetric group S{sub 4}.« less
NASA Astrophysics Data System (ADS)
Kawabata, Kiyoshi
2018-01-01
We have established an iterative scheme to calculate with 15-digit accuracy the numerical values of Ambartsumian-Chandrasekhar's H-functions for anisotropic scattering characterized by the four-term phase function: the method incorporates some advantageous features of the iterative procedure of Kawabata (Astrophys. Space Sci. 358:32, 2015) and the double-exponential integration formula (DE-formula) of Takahashi and Mori (Publ. Res. Inst. Math. Sci. Kyoto Univ. 9:721, 1974), which proved highly effective in Kawabata (Astrophys. Space Sci. 361:373, 2016). Actual calculations of the H-functions have been carried out employing 27 selected cases of the phase function, 56 values of the single scattering albedo π0, and 36 values of an angular variable μ(= cosθ), with θ being the zenith angle specifying the direction of incidence and/or emergence of radiation. Partial results obtained for conservative isotropic scattering, Rayleigh scattering, and anisotropic scattering due to a full four-term phase function are presented. They indicate that it is important to simultaneously verify accuracy of the numerical values of the H-functions for μ<0.05, the domain often neglected in tabulation. As a sample application of the isotropic scattering H-function, an attempt is made in Appendix to simulate by iteratively solving the Ambartsumian equation the values of the plane and spherical albedos of a semi-infinite, homogeneous atmosphere calculated by Rogovtsov and Borovik (J. Quant. Spectrosc. Radiat. Transf. 183:128, 2016), who employed their analytical representations for these quantities and the single-term and two-term Henyey-Greenstein phase functions of appreciably high degrees of anisotropy. While our results are in satisfactory agreement with theirs, our procedure is in need of a faster algorithm to routinely deal with problems involving highly anisotropic phase functions giving rise to near-conservative scattering.
NASA Astrophysics Data System (ADS)
Hendi, Seyed Hossein; Momennia, Mehrab
2018-02-01
Motivated by the interesting non-abelian gauge field, in this paper, we look for the analytical solutions of Yang-Mills theory in the context of gravity's rainbow. Regarding the trace of quantum gravity in black hole thermodynamics, we examine the first law of thermodynamics and also thermal stability in the canonical ensemble. We show that although the rainbow functions and Yang-Mills charge modify the solutions, the first law of thermodynamics is still valid. Based on the phenomenological similarities between the adS black holes and van der Waals liquid/gas systems, we study the critical behavior of the Yang-Mills black holes in the extended phase space thermodynamics. We also investigate the effects of various parameters on thermal instability as well as critical properties by using appropriate figures.
NASA Astrophysics Data System (ADS)
Gußmann, Alexander
2017-03-01
The existence of the classical black hole solutions of the Einstein-Yang-Mills-Higgs equations with non-Abelian Yang-Mills-Higgs hair implies that not all classical stationary magnetically charged black holes can be uniquely described by their asymptotic characteristics. In fact, in a certain domain of parameters, there exist different spherically-symmetric, non-rotating and asymptotically-flat classical black hole solutions of the Einstein-Yang-Mills-Higgs equations which have the same ADM mass and the same magnetic charge but significantly different geometries in the near-horizon regions. (These are black hole solutions which are described by a Reissner-Nordström metric on the one hand and the black hole solutions with non-Abelian Yang-Mills-Higgs hair which are described by a metric which is not of Reissner-Nordström form on the other hand). One can experimentally distinguish such black holes with the same asymptotic characteristics but different near-horizon geometries classically by probing the near-horizon regions of the black holes. We argue that one way to probe the near-horizon region of a black hole which allows one to distinguish magnetically charged black holes with the same asymptotic characteristics but different near-horizon geometries is by classical scattering of waves. Using the example of a minimally-coupled massless probe scalar field scattered by magnetically charged black holes which can be obtained as solutions of the Einstein-Yang-Mills-Higgs equations with a Higgs triplet and gauge group SU(2) in the limit of an infinite Higgs self-coupling constant we show how, in this case, the scattering cross sections differ for the magnetically charged black holes with different near-horizon geometries but the same asymptotic characteristics. We find in particular that the characteristic glory peaks in the cross sections are located at different scattering angles.
Non-Commutative Rational Yang-Baxter Maps
NASA Astrophysics Data System (ADS)
Doliwa, Adam
2014-03-01
Starting from multidimensional consistency of non-commutative lattice-modified Gel'fand-Dikii systems, we present the corresponding solutions of the functional (set-theoretic) Yang-Baxter equation, which are non-commutative versions of the maps arising from geometric crystals. Our approach works under additional condition of centrality of certain products of non-commuting variables. Then we apply such a restriction on the level of the Gel'fand-Dikii systems what allows to obtain non-autonomous (but with central non-autonomous factors) versions of the equations. In particular, we recover known non-commutative version of Hirota's lattice sine-Gordon equation, and we present an integrable non-commutative and non-autonomous lattice modified Boussinesq equation.
Zhang, Ying; Chen, Ze-qi; Zhong, Guang-wei
2008-07-01
To explore the pathogenic mechanism of liver-yang hyperactivity type of hypertension and to observe the effects of Pinggan Qianyang Formula (PGQYF), a compound of traditional Chinese herbals for calming the liver and suppressing yang, so as to provide experimental evidence for new marker proteins of drug therapy. A rat model of liver-yang hyperactivity was prepared with spontaneous hypertensive rats (SHRs) by administration of Aconiti Praeparatae Decoction. Adrenal proteins were separated by 2D gel electrophoresis (2-DE). The differentially expressed proteins were identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) and database analysis. The rat model of liver-yang hyperactivity was successfully reproduced, and the PGQYF could decrease the grades of irritability, conjunctival congestion and systolic blood pressure of the rats (P<0.05, P<0.01). After analysis, twelve obviously differentially expressed proteins were found, eight of which were identified. The expression levels of isocitrate dehydrogenase and steroidogenic acute regulatory protein in the untreated group were up-regulated as compared with those in the normal control group, and down-regulated in the treatment group. The expression levels of ferritin light chain, elongation factor Tu, Rho GDP disassociation inhibitor 1, flavin reductase and basic transcription factor 3 in the untreated group were down-regulated as compared with those in the normal control group, and up-regulated in the treatment group. Differentially expressed adrenal proteins in SHRs with live-yang hyperactivity are successfully identified. This approach may lay a foundation for the further investigation of pathogenic mechanisms in hypertension with liver-yang hyperactivity and the mechanisms of PGQYF treatment.
Dark energy fingerprints in the nonminimal Wu-Yang wormhole structure
NASA Astrophysics Data System (ADS)
Balakin, Alexander B.; Zayats, Alexei E.
2014-08-01
We discuss new exact solutions to nonminimally extended Einstein-Yang-Mills equations describing spherically symmetric static wormholes supported by the gauge field of the Wu-Yang type in a dark energy environment. We focus on the analysis of three types of exact solutions to the gravitational field equations. Solutions of the first type relate to the model, in which the dark energy is anisotropic; i.e., the radial and tangential pressures do not coincide. Solutions of the second type correspond to the isotropic pressure tensor; in particular, we discuss the exact solution, for which the dark energy is characterized by the equation of state for a string gas. Solutions of the third type describe the dark energy model with constant pressure and energy density. For the solutions of the third type, we consider in detail the problem of horizons and find constraints for the parameters of nonminimal coupling and for the constitutive parameters of the dark energy equation of state, which guarantee that the nonminimal wormholes are traversable.
Callan-Symanzik equations for infrared Yang-Mills theory
NASA Astrophysics Data System (ADS)
Weber, Axel; Dall'Olio, Pietro
2017-12-01
Dyson-Schwinger equations have been successful in determining the correlation functions in Yang-Mills theory in the Landau gauge, in the infrared regime. We argue that similar results can be obtained, in a technically simpler way, with Callan-Symanzik renormalization group equations. We present generalizations of the infrared safe renormalization scheme proposed by Tissier and Wschebor in 2011, and show how the renormalization scheme dependence can be used to improve the matching to the existing lattice data for the gluon and ghost propagators.
Research on Remote Sensing recognition features of Yuan Yang Terraces in Yunnan Province (China)
NASA Astrophysics Data System (ADS)
Xiang, Jie; Chen, Jianping; Lai, ZiLi; Yang, Wei
2016-04-01
Yuan Yang terraces is one of the most famous terraces in China, and it was successfully listed in the world heritage list at the 37th world heritage convention. On the one hand, Yuan Yang terraces retain more soil and water, to reduce both hydrological connectivity and erosion, and to support irrigation. On the other hand, It has the important tourism value, bring the huge revenue to local residents. In order to protect and make use of Yuan Yang terraces better, This study analyzed the spatial distribution and spectral characteristics of terraces:(1) Through visual interpretation, the study recognized the terraces based on the spatial adjusted remote sensing image (2010 Geoeye-1 with resolution of 1m/pix), and extracted topographic feature (elevation, slope, aspect, etc.) based on the digital elevation model with resolution of 20m/pix. The terraces cover a total area of about 11.58Km2, accounted for 24.4% of the whole study area. The terraces appear at range from 1400m to 1800m in elevation, 10°to 20°in slope, northwest to northeast in aspect; (2) Using the method of weight of evidence, this study assessed the importance of different topographic feature. The results show that the sort of importance: elevation>slope>aspect; (3) The study counted the Normalized Difference Vegetation Index (NDVI) changes of terraces throughout the year, based on the landsat-5 image with resolution of 30m/pix. The results show that the changes of terraces' NDVI are bigger than other stuff (e.g. forest, road, house, etc.). Those work made a good preparations for establishing the dynamic remote sensing monitoring system of Yuan Yang terraces.
S-duality in SU(3) Yang-Mills theory with non-abelian unbroken gauge group
NASA Astrophysics Data System (ADS)
Schroers, B. J.; Bais, F. A.
1998-12-01
It is observed that the magnetic charges of classical monopole solutions in Yang-Mills-Higgs theory with non-abelian unbroken gauge group H are in one-to-one correspondence with coherent states of a dual or magnetic group H˜. In the spirit of the Goddard-Nuyts-Olive conjecture this observation is interpreted as evidence for a hidden magnetic symmetry of Yang-Mills theory. SU(3) Yang-Mills-Higgs theory with unbroken gauge group U(2) is studied in detail. The action of the magnetic group on semi-classical states is given explicitly. Investigations of dyonic excitations show that electric and magnetic symmetry are never manifest at the same time: Non-abelian magnetic charge obstructs the realisation of electric symmetry and vice-versa. On the basis of this fact the charge sectors in the theory are classified and their fusion rules are discussed. Non-abelian electric-magnetic duality is formulated as a map between charge sectors. Coherent states obey particularly simple fusion rules, and in the set of coherent states S-duality can be formulated as an SL(2, Z) mapping between sectors which leaves the fusion rules invariant.
Yang-Baxter σ-model with WZNW term as E-model
NASA Astrophysics Data System (ADS)
Klimčík, Ctirad
2017-09-01
It turns out that many integrable σ-models on group manifolds belong to the class of the so-called E-models which are relevant in the context of the Poisson-Lie T-duality. We show that this is the case also for the Yang-Baxter σ-model with WZNW term introduced by Delduc, Magro and Vicedo in [5].
An Approach for Expanding Triterpenoid Complexity via Divergent Norrish-Yang Photocyclization
Ignatenko, Vasily A.; Tochtrop, Gregory P.
2013-01-01
Triterpenoids comprise a very diverse family of polycyclic molecules that is well-known to possess a myriad of medicinal properties. Therefore, triterpenoids constitute an attractive target for medicinal chemistry and diversity-oriented synthesis. Photochemical transformations provide a promising tool for the rapid, green and inexpensive generation of skeletal diversity in the construction of natural product-like libraries. With this in mind, we have developed a diversity-oriented strategy, whereby the parent triterpenoids bryonolic acid and lanosterol are converted to the pseudo-symmetrical polyketones by sequential allylic oxidation and oxidative cleavage of the bridging double bond at the B/C-ring fusion. The resultant polyketones were hypothesized to undergo divergent Norrish-Yang cyclization to produce unique 6/4/8-fused triterpenoid analogs. The subtle differences between parent triterpenoids led to dramatically different spatial arrangements of reactive functionalities. This finding was rationalized through conformational analysis to explain unanticipated photoinduced pinacolization, as well as the regio- and stereochemical outcome of the desired Norrish-Yang cyclization. PMID:23544445
Cao, H; Wang, S T; Wu, L Y; Wang, X T; Jiang, A P
2001-06-01
To explore the pharmacodynamic mechanism of Tianxiong (Aconitum carmichaeli) in tonifying the kidney and supporting Yang, so as to provide evidences for further development of new drugs treating Yang-eficiency of the kidney. Observing parameters such as visceral index, survival time of low-temperature swimming for hydrocortisone-induced Yang-deficiency model mouse and testis-removed kidney-deficiency model rat. The decoction of processed Tianxiong could strengthen the antifatigual ability and prolong the survival time of low-temperature swimming for mice, and promote immunization in rats. Tianxiong is able to reinforce the kidney Yang, which reconforms the conclusion of "replenishing the fire of vital gate and the Qi of kidney" recorded in Chinese historical literature and proved by overseas clinical practice.
Kiyang-yang, a West-African Postwar Idiom of Distress
Reis, Ria
2010-01-01
In 1984, a healing cult for young barren women in southern Guinea Bissau developed into a movement, Kiyang-yang, that shook society to its foundations and had national repercussions. “Idiom of distress” is used here as a heuristic tool to understand how Kiyang-yang was able to link war and post-war-related traumatic stress and suffering on both individual and group levels. An individual experience born from a traumatic origin may be generalized into an idiom that diverse sectors of society could embrace for a range of related reasons. We argue that, for an idiom to be understood and appropriated by others, there has to be resonance at the level of symbolic language and shared experiences as well as at the level of the culturally mediated contingent emotions it communicates. We also argue that through its symbolic references to structural causes of suffering, an idiom of distress entails a danger for those in power. It can continue to exist only if its etiology is not exposed or the social suffering it articulates is not eliminated. We finally argue that idioms of distress are not to be understood as discrete diagnostic categories or as monodimensional expressions of “trauma” that can be addressed. PMID:20422270
Dirichlet to Neumann operator for Abelian Yang-Mills gauge fields
NASA Astrophysics Data System (ADS)
Díaz-Marín, Homero G.
We consider the Dirichlet to Neumann operator for Abelian Yang-Mills boundary conditions. The aim is constructing a complex structure for the symplectic space of boundary conditions of Euler-Lagrange solutions modulo gauge for space-time manifolds with smooth boundary. Thus we prepare a suitable scenario for geometric quantization within the reduced symplectic space of boundary conditions of Abelian gauge fields.
Nan, Yang; Zhou, Xiaohang; Liu, Qi; Zhang, Aihua; Guan, Yu; Lin, Shanhua; Kong, Ling; Han, Ying; Wang, Xijun
2016-07-15
Kidney yang deficiency syndrome, a diagnostic pattern in Chinese medicine, is similar with clinical features of the glucocorticoid withdrawal syndrome. The aim of this present study was to explore low molecular mass differentiating metabolites between control group and model group of kidney yang deficiency rats induced with corticosterone as well as the therapeutic effect of Shen Qi Pill, a classic traditional Chinese medicine formula for treating Kidney yang deficiency syndrome in China. This study utilized ultra-performance liquid chromatography coupled with electrospray ionization synapt quadrupole time-of-flight high definition mass spectrometry (UPLC/ESI-SYNAPT-QTOF-HDMS) to identify the underlying biomarkers for clarifying mechanism of Shen Qi Pill in treating Kidney yang deficiency syndrome based on metabolite profiling of the serum samples and in conjunction with multivariate and pathway analysis. Meanwhile, blood biochemistry assay and histopathology were examined to identify specific changes in the model group rats. Distinct changes in the pattern of metabolites were observed by UPLC-HDMS. The changes in metabolic profiling were restored to their baseline values after treatment with Shen Qi Pill according to the combined with a principal component analysis (PCA) score plots. Altogether, the current metabolomics approach based on UPLC-HDMS and orthogonal projection to latent structures discriminate analysis (OPLS-DA) demonstrated 27 ions (18 in the negative mode, 9 in the positive mode, 17 ions restored by Shen Qi Pill). These results indicated that effectiveness of Shen Qi Pill in Kidney yang deficiency syndrome rats induced a substantial change in the metabolic profiles by regulating the biomarkers and adjusting the metabolic disorder. It suggested that the metabolomics approach was a powerful approach for elucidation of pathologic changes of Chinese medicine syndrome and action mechanisms of traditional Chinese medicine. Copyright © 2015 Elsevier B
A THEOREM OF BOURGIN-YANG TYPE FOR \\mathbb{Z}_p^n-ACTION
NASA Astrophysics Data System (ADS)
Volovikov, A. Yu
1993-02-01
A theorem of Bourgin-Yang type is proved for maps of spaces with \\mathbb{Z}_p^n-action into manifolds. The results are applied to the problem of Knaster for maps of spheres into the line and the plane.Bibliography: 44 titles.
Non-Abelian sigma models from Yang-Mills theory compactified on a circle
NASA Astrophysics Data System (ADS)
Ivanova, Tatiana A.; Lechtenfeld, Olaf; Popov, Alexander D.
2018-06-01
We consider SU(N) Yang-Mills theory on R 2 , 1 ×S1, where S1 is a spatial circle. In the infrared limit of a small-circle radius the Yang-Mills action reduces to the action of a sigma model on R 2 , 1 whose target space is a 2 (N - 1)-dimensional torus modulo the Weyl-group action. We argue that there is freedom in the choice of the framing of the gauge bundles, which leads to more general options. In particular, we show that this low-energy limit can give rise to a target space SU (N) ×SU (N) /ZN. The latter is the direct product of SU(N) and its Langlands dual SU (N) /ZN, and it contains the above-mentioned torus as its maximal Abelian subgroup. An analogous result is obtained for any non-Abelian gauge group.
BRST quantization of Yang-Mills theory: A purely Hamiltonian approach on Fock space
NASA Astrophysics Data System (ADS)
Öttinger, Hans Christian
2018-04-01
We develop the basic ideas and equations for the BRST quantization of Yang-Mills theories in an explicit Hamiltonian approach, without any reference to the Lagrangian approach at any stage of the development. We present a new representation of ghost fields that combines desirable self-adjointness properties with canonical anticommutation relations for ghost creation and annihilation operators, thus enabling us to characterize the physical states on a well-defined Fock space. The Hamiltonian is constructed by piecing together simple BRST invariant operators to obtain a minimal invariant extension of the free theory. It is verified that the evolution equations implied by the resulting minimal Hamiltonian provide a quantum version of the classical Yang-Mills equations. The modifications and requirements for the inclusion of matter are discussed in detail.
Su, Yi-Chang; Chen, Li-Li; Lin, Jun-Dai; Lin, Jui-Shan; Huang, Yi-Chia; Lai, Jim-Shoung
2008-12-01
Assessing an individual's level of Yang deficiency (Yang-Xu) by its manifestations is a frequent issue in traditional Chinese medicine (TCM) clinical trials. To this end, an objective, reliable and rigorous diagnostic tool is required. This study aimed to develop a first final version of the Yang-Xu Constitution Questionnaire. We conducted 3 steps to develop such an objective measurement tool: 1) the research team was formed and a panel of 26 experts was selected for the Delphi process; 2) items for the questionnaire were generated by literature review and a Delphi process; items were reworded into colloquial questions; face and content validity of the items were evaluated through a Delphi process again; 3) the difficulty of the questionnaire was evaluated in a pilot study with 81 subjects aged 20-60 years. The literature review retrieved 35 relevant items which matched the definition of 'constitution' and 'Yang-Xu'. After a first Delphi process, 22 items were retained and translated into colloquial questions. According to the second part of the Delphi process, the content validity index of each of the 22 questions ranged between 0.85-1. These 22 questions were evaluated by 81 subjects, 2 questions that were hard to tell the difference were combined; 3 questions were modified after the research team had discussed the participants' feedback. Finally, the questionnaire was established with 21 questions. This first final version of a questionnaire to assess Yang-Xu constitution with considerable face and content validity may serve as a basis to develop an advanced Yang-Xu questionnaire. 2008 S. Karger AG, Basel.
A YinYang bipolar fuzzy cognitive TOPSIS method to bipolar disorder diagnosis.
Han, Ying; Lu, Zhenyu; Du, Zhenguang; Luo, Qi; Chen, Sheng
2018-05-01
Bipolar disorder is often mis-diagnosed as unipolar depression in the clinical diagnosis. The main reason is that, different from other diseases, bipolarity is the norm rather than exception in bipolar disorder diagnosis. YinYang bipolar fuzzy set captures bipolarity and has been successfully used to construct a unified inference mathematical modeling method to bipolar disorder clinical diagnosis. Nevertheless, symptoms and their interrelationships are not considered in the existing method, circumventing its ability to describe complexity of bipolar disorder. Thus, in this paper, a YinYang bipolar fuzzy multi-criteria group decision making method to bipolar disorder clinical diagnosis is developed. Comparing with the existing method, the new one is more comprehensive. The merits of the new method are listed as follows: First of all, multi-criteria group decision making method is introduced into bipolar disorder diagnosis for considering different symptoms and multiple doctors' opinions. Secondly, the discreet diagnosis principle is adopted by the revised TOPSIS method. Last but not the least, YinYang bipolar fuzzy cognitive map is provided for the understanding of interrelations among symptoms. The illustrated case demonstrates the feasibility, validity, and necessity of the theoretical results obtained. Moreover, the comparison analysis demonstrates that the diagnosis result is more accurate, when interrelations about symptoms are considered in the proposed method. In a conclusion, the main contribution of this paper is to provide a comprehensive mathematical approach to improve the accuracy of bipolar disorder clinical diagnosis, in which both bipolarity and complexity are considered. Copyright © 2018 Elsevier B.V. All rights reserved.
Multiscale Monte Carlo equilibration: Pure Yang-Mills theory
Endres, Michael G.; Brower, Richard C.; Orginos, Kostas; ...
2015-12-29
In this study, we present a multiscale thermalization algorithm for lattice gauge theory, which enables efficient parallel generation of uncorrelated gauge field configurations. The algorithm combines standard Monte Carlo techniques with ideas drawn from real space renormalization group and multigrid methods. We demonstrate the viability of the algorithm for pure Yang-Mills gauge theory for both heat bath and hybrid Monte Carlo evolution, and show that it ameliorates the problem of topological freezing up to controllable lattice spacing artifacts.
NASA Astrophysics Data System (ADS)
Chakraborty, Somdeb; Roy, Shibaji
2012-02-01
A particular decoupling limit of the nonextremal (D1, D3) brane bound state system of type IIB string theory is known to give the gravity dual of space-space noncommutative Yang-Mills theory at finite temperature. We use a string probe in this background to compute the jet quenching parameter in a strongly coupled plasma of hot noncommutative Yang-Mills theory in (3+1) dimensions from gauge/gravity duality. We give expressions for the jet quenching parameter for both small and large noncommutativity. For small noncommutativity, we find that the value of the jet quenching parameter gets reduced from its commutative value. The reduction is enhanced with temperature as T7 for fixed noncommutativity and fixed ’t Hooft coupling. We also give an estimate of the correction due to noncommutativity at the present collider energies like in RHIC or in LHC and find it too small to be detected. We further generalize the results for noncommutative Yang-Mills theories in diverse dimensions.
FLRW Cosmology from Yang-Mills Gravity
NASA Astrophysics Data System (ADS)
Katz, Daniel
2013-04-01
We extend to basic cosmology the subject of Yang-Mills gravity - a theory of gravity based on local translational gauge invariance in flat spacetime. It has been shown that this particular gauge invariance leads to tensor factors in the macroscopic limit of the equations of motion of particles which plays the same role as the metric tensor of General Relativity. The assumption that this ``effective metric" tensor takes on the standard FLRW form is our starting point. Equations analogous to the Friedman equations are derived and then solved in closed form for the three special cases of a universe dominated by 1) matter, 2) radiation, and 3) dark energy. We find that the solutions for the scale factor are similar to, but distinct from, those found in the corresponding GR based treatment.
Experiments on Frequency Dependence of the Deflection of Light in Yang-Mills Gravity
NASA Astrophysics Data System (ADS)
Hao, Yun; Zhu, Yiyi; Hsu, Jong-Ping
2018-01-01
In Yang-Mills gravity based on flat space-time, the eikonal equation for a light ray is derived from the modified Maxwell's wave equations in the geometric-optics limit. One obtains a Hamilton-Jacobi type equation, GLµv∂µΨ∂vΨ = 0 with an effective Riemannian metric tensor GLµv. According to Yang-Mills gravity, light rays (and macroscopic objects) move as if they were in an effective curved space-time with a metric tensor. The deflection angle of a light ray by the sun is about 1.53″ for experiments with optical frequencies ≈ 1014Hz. It is roughly 12% smaller than the usual value 1.75″. However, the experimental data in the past 100 years for the deflection of light by the sun in optical frequencies have uncertainties of (10-20)% due to large systematic errors. If one does not take the geometric-optics limit, one has the equation, GLµv[∂µΨ∂vΨcosΨ+ (∂µ∂vΨ)sinΨ] = 0, which suggests that the deflection angle could be frequency-dependent, according to Yang-Mills gravity. Nowadays, one has very accurate data in the radio frequencies ≈ 109Hz with uncertainties less than 0.1%. Thus, one can test this suggestion by using frequencies ≈ 1012 Hz, which could have a small uncertainty 0.1% due to the absence of systematic errors in the very long baseline interferometry.
New perspectives on an old problem: The bending of light in Yang-Mills gravity
NASA Astrophysics Data System (ADS)
Cottrell, Kazuo Ota; Hsu, Jong-Ping
Yang-Mills gravity with electromagnetism predicts, in the geometric optics limit, a value for the deflection of light by the sun which agrees closely with the reanalysis of Eddington's 1919 optical measurements done in 1979. Einstein's General Theory of Relativity, on the other hand, agrees very closely with measurements of the deflection of electromagnetic waves made in the range of radio frequencies. Since both General Relativity and Yang-Mills gravity with electromagnetism in the geometric optics limit make predictions for the optical region which fall within experimental uncertainty, it becomes important to consider the possibility of the existence of a frequency dependence in the measurement results for the deflection of light, in order to determine which theory more closely describes nature...
Yang-Baxter deformations of supercoset sigma models with ℤ4m grading
NASA Astrophysics Data System (ADS)
Ke, San-Min; Yang, Wen-Li; Jang, Ke-Xia; Wang, Chun; Shuai, Xue-Min; Wang, Zhan-Yun; Shi, Gang
2017-11-01
We have studied Yang-Baxter deformations of supercoset sigma models with ℤ4m grading. The deformations are specified by a skew-symmetric classical r-matrix satisfying the classical Yang-Baxter equations. The deformed action is constructed and the Lax pair is also presented. When m=1, our results reduce to those of the type IIB Green-Schwarz superstring on AdS 5×S 5 background recently given by Kawaguchi, Matsumoto and Yoshida. Supported by National Natural Science Foundation of China (11375141, 11425522, 11547050), Natural Science Foundation of Shaanxi Province (2013JQ1011, 2017ZDJC-32, 2016JM1027), Special Foundation for Basic Scientific Research of Central Colleges (310812152001, 310812172001, 2013G1121082, CHD2012JC019), Scientific Research Program Funded by Shaanxi Provincial Education Department (2013JK0628), Xi’an Shiyou University Science and Technology Foundation (2010QN018) and partly supported by the Basic Research Foundation of Engineering University of CAPF (WJY-201506)
Width of the confining string in Yang-Mills theory.
Gliozzi, F; Pepe, M; Wiese, U-J
2010-06-11
We investigate the transverse fluctuations of the confining string connecting two static quarks in (2+1)D SU(2) Yang-Mills theory using Monte Carlo calculations. The exponentially suppressed signal is extracted from the large noise by a very efficient multilevel algorithm. The resulting width of the string increases logarithmically with the distance between the static quark charges. Corrections at intermediate distances due to universal higher-order terms in the effective string action are calculated analytically. They accurately fit the numerical data.
Infrared propagators of Yang-Mills theory from perturbation theory
DOE Office of Scientific and Technical Information (OSTI.GOV)
Tissier, Matthieu; Wschebor, Nicolas
2010-11-15
We show that the correlation functions of ghosts and gluons for the pure Yang-Mills theory in Landau gauge can be accurately reproduced for all momenta by a one-loop calculation. The key point is to use a massive extension of the Faddeev-Popov action. The agreement with lattice simulation is excellent in d=4. The one-loop calculation also reproduces all the characteristic features of the lattice simulations in d=3 and naturally explains the peculiarities of the propagators in d=2.
SU(2) Yang-Mills solitons in R2 gravity
NASA Astrophysics Data System (ADS)
Perapechka, I.; Shnir, Ya.
2018-05-01
We construct new family of spherically symmetric regular solutions of SU (2) Yang-Mills theory coupled to pure R2 gravity. The particle-like field configurations possess non-integer non-Abelian magnetic charge. A discussion of the main properties of the solutions and their differences from the usual Bartnik-McKinnon solitons in the asymptotically flat case is presented. It is shown that there is continuous family of linearly stable non-trivial solutions in which the gauge field has no nodes.
Yang-Mills correlators across the deconfinement phase transition
NASA Astrophysics Data System (ADS)
Reinosa, U.; Serreau, J.; Tissier, M.; Tresmontant, A.
2017-02-01
We compute the finite temperature ghost and gluon propagators of Yang-Mills theory in the Landau-DeWitt gauge. The background field that enters the definition of the latter is intimately related with the (gauge-invariant) Polyakov loop and serves as an equivalent order parameter for the deconfinement transition. We use an effective gauge-fixed description where the nonperturbative infrared dynamics of the theory is parametrized by a gluon mass which, as argued elsewhere, may originate from the Gribov ambiguity. In this scheme, one can perform consistent perturbative calculations down to infrared momenta, which have been shown to correctly describe the phase diagram of Yang-Mills theories in four dimensions as well as the zero-temperature correlators computed in lattice simulations. In this article, we provide the one-loop expressions of the finite temperature Landau-DeWitt ghost and gluon propagators for a large class of gauge groups and present explicit results for the SU(2) case. These are substantially different from those previously obtained in the Landau gauge, which corresponds to a vanishing background field. The nonanalyticity of the order parameter across the transition is directly imprinted onto the propagators in the various color modes. In the SU(2) case, this leads, for instance, to a cusp in the electric and magnetic gluon susceptibilities as well as similar signatures in the ghost sector. We mention the possibility that such distinctive features of the transition could be measured in lattice simulations in the background field gauge studied here.
Reformulations of the Yang-Mills theory toward quark confinement and mass gap
NASA Astrophysics Data System (ADS)
Kondo, Kei-Ichi; Kato, Seikou; Shibata, Akihiro; Shinohara, Toru
2016-01-01
We propose the reformulations of the SU (N) Yang-Mills theory toward quark confinement and mass gap. In fact, we have given a new framework for reformulating the SU (N) Yang-Mills theory using new field variables. This includes the preceding works given by Cho, Faddeev and Niemi, as a special case called the maximal option in our reformulations. The advantage of our reformulations is that the original non-Abelian gauge field variables can be changed into the new field variables such that one of them called the restricted field gives the dominant contribution to quark confinement in the gauge-independent way. Our reformulations can be combined with the SU (N) extension of the Diakonov-Petrov version of the non-Abelian Stokes theorem for the Wilson loop operator to give a gauge-invariant definition for the magnetic monopole in the SU (N) Yang-Mills theory without the scalar field. In the so-called minimal option, especially, the restricted field is non-Abelian and involves the non-Abelian magnetic monopole with the stability group U (N- 1). This suggests the non-Abelian dual superconductivity picture for quark confinement. This should be compared with the maximal option: the restricted field is Abelian and involves only the Abelian magnetic monopoles with the stability group U(1)N-1, just like the Abelian projection. We give some applications of this reformulation, e.g., the stability for the homogeneous chromomagnetic condensation of the Savvidy type, the large N treatment for deriving the dimensional transmutation and understanding the mass gap, and also the numerical simulations on a lattice which are given by Dr. Shibata in a subsequent talk.
Reformulations of the Yang-Mills theory toward quark confinement and mass gap
DOE Office of Scientific and Technical Information (OSTI.GOV)
Kondo, Kei-Ichi; Shinohara, Toru; Kato, Seikou
2016-01-22
We propose the reformulations of the SU (N) Yang-Mills theory toward quark confinement and mass gap. In fact, we have given a new framework for reformulating the SU (N) Yang-Mills theory using new field variables. This includes the preceding works given by Cho, Faddeev and Niemi, as a special case called the maximal option in our reformulations. The advantage of our reformulations is that the original non-Abelian gauge field variables can be changed into the new field variables such that one of them called the restricted field gives the dominant contribution to quark confinement in the gauge-independent way. Our reformulationsmore » can be combined with the SU (N) extension of the Diakonov-Petrov version of the non-Abelian Stokes theorem for the Wilson loop operator to give a gauge-invariant definition for the magnetic monopole in the SU (N) Yang-Mills theory without the scalar field. In the so-called minimal option, especially, the restricted field is non-Abelian and involves the non-Abelian magnetic monopole with the stability group U (N− 1). This suggests the non-Abelian dual superconductivity picture for quark confinement. This should be compared with the maximal option: the restricted field is Abelian and involves only the Abelian magnetic monopoles with the stability group U(1){sup N−1}, just like the Abelian projection. We give some applications of this reformulation, e.g., the stability for the homogeneous chromomagnetic condensation of the Savvidy type, the large N treatment for deriving the dimensional transmutation and understanding the mass gap, and also the numerical simulations on a lattice which are given by Dr. Shibata in a subsequent talk.« less
Novel Nanoscale Materials for Energy Conversion Applications
2011-03-10
Kuljanishvili, I. Dikin D., S. Rozhok, S. Mayle, V. Chandrasekhar,: Controllable Patterning and CVD Growth of Isolated Carbon Nanotubes with Direct Parallel...catalyst particles”, I. Kuljanishvili, O. Loh, D. Dikin , H. Espinosa, R. Piner, R. S. Ruoff and V. Chandrasekhar, March Meeting of the Am. Phys. Soc... Dikin , S. Rozhok, S. Mayle and V. Chandrasekhar, March Meeting of the Am. Phys. Soc., Pittsburg, Pennsylvania, 2009 (oral presentation). 3
NASA Astrophysics Data System (ADS)
Yamanaka, Masayuki; Maeda, Keiichi; Tanaka, Masaomi; Tominaga, Nozomu; Kawabata, Koji S.; Takaki, Katsutoshi; Kawabata, Miho; Nakaoka, Tatsuya; Ueno, Issei; Akitaya, Hiroshi; Nagayama, Takahiro; Takahashi, Jun; Honda, Satoshi; Omodaka, Toshihiro; Miyanoshita, Ryo; Nagao, Takashi; Watanabe, Makoto; Isogai, Mizuki; Arai, Akira; Itoh, Ryosuke; Ui, Takahiro; Uemura, Makoto; Yoshida, Michitoshi; Hanayama, Hidekazu; Kuroda, Daisuke; Ukita, Nobuharu; Yanagisawa, Kenshi; Izumiura, Hideyuki; Saito, Yoshihiko; Masumoto, Kazunari; Ono, Rikako; Noguchi, Ryo; Matsumoto, Katsura; Nogami, Daisaku; Morokuma, Tomoki; Oasa, Yumiko; Sekiguchi, Kazuhiro
2016-10-01
We present extensively dense observations of the super-Chandrasekhar supernova (SC SN) candidate SN 2012dn from -11 to +140 d after the date of its B-band maximum in the optical and near-infrared (NIR) wavelengths conducted through the OISTER ToO (Optical and Infrared Synergetic Telescopes for Education and Research Target of Opportunity) program. The NIR light curves and color evolutions up to 35 days after the B-band maximum provided an excellent match with those of another SC SN 2009dc, providing further support to the nature of SN 2012dn as an SC SN. We found that SN 2012dn exhibited strong excesses in the NIR wavelengths from 30 d after the B-band maximum. The H- and Ks-band light curves exhibited much later maximum dates at 40 and 70 d after the B-band maximum, respectively, compared with those of normal SNe Ia. The H- and Ks-band light curves subtracted by those of SN 2009dc displayed plateaued evolutions, indicating an NIR echo from the surrounding dust. The distance to the inner boundary of the dust shell is limited to 4.8-6.4 × 10-2 pc. No emission lines were found in its early phase spectra, suggesting that the ejecta-circumstellar material interaction could not occur. On the other hand, we found no signature that strongly supports the scenario of dust formation. The mass-loss rate of the pre-explosion system is estimated to be 10-6-10-5 M⊙ yr-1, assuming that the wind velocity of the system is 10-100 km s-1, which suggests that the progenitor of SN 2012dn could be a recurrent nova system. We conclude that the progenitor of this SC SN could be explained by the single-degenerate scenario.
Owen, Sioned; Zhao, Huishan; Dart, Alwyn; Wang, Yamei; Ruge, Fiona; Gao, Yong; Wei, Cong; Wu, Yiling; Jiang, Wen G
2016-11-01
Heat shock protein 27 (HSP27) is a member of the heat shock protein family which has been linked to tumour progression and, most interestingly, to chemotherapy resistance in cancer patients. The present study examined the potential interplay between HSP27 and YangZheng XiaoJi, a traditional Chinese medicine used in cancer treatment. A range of cell lines from different tumour types including pancreatic, lung, gastric, colorectal, breast, prostate and ovarian cancer (both wild-type and resistant) were used. Levels and activation of HSP27 and its potential associated signalling pathways were evaluated by protein array and western blotting. Knockdown of HSP27 in cancer cells was achieved using siRNA. Localisation and co-localisation of HSP27 and other proteins were carried out by immunofluorescence. Cell growth and migration were evaluated in their response to a range of chemotherapeutic agents. The present study first identified, by way of protein array, that YangZheng XiaoJi was able to inhibit the phosphorylation of HSP27 protein in cancer cells. We further demonstrated that HSP27, which is co-localised with caspase-9, can be blocked from localising in focal adhesions and co-localising with caspase-9 by YangZheng XiaoJi. The study also demonstrated that YangZheng XiaoJi was able to sensitise cancer cells including those cells that were resistant to chemotherapy, to chemotherapeutic agents. Finally, knocking down HSP27 markedly reduced the migration of cancer cells and increased the sensitivity of cancer cells to the inhibitory effect on cellular migration by YangZheng XiaoJi. YangZheng XiaoJi can act as an agent in first sensitising cancer cells to chemotherapy and secondly to overcome, to some degree, chemoresistance when used in an appropriate fashion in patients who have active HSP27.
Yang, Shunfang; Shi, Meiping; Cao, Jie; Su, Jianzhong; Zhao, Lanxiang; Lei, Bei; Chang, Cheng; Lu, Jianying; Ye, Jianding; Xie, Wenhui
2011-02-01
The recurrence and metastasis of lung cancer is a tough problem worldwide. The aim of this study is to establish a novel Chinese lung adenocarcinoma cell line and its real bone-seeking clone sub-line for exploring the molecular mechanism of lung cancer metastasis. The cells came from the pleural effusion of a sixty-five years old female patient with lung adenocarcinoma and supraclavicular lymph node metastases. The gene expression was detected by real-time quantitative PCR. Intracardiac injection of the cells into nude mice was performed and in vivo imaging was obtained by bone scintigraphy and conventional radiography. Bone metastases were determined on bone scintigraphy and then the lesions were resected under deep anesthesia for bone metastasis cancer cell culture. The process was repeated for four cycles to obtain a real bone-seeking clone. The tumorigenesis rate started at 4th passage in immunodeficient mice via subcutaneously and as well as later passages. Approximately 1×10⁶ cancer cells were injected into left cardiac ventricle of immunodeficient mice resulted bone metastasis sites were successfully revealed by bone scintigraphy and pathological diagnosis, the mandible (100%), scapula (33%), humerus (50%), vertebral column (50%), femur (66.7%) and accompanied invasion with other organs, the adrenal gland (17%), pulmonary (33%), liver (50%), submaxillary gland (33%) in the mice after inoculation two-three weeks. The chromosome karyotype analysis of the cells was subdiploid. Quantitative real-time PCR was used to examined and compared with SPC-A-1 lung adenocarcinoma, ESM1, VEGF-C, IL-6, IL-8, AR, SVIL, FN1 genes were overexpress. The novel cell was named CPA-Yang3. The femur metastasis cell was repeated in vivo-in vitro-in vivo with three cycles and harvested a real bone metastasis clone. It was named CPA-Yang3BM. Tne characteristics of novel strain CPAYang3 is a highly metastasis cell line of Chinese lung adenocarcinoma and CPA-Yang3BM is a real bone
Easier Said than Done: Rejoinder on Sijtsma and on Green and Yang
ERIC Educational Resources Information Center
Davenport, Ernest C.; Davison, Mark L.; Liou, Pey-Yan; Love, Quintin U.
2016-01-01
The main points of Sijtsma and Green and Yang in Educational Measurement: Issues and Practice (34, 4) are that reliability, internal consistency, and unidimensionality are distinct and that Cronbach's alpha may be problematic. Neither of these assertions are at odds with Davenport, Davison, Liou, and Love in the same issue. However, many authors…
An ancient Chinese wisdom for metabolic engineering: Yin-Yang
DOE Office of Scientific and Technical Information (OSTI.GOV)
Wu, Stephen G.; He, Lian; Wang, Qingzhao
In ancient Chinese philosophy, Yin-Yang describes two contrary forces that are interconnected and interdependent. This concept also holds true in microbial cell factories, where Yin represents energy metabolism in the form of ATP, and Yang represents carbon metabolism. Current biotechnology can effectively edit the microbial genome or introduce novel enzymes to redirect carbon fluxes. On the other hand, microbial metabolism loses significant free energy as heat when converting sugar into ATP; while maintenance energy expenditures further aggravate ATP shortage. The limitation of cell “powerhouse” prevents hosts from achieving high carbon yields and rates. Via an Escherichia coli flux balance analysismore » model, we further demonstrate the penalty of ATP cost on biofuel synthesis. To ensure cell powerhouse being sufficient in microbial cell factories, we propose five principles: 1. Take advantage of native pathways for product synthesis. 2. Pursue biosynthesis relying only on pathways or genetic parts without significant ATP burden. 3. Combine microbial production with chemical conversions (semi-biosynthesis) to reduce biosynthesis steps. 4. Create “minimal cells” or use non-model microbial hosts with higher energy fitness. 5. Develop a photosynthesis chassis that can utilize light energy and cheap carbon feedstocks. Meanwhile, metabolic flux analysis can be used to quantify both carbon and energy metabolisms. The fluxomics results are essential to evaluate the industrial potential of laboratory strains, avoiding false starts and dead ends during metabolic engineering« less
An ancient Chinese wisdom for metabolic engineering: Yin-Yang
Wu, Stephen G.; He, Lian; Wang, Qingzhao; ...
2015-03-20
In ancient Chinese philosophy, Yin-Yang describes two contrary forces that are interconnected and interdependent. This concept also holds true in microbial cell factories, where Yin represents energy metabolism in the form of ATP, and Yang represents carbon metabolism. Current biotechnology can effectively edit the microbial genome or introduce novel enzymes to redirect carbon fluxes. On the other hand, microbial metabolism loses significant free energy as heat when converting sugar into ATP; while maintenance energy expenditures further aggravate ATP shortage. The limitation of cell “powerhouse” prevents hosts from achieving high carbon yields and rates. Via an Escherichia coli flux balance analysismore » model, we further demonstrate the penalty of ATP cost on biofuel synthesis. To ensure cell powerhouse being sufficient in microbial cell factories, we propose five principles: 1. Take advantage of native pathways for product synthesis. 2. Pursue biosynthesis relying only on pathways or genetic parts without significant ATP burden. 3. Combine microbial production with chemical conversions (semi-biosynthesis) to reduce biosynthesis steps. 4. Create “minimal cells” or use non-model microbial hosts with higher energy fitness. 5. Develop a photosynthesis chassis that can utilize light energy and cheap carbon feedstocks. Meanwhile, metabolic flux analysis can be used to quantify both carbon and energy metabolisms. The fluxomics results are essential to evaluate the industrial potential of laboratory strains, avoiding false starts and dead ends during metabolic engineering« less
The Yin and Yang of Calcium Effects on Synaptic Vesicle Endocytosis
Wu, Xin-Sheng
2014-01-01
A large number of studies suggest that calcium triggers and accelerates vesicle endocytosis at many synapses and non-neuronal secretory cells. However, many studies show that prolonging the duration of the stimulation train, which induces more calcium influx, slows down endocytosis; and several studies suggest that instead of triggering endocytosis, calcium actually inhibits endocytosis. Here we addressed this apparent conflict at a large nerve terminal, the calyx of Held in rat brainstem, in which recent studies suggest that transient calcium increase up to tens of micromolar concentration at the micro/nano domain triggers endocytosis. By dialyzing 0–1 μm calcium into the calyx via a whole-cell pipette, we found that slow endocytosis was inhibited by calcium dialysis in a concentration-dependent manner. Thus, prolonged, small, and global calcium increase inhibits endocytosis, whereas transient and large calcium increase at the micro/nano domain triggers endocytosis and facilitates endocytosis. This yin and yang effect of calcium may reconcile apparent conflicts regarding whether calcium accelerates or inhibits endocytosis. Whether endocytosis is fast or slow depends on the net outcome between the yin and yang effect of calcium. PMID:24523554
Lee-Yang Polynomials and Ground States of Spin Systems
NASA Astrophysics Data System (ADS)
Slawny, Joseph
2014-08-01
We obtain two kinds of results on the region in the space of the interactions of lattice systems where the Lee-Yang property holds (LY domain). First we show that the LY domain is related to interactions with exactly two ground states. Then we give a description of the full LY domain of an extended "plaquette model" analyzed by Lebowitz and Ruelle (Commun Math Phys 304:711-722,
NASA Astrophysics Data System (ADS)
Delduc, F.; Hoare, B.; Kameyama, T.; Magro, M.
2017-10-01
A multi-parameter integrable deformation of the principal chiral model is presented. The Yang-Baxter and bi-Yang-Baxter σ-models, the principal chiral model plus a Wess-Zumino term and the TsT transformation of the principal chiral model are all recovered when the appropriate deformation parameters vanish. When the Lie group is SU(2), we show that this four-parameter integrable deformation of the SU(2) principal chiral model corresponds to the Lukyanov model.
Two-dimensional N = 2 Super-Yang-Mills Theory
NASA Astrophysics Data System (ADS)
August, Daniel; Wellegehausen, Björn; Wipf, Andreas
2018-03-01
Supersymmetry is one of the possible scenarios for physics beyond the standard model. The building blocks of this scenario are supersymmetric gauge theories. In our work we study the N = 1 Super-Yang-Mills (SYM) theory with gauge group SU(2) dimensionally reduced to two-dimensional N = 2 SYM theory. In our lattice formulation we break supersymmetry and chiral symmetry explicitly while preserving R symmetry. By fine tuning the bar-mass of the fermions in the Lagrangian we construct a supersymmetric continuum theory. To this aim we carefully investigate mass spectra and Ward identities, which both show a clear signal of supersymmetry restoration in the continuum limit.
T -folds from Yang-Baxter deformations
NASA Astrophysics Data System (ADS)
Fernández-Melgarejo, José J.; Sakamoto, Jun-ichi; Sakatani, Yuho; Yoshida, Kentaroh
2017-12-01
Yang-Baxter (YB) deformations of type IIB string theory have been well studied from the viewpoint of classical integrability. Most of the works, however, are focused upon the local structure of the deformed geometries and the global structure still remains unclear. In this work, we reveal a non-geometric aspect of YB-deformed backgrounds as T -fold by explicitly showing the associated O( D, D; ℤ) T -duality monodromy. In particular, the appearance of an extra vector field in the generalized supergravity equations (GSE) leads to the non-geometric Q-flux. In addition, we study a particular solution of GSE that is obtained by a non-Abelian T-duality but cannot be expressed as a homogeneous YB deformation, and show that it can also be regarded as a T -fold. This result indicates that solutions of GSE should be non-geometric quite in general beyond the YB deformation.
NASA Astrophysics Data System (ADS)
Kondo, Kei-Ichi; Kato, Seikou; Shibata, Akihiro; Shinohara, Toru
2015-05-01
The purpose of this paper is to review the recent progress in understanding quark confinement. The emphasis of this review is placed on how to obtain a manifestly gauge-independent picture for quark confinement supporting the dual superconductivity in the Yang-Mills theory, which should be compared with the Abelian projection proposed by 't Hooft. The basic tools are novel reformulations of the Yang-Mills theory based on change of variables extending the decomposition of the SU(N) Yang-Mills field due to Cho, Duan-Ge and Faddeev-Niemi, together with the combined use of extended versions of the Diakonov-Petrov version of the non-Abelian Stokes theorem for the SU(N) Wilson loop operator. Moreover, we give the lattice gauge theoretical versions of the reformulation of the Yang-Mills theory which enables us to perform the numerical simulations on the lattice. In fact, we present some numerical evidences for supporting the dual superconductivity for quark confinement. The numerical simulations include the derivation of the linear potential for static interquark potential, i.e., non-vanishing string tension, in which the "Abelian" dominance and magnetic monopole dominance are established, confirmation of the dual Meissner effect by measuring the chromoelectric flux tube between quark-antiquark pair, the induced magnetic-monopole current, and the type of dual superconductivity, etc. In addition, we give a direct connection between the topological configuration of the Yang-Mills field such as instantons/merons and the magnetic monopole. We show especially that magnetic monopoles in the Yang-Mills theory can be constructed in a manifestly gauge-invariant way starting from the gauge-invariant Wilson loop operator and thereby the contribution from the magnetic monopoles can be extracted from the Wilson loop in a gauge-invariant way through the non-Abelian Stokes theorem for the Wilson loop operator, which is a prerequisite for exhibiting magnetic monopole dominance for quark
Yang-Mills theory and the ABC conjecture
NASA Astrophysics Data System (ADS)
He, Yang-Hui; Hu, Zhi; Probst, Malte; Read, James
2018-05-01
We establish a precise correspondence between the ABC Conjecture and 𝒩 = 4 super-Yang-Mills theory. This is achieved by combining three ingredients: (i) Elkies’ method of mapping ABC-triples to elliptic curves in his demonstration that ABC implies Mordell/Faltings; (ii) an explicit pair of elliptic curve and associated Belyi map given by Khadjavi-Scharaschkin; and (iii) the fact that the bipartite brane-tiling/dimer model for a gauge theory with toric moduli space is a particular dessin d’enfant in the sense of Grothendieck. We explore this correspondence for the highest quality ABC-triples as well as large samples of random triples. The conjecture itself is mapped to a statement about the fundamental domain of the toroidal compactification of the string realization of 𝒩 = 4 SYM.
Shen, Cimin; Xu, Jinsen; Zheng, Shuxia; Lin, Lijiao; Yang, Xiaomei; Liu, Chunlan
2016-02-01
To observe the effect of electroacupuncture(EA) at Zhongwan(CV 12) on the energy metabolism along the conception vessel(CV) in volunteers with yang-deficiency constitution,and to explore the relationship of electroacupuncture regulation and body constitution. Eighteen volunteers with mild constitution and 18 volunteers with yang-deficiency constitution were collected out of 200 students of Fujian University of TCM by body constitution questionnaire. Skin microcirculatory blood perfusion units (MBPU) at Danzhong (CV 17), Xiawan(CV 10) and Qihai(CV 6) of CV were measured by a laser Doppler flowmetry in the normal condition and after EA stimulation at Zhongwan(CV 12) for 20 min. (1)Before treatment, (1)MBPU values at Danzhong(CV 17), Xiawan(CV 10) and Qihai(CV 6) in the yang-deficiency constitution group were lower than those in the mild constitution group,but there was no statistical significance (both P>0. 05) except Danzhong(CV 17) (P<0. 01). (Z)As for the three acupoints in the mild constitution group, MBPU level of Danzhong(CV 17) was higher than that of Xiawan(CV 10) without statistical significance(P->0. 05),and MBPU values of Danzhong(CV 17) and Xiawan(CV 10) were higher than that of Qihai(CV 6) (both P<0. 01). (3About the three acupoints in the yang-deficiency constitution group, MBPU result of Danzhong(CV 17) was lower than the value of Xiawan(CV 10), but higher compared with Qihai(CV 6)(P<0. 05, P<0. 01). MBPU of Xiawan(CV 10) was higher than Qihai (CV 6) as well(P<0. 01). (2) MBPU values of Danzhong(CV 17), Xiawan(CV 10) and Qihai(CV 6) were increased apparently compared with those before treatment after EA stimulation at Zhongwan(CV 12) for 20 min in the two groups(all P<0. 01). (3) The rise rates of MBPU level about Danzhong(CV 17) and Qihai(CV 6) in the yang-deficiency constitution group were higher than those in the mild constitution group without statistical significance after EA at Zhongwan(CV 12) for 20 min(both P>0. 05). The energy metabolism in CV
Architecutres, Models, Algorithms, and Software Tools for Configurable Computing
2000-03-06
and J.G. Nash. The gated interconnection network for dynamic programming. Plenum, 1988 . [18] Ju wook Jang, Heonchul Park, and Viktor K. Prasanna. A ...Sep. 1997. [2] C. Ebeling, D. C. Cronquist , P. Franklin and C. Fisher, "RaPiD - A configurable computing architecture for compute-intensive...ABSTRACT (Maximum 200 words) The Models, Algorithms, and Architectures for Reconfigurable Computing (MAARC) project developed a sound framework for
Einstein-Yang-Mills scattering amplitudes from scattering equations
NASA Astrophysics Data System (ADS)
Cachazo, Freddy; He, Song; Yuan, Ellis Ye
2015-01-01
We present the building blocks that can be combined to produce tree-level S-matrix elements of a variety of theories with various spins mixed in arbitrary dimensions. The new formulas for the scattering of n massless particles are given by integrals over the positions of n points on a sphere restricted to satisfy the scattering equations. As applications, we obtain all single-trace amplitudes in Einstein-Yang-Mills (EYM) theory, and generalizations to include scalars. Also in EYM but extended by a B-field and a dilaton, we present all double-trace gluon amplitudes. The building blocks are made of Pfaffians and Parke-Taylor-like factors of subsets of particle labels.
Huang, Sheng-Miauh; Chien, Li-Yin; Tai, Cheng-Jeng; Chen, Ping-Ho; Lien, Pei-Ju; Tai, Chen-Jei
2015-04-01
Based on traditional Chinese medicine (TCM) theory, yang deficiency pattern defined as an insufficiency of meridian energy (qi) is related to worsening disease symptoms. However, there is a lack of studies portraying the relationship among complementary and alternative medicine (CAM) use, symptoms, and meridian energy. Therefore, the primary purpose of this study was to describe the changes of CAM use, symptoms, and yang deficiency pattern among patients with breast cancer receiving chemotherapy. Additionally, the study explored factors predicting yang deficiency pattern. A longitudinal study was performed with 153 women with breast cancer at four teaching hospitals in northern Taiwan from June 1, 2009 to July 31, 2013. Researchers collected data before treatment and the 1st and 3rd months after chemotherapy. Yang deficiency pattern was examined using the Meridian Energy Analysis Device Me-Pro. Symptom severity and interference were assessed using the MD Anderson Symptom Inventory-Taiwan version. CAM use was evaluated using the US National Center for Complementary and Alternative Medicine (NCCAM) classification. Meridian energy remained essentially the same over the 3-month period as the difference was not statistically significant. As time went by, patients developed worsening symptom severity and interference. More than 66% of the patients used CAM during chemotherapy. Older women had lower overall meridian energy. The more severe the symptoms were, the lower the overall meridian energy was. The patients who used tai chi or qi gong had higher overall meridian energy and those who used prayer or spirituality had lower overall meridian energy. Symptom severity and interference among patients deteriorated during chemotherapy. Health providers should observe symptom changes and improve yang deficiency pattern. Whether or not use of CAM practices such as tai chi or qi gong improves the overall health of breast cancer patients on chemotherapy is worth further study
Fuzzy CMAC With incremental Bayesian Ying-Yang learning and dynamic rule construction.
Nguyen, M N
2010-04-01
Inspired by the philosophy of ancient Chinese Taoism, Xu's Bayesian ying-yang (BYY) learning technique performs clustering by harmonizing the training data (yang) with the solution (ying). In our previous work, the BYY learning technique was applied to a fuzzy cerebellar model articulation controller (FCMAC) to find the optimal fuzzy sets; however, this is not suitable for time series data analysis. To address this problem, we propose an incremental BYY learning technique in this paper, with the idea of sliding window and rule structure dynamic algorithms. Three contributions are made as a result of this research. First, an online expectation-maximization algorithm incorporated with the sliding window is proposed for the fuzzification phase. Second, the memory requirement is greatly reduced since the entire data set no longer needs to be obtained during the prediction process. Third, the rule structure dynamic algorithm with dynamically initializing, recruiting, and pruning rules relieves the "curse of dimensionality" problem that is inherent in the FCMAC. Because of these features, the experimental results of the benchmark data sets of currency exchange rates and Mackey-Glass show that the proposed model is more suitable for real-time streaming data analysis.
{{SO(d,1)}}-Invariant Yang-Baxter Operators and the dS/CFT Correspondence
NASA Astrophysics Data System (ADS)
Hollands, Stefan; Lechner, Gandalf
2018-01-01
We propose a model for the dS/CFT correspondence. The model is constructed in terms of a "Yang-Baxter operator" R for unitary representations of the de Sitter group {SO(d,1)}. This R-operator is shown to satisfy the Yang-Baxter equation, unitarity, as well as certain analyticity relations, including in particular a crossing symmetry. With the aid of this operator we construct: (a) a chiral (light-ray) conformal quantum field theory whose internal degrees of freedom transform under the given unitary representation of {SO(d,1)}. By analogy with the O( N) non-linear sigma model, this chiral CFT can be viewed as propagating in a de Sitter spacetime. (b) A (non-unitary) Euclidean conformal quantum field theory on R}^{d-1, where SO( d, 1) now acts by conformal transformations in (Euclidean) spacetime. These two theories can be viewed as dual to each other if we interpret R}^{d-1 as conformal infinity of de Sitter spacetime. Our constructions use semi-local generator fields defined in terms of R and abstract methods from operator algebras.
Non-Perturbative Yang-Mills from Supersymmetry and Strings, Or, in the Jungles of Strong Coupling
NASA Astrophysics Data System (ADS)
Shifman, M.
2005-12-01
I summarize some recent developments in the issue of planar equivalence between supersymmetric Yang-Mills theory and its orbifold/orientifold daughters. This talk is based on works carried out in collaboration with Adi Armoni, Sasha Gorsky and Gabriele Veneziano.
Non-Perturbative Yang--Mills from Supersymmetry and Strings, or, in the Jungles of Strong Coupling
NASA Astrophysics Data System (ADS)
Shifman, M.
2005-12-01
I summarize some recent developments in the issue of planar equivalence between supersymmetric Yang--Mills theory and its orbifold/orientifold daughters. This talk is based on works carried out in collaboration with Adi Armoni, Sasha Gorsky and Gabriele Veneziano.
Non-Perturbative Yang-Mills from Supersymmetry and Strings, or, in the Jungles of Strong Coupling
NASA Astrophysics Data System (ADS)
Shifman, M.
2006-06-01
I summarize some recent developments in the issue of planar equivalence between supersymmetric Yang-Mills theory and its orbifold/orientifold daughters. This talk is based on works carried out in collaboration with Adi Armoni, Sasha Gorsky and Gabriele Veneziano.
NASA Astrophysics Data System (ADS)
Links, Jon
2017-03-01
Solutions of the classical Yang-Baxter equation provide a systematic method to construct integrable quantum systems in an algebraic manner. A Lie algebra can be associated with any solution of the classical Yang-Baxter equation, from which commuting transfer matrices may be constructed. This procedure is reviewed, specifically for solutions without skew-symmetry. A particular solution with an exotic symmetry is identified, which is not obtained as a limiting expansion of the usual Yang-Baxter equation. This solution facilitates the construction of commuting transfer matrices which will be used to establish the integrability of a multi-species boson tunnelling model. The model generalises the well-known two-site Bose-Hubbard model, to which it reduces in the one-species limit. Due to the lack of an apparent reference state, application of the algebraic Bethe Ansatz to solve the model is prohibitive. Instead, the Bethe Ansatz solution is obtained by the use of operator identities and tensor product decompositions.
Some exact solutions of (2+1)-dimensional Yang-Mills equations with the Chern-Simons term
DOE Office of Scientific and Technical Information (OSTI.GOV)
Oh, C. H.; Sia, L. C.; Teh, R.
1989-07-15
Two /ital Ansa/$/ital uml/---/ital tze/ for the gauge field potential are given so that the(2+1)-dimensional Yang-Mills equations with the Chern-Simons termcan be solved in terms of the modified Bessel functions and the ellipticfunction respectively.
1999-07-19
KENNEDY SPACE CENTER, FLA. -- Mrs. Lalitha Chandrasekhar, wife of the late Indian-American Nobel Laureate Subrahmanyan Chandrasekhar, poses with a model of the Chandra X-ray Observatory in the TRW Media Hospitality Tent at the NASA Press Site at KSC. The name "Chandra," a shortened version of Chandrasekhar's name which he preferred among friends and colleagues, was chosen in a contest to rename the telescope. "Chandra" also means "Moon" or "luminous" in Sanskrit. The observatory is scheduled to be launched aboard Columbia on Space Shuttle mission STS-93
Yan, Yuxuan; Pan, Chang; Wu, Jie; Yang, Lijie
2017-01-12
To observe the clinical efficacy of acupuncture and moxibustion periodic therapy on folli-cular maldevelopment differentiated as spleen and kidney yang deficiency. Sixty patients of follicular maldevelopment differentiated as spleen and kidney yang deficiency were randomized as an observation group and a control group, 30 cases in each one. The conventional acupuncture-moxibustion therapy was used in the control group and the acupuncture-moxibustion periodic therapy was applied to the observation group. In the control group, the acupoints were selected in terms of spleen and kidney yang deficiency, such as Guanyuan (CV 4), Qihai (CV 6), Zusanli (ST 36), Sanyinjiao (SP 6), Taixi (KI 3), Xuehai (SP 10) and Zigong (EX-CA 1). In the observation group, the acupoints were selected in terms of the physiological characteristics of follicular phase, ovulatory phase, luteal phase and menstrual phase. The main acupoints were Zusanli (ST 36), Sanyinjiao (SP 6), Taixi (KI 3) and Xuehai (SP 10). The acupoints for benefiting kidney yin were added in the follicular phase, such as Guanyuan (CV 4) and Dahe (KI 12), etc. The acupoints for regulating qi and activating blood circulation were added in the ovulatory phase, such as Hegu (LI 4) and Taichong (LR 3), etc. The moxibustion was added for tonifying kidney yang in the luteal phase, such as Qihai (CV 6) and Guanyuan (CV 4). The treatment was discontinued during the menstrual phase in the two groups. In the rest phases, acupuncture and moxibustion were given once every two days, 30 min each time. The overall efficacy, basal body temperature (BBT), follicular development, the average endometrial thickness and morphology as well as TCM syndrome score of spleen and kidney yang deficiency were observed in the patients after 3-month menstrual periods. The adverse reactions were recorded in the two groups. In the observation group, one case gave up the treatment due to the personal reason and another one stopped the treatment due to
Constructing the tree-level Yang-Mills S-matrix using complex factorization
NASA Astrophysics Data System (ADS)
Schuster, Philip C.; Toro, Natalia
2009-06-01
A remarkable connection between BCFW recursion relations and constraints on the S-matrix was made by Benincasa and Cachazo in 0705.4305, who noted that mutual consistency of different BCFW constructions of four-particle amplitudes generates non-trivial (but familiar) constraints on three-particle coupling constants — these include gauge invariance, the equivalence principle, and the lack of non-trivial couplings for spins > 2. These constraints can also be derived with weaker assumptions, by demanding the existence of four-point amplitudes that factorize properly in all unitarity limits with complex momenta. From this starting point, we show that the BCFW prescription can be interpreted as an algorithm for fully constructing a tree-level S-matrix, and that complex factorization of general BCFW amplitudes follows from the factorization of four-particle amplitudes. The allowed set of BCFW deformations is identified, formulated entirely as a statement on the three-particle sector, and using only complex factorization as a guide. Consequently, our analysis based on the physical consistency of the S-matrix is entirely independent of field theory. We analyze the case of pure Yang-Mills, and outline a proof for gravity. For Yang-Mills, we also show that the well-known scaling behavior of BCFW-deformed amplitudes at large z is a simple consequence of factorization. For gravity, factorization in certain channels requires asymptotic behavior ~ 1/z2.
Wess-Zumino and super Yang-Mills theories in D=4 integral superspace
NASA Astrophysics Data System (ADS)
Castellani, L.; Catenacci, R.; Grassi, P. A.
2018-05-01
We reconstruct the action of N = 1 , D = 4 Wess-Zumino and N = 1 , 2 , D = 4 super-Yang-Mills theories, using integral top forms on the supermanifold M^{(.4|4)} . Choosing different Picture Changing Operators, we show the equivalence of their rheonomic and superspace actions. The corresponding supergeometry and integration theory are discussed in detail. This formalism is an efficient tool for building supersymmetric models in a geometrical framework.
ERIC Educational Resources Information Center
Clarkson, J. D.
2000-01-01
Notes that Yang's book provides a combination of Eastern and Western philosophy in defining values, aims, and methods of education, research, and teacher preparation programs. Maintains that the book presents important insights into current educational issues. Asserts that problems such as printing errors and significant flaws in arguments add to…
An Overview of MSHN: The Management System for Heterogeneous Networks
1999-04-01
An Overview of MSHN: The Management System for Heterogeneous Networks Debra A. Hensgen†, Taylor Kidd†, David St. John§, Matthew C . Schnaidt†, Howard...ABSTRACT UU 18. NUMBER OF PAGES 15 19a. NAME OF RESPONSIBLE PERSON a. REPORT unclassified b. ABSTRACT unclassified c . THIS PAGE...Alhusaini, V. K. Prasanna, and C . S. Raghavendra, “A unified resource scheduling framework for heterogeneous computing environments,” Proc. 8th IEEE
Asymptotically flat, stable black hole solutions in Einstein-Yang-Mills-Chern-Simons theory.
Brihaye, Yves; Radu, Eugen; Tchrakian, D H
2011-02-18
We construct finite mass, asymptotically flat black hole solutions in d=5 Einstein-Yang-Mills-Chern-Simons theory. Our results indicate the existence of a second order phase transition between Reissner-Nordström solutions and the non-Abelian black holes which generically are thermodynamically preferred. Some of the non-Abelian configurations are also stable under linear, spherically symmetric perturbations.
Sun, Dong-Yue; Wang, Xin-Ya; Wang, Xiao-Ting; Yan, Li; Liu, Xiao-Feng; Pang, Bo; Gao, Hui
2018-06-01
To compare the effect of integration processing technology of origin (IPTO) and traditional cutting processing technology (TCPT) of Moslae Herba for lung-Yang deficiency rats caused by complex factors, analyze the mechanism, and provide the modern pharmacology basis for the implementation of IPTO of Moslae Herba. The rat models of lung-Yang deficiency were established by smoking + swimming in ice water + drinking ice water. The model rats were randomly divided into different groups, and were treated with intragastric administration for 30 d. Then the general signs, anal temperature and autonomic activity of the rats were observed. The pathological morphology of lung tissues was observed, and the positive expression of tumor necrosis factor (TNF-α) was observed by immunohistochemical method, and the hematological indexes were determined. Enzyme linked immunosorbent assay (ELISA) method was used to detect serum nitric oxide (NO), immunoglobulin G (IGG), malondialdehyde (MDA), thromboxane B2 (TXB2) and interleukin-8 (IL-8) level, and the organ coefficients of heart, liver, spleen, lung, kidney and other organs were calculated. According to the results, Moslae Herba volatile oil and decoction could improve the general signs and autonomic activities of lung-Yang deficiency rats, improve the body weight, rectal temperature, and the content of IGG in serum of lung-Yang deficiency rats, reduce organ coefficients of heart, liver, spleen, lung and kidney, serum NO, MDA, TXB2, IL-8 contents, white blood cell and TNF-α mean optical density in the lung tissues of rats. witg statistically significant difference ( P <0.01 or P <0.05). The effects of IPTO volatile oil and water decoction were slightly higher. Therefore, Moslae Herba has therapeutic effect on lung-Yang deficiency rats, and ICPT has better effect, whose mechanism may be related to the intervention of TNF-α expression, improving the level of IGG, and inhibiting NO, MDA, IL-8, and TXB2 levels. Copyright© by the
Explaining the progenitors of peculiar type Ia supernovae
NASA Astrophysics Data System (ADS)
Das, Upasana; Mukhopadhyay, Banibrata
2015-01-01
Type Ia supernovae (SneIa) are believed to be triggered in white dwarfs having mass close to the Chandrasekhar limit of 1.44 M⊙. However, observations of several peculiar, highly under- and over-luminous SNeIa argue for exploding masses widely different from this limit. The over-luminous SNeIa, e.g. SN 2003fg, SN 2006gz, SN 2007if, SN 2009dc, seem to invoke super-Chandrasekhar white dwarf progenitors, having mass 2.1-2.8 M⊙. While, the under-luminous SNeIa, e.g. SN 1991bg, SN 1997cn, SN 1998de, SN 1999by, seem to favor sub-Chandrasekhar explosion scenarios. In order to explain the existence of super-Chandrasekhar white dwarfs, we have exploited the enormous potential of magnetic fields, which can affect the structure and properties of the underlying white dwarf in a variety of ways. We have progressed from a simplistic to more rigorous and self-consistent models in the following sequence - spherically symmetric Newtonian model with a constant central magnetic field; spherically symmetric general relativistic model with varying magnetic field and finally, a model including self-consistent departure from spherical symmetry obtained from general relativistic magnetohydrodynamic (GRMHD) simulations. Here we particularly present the results of the GRMHD simulations, whereby we have constructed equilibrium models of strongly magnetized, static, white dwarfs. Interestingly, we find that significantly super-Chandrasekhar white dwarfs are obtained for many possible field configurations, namely, poloidal, toroidal and mixed. Further, due to the inclusion of deformation in the white dwarf structure caused by a strong magnetic field, super-Chandrasekhar white dwarfs are obtained for relatively lower magnetic field strengths compared to that in the simplistic model. Finally, driven by the aim to establish a unification theory of under- and over-luminous SNeIa, we have shown that a modification of Einstein's theory of gravity leads to both significantly sub- and super-Chandrasekhar
From SL(5, ℝ) Yang-Mills theory to induced gravity
NASA Astrophysics Data System (ADS)
Assimos, T. S.; Pereira, A. D.; Santos, T. R. S.; Sobreiro, R. F.; Tomaz, A. A.; Otoya, V. J. Vasquez
From pure Yang-Mills action for the SL(5, ℝ) group in four Euclidean dimensions we obtain a gravity theory in the first order formalism. Besides the Einstein-Hilbert term, the effective gravity has a cosmological constant term, a curvature squared term, a torsion squared term and a matter sector. To obtain such geometrodynamical theory, asymptotic freedom and the Gribov parameter (soft BRST symmetry breaking) are crucial. Particularly, Newton and cosmological constant are related to these parameters and they also run as functions of the energy scale. One-loop computations are performed and the results are interpreted.
Is the ground state of Yang-Mills theory Coulombic?
NASA Astrophysics Data System (ADS)
Heinzl, T.; Ilderton, A.; Langfeld, K.; Lavelle, M.; Lutz, W.; McMullan, D.
2008-08-01
We study trial states modelling the heavy quark-antiquark ground state in SU(2) Yang-Mills theory. A state describing the flux tube between quarks as a thin string of glue is found to be a poor description of the continuum ground state; the infinitesimal thickness of the string leads to UV artifacts which suppress the overlap with the ground state. Contrastingly, a state which surrounds the quarks with non-Abelian Coulomb fields is found to have a good overlap with the ground state for all charge separations. In fact, the overlap increases as the lattice regulator is removed. This opens up the possibility that the Coulomb state is the true ground state in the continuum limit.
NASA Astrophysics Data System (ADS)
Ashall, C.; Mazzali, P. A.; Stritzinger, M. D.; Hoeflich, P.; Burns, C. R.; Gall, C.; Hsiao, E. Y.; Phillips, M. M.; Morrell, N.; Foley, Ryan J.
2018-06-01
Radiative transfer models of two transitional type Ia supernovae (SNe Ia) have been produced using the abundance stratification technique. These two objects - designated SN 2007on and SN 2011iv - both exploded in the same galaxy, NGC 1404, which allows for a direct comparison. SN 2007on synthesized 0.25 M_{⊙} of 56Ni and was less luminous than SN 2011iv, which produced 0.31 M_{⊙} of 56Ni. SN 2007on had a lower central density (ρc) and higher explosion energy (Ekin ˜1.3 ± 0.3 × 1051erg) than SN 2011iv, and it produced less nuclear statistical equilibrium (NSE) elements (0.06 M_{⊙}). Whereas, SN 2011iv had a larger ρc, which increased the electron capture rate in the lowest velocity regions, and produced 0.35 M_{⊙} of stable NSE elements. SN 2011iv had an explosion energy of ˜Ekin ˜0.9 ± 0.2 × 1051erg. Both objects had an ejecta mass consistent with the Chandrasekhar mass (Ch-mass), and their observational properties are well described by predictions from delayed-detonation explosion models. Within this framework, comparison to the sub-luminous SN 1986G indicates SN 2011iv and SN 1986G have different transition densities (ρtr) but similar ρc. Whereas SN 1986G and SN 2007on had a similar ρtr but different ρc. Finally, we examine the colour-stretch parameter sBV versus Lmax relation and determine that the bulk of SNe Ia (including the sub-luminous ones) are consistent with Ch-mass delayed-detonation explosions, where the main parameter driving the diversity is ρtr. We also find ρc to be driving the second-order scatter observed at the faint end of the luminosity-width relationship.
Yang-Baxter and other relations for free-fermion and Ising models
DOE Office of Scientific and Technical Information (OSTI.GOV)
Davies, B.
1987-02-01
Eight-vertex, free fermion, and Ising models are formulated using a convention that emphasizes the algebra of the local transition operators that arise in the quantum inverse method. Equivalent classes of models, are investigated, with particular emphasis on the role of the star-triangle relations. Using these results, a natural and symmetrical parametrization is introduced and Yang-Baxter relations are constructed in an elementary way. The paper concludes with a consideration of duality, which links the present work to a recent paper of Baxter on the free fermion model.
Trust Relationships, Naming, and Secure Communication In Large Distributed Computer Systems
1988-09-01
Hemek, Harry Rubin, Keshav Srinivasan, Mark Sullivan, Dinesh Verma and Songnian Zhou for their friend- ship and help. I cannot think of a more dynamic...parents, Nagarathnamma and Prasanna Kumar , who are models of perfection in every walk of life, whose teaching and training have brought me where I...the driving force through out my life. My brother, Sreerang Rajan, has been a source of wisdom, and, my little brother, Srihari Sampath Kumar , has
NASA Astrophysics Data System (ADS)
Núñez, Alvaro; Starinets, Andrei O.
2003-06-01
We use the Lorentzian AdS/CFT prescription to find the poles of the retarded thermal Green’s functions of N=4 SU(N) supersymmetric Yang-Mills theory in the limit of large N and large ’t Hooft coupling. In the process, we propose a natural definition for quasinormal modes in an asymptotically AdS spacetime, with boundary conditions dictated by the AdS/CFT correspondence. The corresponding frequencies determine the dispersion laws for the quasiparticle excitations in the dual finite-temperature gauge theory. Correlation functions of operators dual to massive scalar, vector and gravitational perturbations in a five-dimensional AdS-Schwarzschild background are considered. We find asymptotic formulas for quasinormal frequencies in the massive scalar and tensor cases, and an exact expression for vector perturbations. In the long-distance, low-frequency limit we recover results of the hydrodynamic approximation to thermal Yang-Mills theory.
Step scaling and the Yang-Mills gradient flow
NASA Astrophysics Data System (ADS)
Lüscher, Martin
2014-06-01
The use of the Yang-Mills gradient flow in step-scaling studies of lattice QCD is expected to lead to results of unprecedented precision. Step scaling is usually based on the Schrödinger functional, where time ranges over an interval [0 , T] and all fields satisfy Dirichlet boundary conditions at time 0 and T. In these calculations, potentially important sources of systematic errors are boundary lattice effects and the infamous topology-freezing problem. The latter is here shown to be absent if Neumann instead of Dirichlet boundary conditions are imposed on the gauge field at time 0. Moreover, the expectation values of gauge-invariant local fields at positive flow time (and of other well localized observables) that reside in the center of the space-time volume are found to be largely insensitive to the boundary lattice effects.
Nonlocal symmetries and Bäcklund transformations for the self-dual Yang-Mills system
NASA Astrophysics Data System (ADS)
Papachristou, C. J.; Harrison, B. Kent
1988-01-01
The observation is made that generalized evolutionary isovectors of the self-dual Yang-Mills equation, obtained by ``verticalization'' of the geometrical isovectors derived in a previous paper [J. Math. Phys. 28, 1261 (1987)], generate Bäcklund transformations for the self-dual system. In particular, new Bäcklund transformations are obtained by ``verticalizing'' the generators of point transformations on the solution manifold. A geometric ansatz for the derivation of such (generally nonlocal) symmetries is proposed.
Cluster Adjacency Properties of Scattering Amplitudes in N =4 Supersymmetric Yang-Mills Theory
NASA Astrophysics Data System (ADS)
Drummond, James; Foster, Jack; Gürdoǧan, Ömer
2018-04-01
We conjecture a new set of analytic relations for scattering amplitudes in planar N =4 super Yang-Mills theory. They generalize the Steinmann relations and are expressed in terms of the cluster algebras associated to Gr (4 ,n ). In terms of the symbol, they dictate which letters can appear consecutively. We study heptagon amplitudes and integrals in detail and present symbols for previously unknown integrals at two and three loops which support our conjecture.
The Yin and Yang of YY1 in the nervous system
He, Ye; Casaccia-Bonnefil, Patrizia
2008-01-01
The transcription factor Yin Yang 1 (YY1) is a multifunctional protein that can activate or repress gene expression depending on the cellular context. YY1 is ubiquitously expressed and highly conserved between species. However its role varies in diverse cell types and includes proliferation, differentiation and apoptosis. This review will focus on the function of YY1 in the nervous system including its role in neural development, neuronal function, developmental myelination and neurological disease. The multiple functions of YY1 in distinct cell types are reviewed and the possible mechanisms underlying the cell specificity for these functions are discussed. PMID:18485096
Gravitational matter-antimatter asymmetry and four-dimensional Yang-Mills gauge symmetry
NASA Technical Reports Server (NTRS)
Hsu, J. P.
1981-01-01
A formulation of gravity based on the maximum four-dimensional Yang-Mills gauge symmetry is studied. The theory predicts that the gravitational force inside matter (fermions) is different from that inside antimatter. This difference could lead to the cosmic separation of matter and antimatter in the evolution of the universe. Moreover, a new gravitational long-range spin-force between two fermions is predicted, in addition to the usual Newtonian force. The geometrical foundation of such a gravitational theory is the Riemann-Cartan geometry, in which there is a torsion. The results of the theory for weak fields are consistent with previous experiments.
Supersymmetric Yang-Mills theory on conformal supergravity backgrounds in ten dimensions
NASA Astrophysics Data System (ADS)
de Medeiros, Paul; Figueroa-O'Farrill, José
2016-03-01
We consider bosonic supersymmetric backgrounds of ten-dimensional conformal supergravity. Up to local conformal isometry, we classify the maximally supersymmetric backgrounds, determine their conformal symmetry superalgebras and show how they arise as near-horizon geometries of certain half-BPS backgrounds or as a plane-wave limit thereof. We then show how to define Yang-Mills theory with rigid supersymmetry on any supersymmetric conformal supergravity background and, in particular, on the maximally supersymmetric backgrounds. We conclude by commenting on a striking resemblance between the supersymmetric backgrounds of ten-dimensional conformal supergravity and those of eleven-dimensional Poincaré supergravity.
NASA Astrophysics Data System (ADS)
Burban, Igor; Galinat, Lennart; Stolin, Alexander
2017-11-01
In this paper we study the combinatorics of quasi-trigonometric solutions of the classical Yang-Baxter equation, arising from simple vector bundles on a nodal Weierstraß cubic. Dedicated to the memory of Petr Petrovich Kulish.
Wang, Bo; Liu, Xiru; Hu, Zhihai; Sun, Aijun; Ma, Yanwen; Chen Yingying; Zhang, Xuzhi; Liu, Meiling; Wang, Yi; Wang, Shuoshuo; Zhang, Yunjia; Li, Yijing; Shen, Weidong
2016-02-01
To evaluate the clinical efficacy of YANG's pricking-cupping therapy for knee osteoar thritis (KOA). Methods This was a multi-center randomized parallel controlled trial. One hundred and seventy one patients with KOA were randomly allocated to a pricking-cupping group (89 cases) and a conventional acu puncture group (82 cases). Neixiyan (EX-LE 4), Dubi (ST 35) and ashi points were selected in the two groups. Patients in the pricking-cupping group were treated with YANG's pricking-cupping therapy; the seven-star needles were used to perform pricking at acupoints, then cupping was used until slight bleeding was observed. Patients in the conventional acupuncture group were treated with semi-standardized filiform needle therapy. The treatment was given for 4 weeks (from a minimum of 5 times to a maximum of 10 times). The follow-up visit was 4 weeks. The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and the visual analogue scale (VAS) were adopted for the efficacy assessments. The pain score, stiffness score, physical function score and total score of WOMAC were all reduced after 4-week treatment and during follow-up visit in the two groups (all P<0. 0001). Except that the difference of stiffness score between the two groups was not significant after 4-week treatment (P>0. 05), each score and total score of WOMAC in the pricking-cupping group were lower than those in the conventional acupuncture group after 4-week treatment and during follow-up visit (P<0. 0001, P<0. 01). After 2-week treatment, 4-week treatment and during follow-up visit, the VAS was all reduced compared with that before treatment (all P<0. 0001) ; with the increase of the treatment, the reducing trend of VAS was more significant (P<0. 0001). The scores of VAS in the pricking-cupping group were lower than those in the conventional acupuncture group after 4-week treatment and during follow-up visit (P < 0. 01, P <0. 0001). CONCLUSION The YANG's pricking-cupping and conventional
Functional renormalization group approach to the Yang-Lee edge singularity
An, X.; Mesterházy, D.; Stephanov, M. A.
2016-07-08
Here, we determine the scaling properties of the Yang-Lee edge singularity as described by a one-component scalar field theory with imaginary cubic coupling, using the nonperturbative functional renormalization group in 3 ≤ d ≤ 6 Euclidean dimensions. We find very good agreement with high-temperature series data in d = 3 dimensions and compare our results to recent estimates of critical exponents obtained with the four-loop ϵ = 6 - d expansion and the conformal bootstrap. The relevance of operator insertions at the corresponding fixed point of the RG β functions is discussed and we estimate the error associated with O(∂more » 4) truncations of the scale-dependent effective action.« less
Classical and quantum aspects of Yang-Baxter Wess-Zumino models
NASA Astrophysics Data System (ADS)
Demulder, Saskia; Driezen, Sibylle; Sevrin, Alexander; Thompson, Daniel C.
2018-03-01
We investigate the integrable Yang-Baxter deformation of the 2d Principal Chiral Model with a Wess-Zumino term. For arbitrary groups, the one-loop β-functions are calculated and display a surprising connection between classical and quantum physics: the classical integrability condition is necessary to prevent new couplings being generated by renormalisation. We show these theories admit an elegant realisation of Poisson-Lie T-duality acting as a simple inversion of coupling constants. The self-dual point corresponds to the Wess-Zumino-Witten model and is the IR fixed point under RG. We address the possibility of having supersymmetric extensions of these models showing that extended supersymmetry is not possible in general.
Functional renormalization group approach to the Yang-Lee edge singularity
DOE Office of Scientific and Technical Information (OSTI.GOV)
An, X.; Mesterházy, D.; Stephanov, M. A.
Here, we determine the scaling properties of the Yang-Lee edge singularity as described by a one-component scalar field theory with imaginary cubic coupling, using the nonperturbative functional renormalization group in 3 ≤ d ≤ 6 Euclidean dimensions. We find very good agreement with high-temperature series data in d = 3 dimensions and compare our results to recent estimates of critical exponents obtained with the four-loop ϵ = 6 - d expansion and the conformal bootstrap. The relevance of operator insertions at the corresponding fixed point of the RG β functions is discussed and we estimate the error associated with O(∂more » 4) truncations of the scale-dependent effective action.« less
Solution to the nonlinear field equations of ten dimensional supersymmetric Yang-Mills theory
NASA Astrophysics Data System (ADS)
Mafra, Carlos R.; Schlotterer, Oliver
2015-09-01
In this paper, we present a formal solution to the nonlinear field equations of ten-dimensional super Yang-Mills theory. It is assembled from products of linearized superfields which have been introduced as multiparticle superfields in the context of superstring perturbation theory. Their explicit form follows recursively from the conformal field theory description of the gluon multiplet in the pure spinor superstring. Furthermore, superfields of higher-mass dimensions are defined and their equations of motion are spelled out.
The Effects of Yin, Yang and Qi in the Skin on Pain.
Adams, James David
2016-01-29
The most effective and safe treatment site for pain is in the skin. This chapter discusses the reasons to treat pain in the skin. Pain is sensed in the skin through transient receptor potential cation channels and other receptors. These receptors have endogenous agonists (yang) and antagonists (yin) that help the body control pain. Acupuncture works through modulation of these receptor activities (qi) in the skin; as do moxibustion and liniments. The treatment of pain in the skin has the potential to save many lives and improve pain therapy in most patients.
The Effects of Yin, Yang and Qi in the Skin on Pain
Adams, James David
2016-01-01
The most effective and safe treatment site for pain is in the skin. This chapter discusses the reasons to treat pain in the skin. Pain is sensed in the skin through transient receptor potential cation channels and other receptors. These receptors have endogenous agonists (yang) and antagonists (yin) that help the body control pain. Acupuncture works through modulation of these receptor activities (qi) in the skin; as do moxibustion and liniments. The treatment of pain in the skin has the potential to save many lives and improve pain therapy in most patients. PMID:28930115
On the stability of dyons and dyonic black holes in Einstein-Yang-Mills theory
NASA Astrophysics Data System (ADS)
Nolan, Brien C.; Winstanley, Elizabeth
2016-02-01
We investigate the stability of four-dimensional dyonic soliton and black hole solutions of {su}(2) Einstein-Yang-Mills theory in anti-de Sitter space. We prove that, in a neighbourhood of the embedded trivial (Schwarzschild-)anti-de Sitter solution, there exist non-trivial dyonic soliton and black hole solutions of the field equations which are stable under linear, spherically symmetric, perturbations of the metric and non-Abelian gauge field.
Research of Helium Isotopes in Taiwan: The Legacy of Dr. Tsanyao Frank Yang
NASA Astrophysics Data System (ADS)
Yang, Tsanyao Frank; Lan, Tefang; Lee, Hsiao-Fen; Fu, Ching-Chou; Chuang, Pei-Chuan; Hong, Wei-Li; Walia, Vivek; Chen, Hsuan-Wen; Wen, Hsin-Yi; Chen, Ai-Ti; Chen, Hsiao-Chi; Chiu, Chun-Ming; Cheng, Chun-Yuan; Wu, Nian-Ru; Cheng, Yu-Chen; Chuang, Jin-Lun; Kao, Li-Hsin; Chen, Cheng-Hong; Sano, Yuji
2016-04-01
Helium isotope systematics is a powerful proxy to distinguish fluid origins and conveys fruitful geological information. In the past several decades, this robust isotope systematics had offered pivotal knowledge on many key issues in Earth and planetary sciences. It revealed essential geological information of Taiwan as well. Taiwan is located on the junction of two subduction systems-Ryukyu Arc and Luzon Arc. The geotectonic setting is complex and intriguing. Dr. Tsanyao Frank Yang was the pioneer of gas geochemistry studies in Taiwan. He established the first gas geochemistry laboratory in National Taiwan University in 1998 and started exploring all possible research topics on and around this tectonic-active island. In the past two decades, his research covered volcanic/hydrothermal gas studies, volcanic activity monitoring, gas hydrate exploration, soil gas as a tool to locate fault traces, soil gas flux measurement, earthquake precursory, mud volcanoes, low-temperature geochronology and many more. He died of pancreas cancer in March 2015. He was a warm and enthusiastic mentor, a prolific scientist and a great friend. He will always be remembered. Here we present Dr. Yang's achievement on helium isotopes studies in Taiwan throughout his research career. We integrate all the research results from his team and summarize the observations. We will show the distribution of helium isotope ratios in Taiwan and its implications on tectonic settings.
Phase diagram of q-deformed Yang-Mills theory on S 2 at non-zero θ-angle
NASA Astrophysics Data System (ADS)
Okuyama, Kazumi
2018-04-01
We study the phase diagram of q-deformed Yang-Mills theory on S 2 at non-zero θ-angle using the exact partition function at finite N . By evaluating the exact partition function numerically, we find evidence for the existence of a series of phase transitions at non-zero θ-angle as conjectured in [hep-th/0509004
Improved results for the mass spectrum of N = 1 supersymmetric SU(3) Yang-Mills theory
NASA Astrophysics Data System (ADS)
Ali, Sajid; Bergner, Georg; Gerber, Henning; Giudice, Pietro; Kuberski, Simon; Münster, Gernot; Montvay, István; Piemonte, Stefano; Scior, Philipp
2018-03-01
This talk summarizes the results of the DESY-Münster collaboration for N = 1 supersymmetric Yang-Mills theory with the gauge group SU(3). It is an updated status report with respect to our preliminary data presented at the last conference. In order to control the lattice artefacts we have now considered a clover improved fermion action and different values of the gauge coupling.
A Study of the Yang-gyeong-gyu-il-ui (兩景揆日儀) in the Joseon Dynasty
NASA Astrophysics Data System (ADS)
Lee, Yong Sam; Kim, Sang Hyuk; Mihn, Byeong-Hee
2015-03-01
The Yang-gyeong-gyu-il-ui (兩景揆日儀) is a kind of elevation sundial using three wooden plates. Sang-hyeok Lee (李尙爀, 1810~?) and Byeong-cheol Nam (南秉哲, 1817~1863) gave descriptions of this sundial and explained how to use it in their Gyu-il-go (揆日考) and Ui-gi-jip-seol (儀器輯說), respectively. According to Gyu-il-go (揆日考) there are two horizontal plates and two vertical plates that have lines of season and time. Subseasonal (節候) lines are engraved between seasonal (節氣) lines, subdividing the interval into three equal lines of Cho-hu (初候, early subseason), Jung-hu (中候, mid subseason) and Mal-hu (末候, late subseason); there are 13 seasonal lines for a year, thus resulting in 37 subseasonal lines; also, there are 12 double-hour (時辰) lines for a day engraved on these plates. The only remaining artifact of Yang-gyeong-gyu-il-ui was made in 1849 (the 15th year of Heon-jong) and is kept at the Korea University Museum. We have compared and analyzed Yanggyeong- gyu-il-ui and similar western sundials. Also, we have reviewed the scientific aspect of this artifact and built a replica. Yang-gyeong-gyu-il-ui is a new model enhanced from the miniaturization development in the early Joseon Dynasty and can be applied to the southern part of the tropic line through a structure change.
Pure spinor superspace action for D = 6, N = 1 super-Yang-Mills theory
NASA Astrophysics Data System (ADS)
Cederwall, Martin
2018-05-01
A Batalin-Vilkovisky action for D = 6, N = 1 super-Yang-Mills theory, including coupling to hypermultiplets, is given. The formalism involves pure spinor superfields. The geometric properties of the D = 6, N = 1 pure spinors (which differ from Cartan pure spinors) are examined. Unlike the situation for maximally supersymmetric models, the fields and antifields (including ghosts) of the vector multiplet reside in separate superfields. The formalism provides an off-shell superspace formulation for matter hypermultiplets, which in a traditional treatment are on-shell.
The Oncogenic Role of Yin Yang 1
Zhang, Qiang; Stovall, Daniel B.; Inoue, Kazushi; Sui, Guangchao
2012-01-01
Yin Yang 1 (YY1) is a transcription factor with diverse and complex biological functions. YY1 either activates or represses gene transcription, depending on the stimuli received by the cells and its association with other cellular factors. Since its discovery, a biological role for YY1 in tumor development and progression has been suggested because of its regulatory activities toward multiple cancer-related proteins and signaling pathways and its overexpression in most cancers. In this review, we primarily focus on YY1 studies in cancer research, including the regulation of YY1 as a transcription factor, its activities independent of its DNA binding ability, the functions of its associated proteins, and mechanisms regulating YY1 expression and activities. We also discuss the correlation of YY1 expression with clinical outcomes of cancer patients and its target potential in cancer therapy. Although there is not a complete consensus about the role of YY1 in cancers based on its activities of regulating oncogene and tumor suppressor expression, most of the currently available evidence supports a proliferative or oncogenic role of YY1 in tumorigenesis. PMID:22248053
NASA Astrophysics Data System (ADS)
Elvis, M.; Murdin, P.
2002-10-01
Launched on 23 July 1999 on board the SpaceShuttle Columbia from Cape Canaveral, the ChandraX-ray Observatory is the first x-ray astronomytelescope to match the 1/2 arcsecond imagingpower and the 0.1% spectral resolving power ofoptical telescopes. Chandra is named afterSubramanian Chandrasekhar, known as Chandra, andauthor of the Chandrasekhar limit. Chandra hasbeen extremely successful and produc...
Complexion of forces in an anisotropic self-gravitating system
DOE Office of Scientific and Technical Information (OSTI.GOV)
Kandrup, H.E.
Chandrasekhar and von Neumann developed a completely stochastic formalism to analyze the complexion of forces acting upon a test star situated in an infinite, homogeneous distribution of field stars. This formalism is generalized here to allow for more realistic inhomogeneous and anisotropic systems. It is demonstrated that the forces acting upon a test star decompose ''naturally'' into the incoherent sum of a mean force associated with the average spatial inhomogeneity and a fluctuating force associated with stochastic deviations from these mean conditions. Moreover, as in the special case considered by Chandrasekhar and von Neumann, one can apparently associate the fluctuatingmore » forces with the effects of particularly proximate field stars, thereby motivating the ''nearest neighbor'' interpretation first introduced by Chandrasekhar.« less
NASA Astrophysics Data System (ADS)
Starrfield, Sumner; Bose, Maitrayee; Iliadis, Christian; Hix, William R.; Wagner, R. Mark; Woodward, Charles E.; Jose', Jordi; Hernanz, Margarita
2018-01-01
We have continued our studies of Classical Nova explosions by following the evolution of thermonuclear runaways (TNRs) on Carbon Oxygen white dwarfs (WDs). We have varied both the mass of the WD and the composition of the accreted material. We now rely on the results of multi-D studies of TNRs in WDs that accrete only Solar matter. They find that mixing with the core occurs after the TNR is well underway, reaching enrichment levels in agreement with observations of the ejecta abundances. We, therefore, accrete only Solar matter with NOVA (our 1-D, fully implicit, hydro code) until the TNR is initiated and then switch the accreted composition to a mixed composition: either 25% core and 75% Solar or 50% core and 50% Solar. Because the amount of accreted material is inversely proportional to the initial 12C abundance, by accreting Solar matter the amount of material taking part in the outburst is larger than if we had used mixed material from the beginning. We follow the TNR through the peak and tabulate the amount of ejected gases, their velocities and abundances. We also predict the amount of 7Li and 7Be produced and ejected by the explosion and compare our predictions to the observations in a companion poster describing the LBT measurements of 7Li in V5668 Sgr. We also compare our abundance predictions to those measured in pre-solar grains that may arise from Classical Nova explosions. Our predictions are also compared to results with SHIVA (Josè and Hernanz). Finally, many of these simulations eject significantly less mass than accreted and, therefore, the WD is growing in mass toward the Chandrasekhar Limit. This suggests that the single degenerate scenario is still a viable option for SN Ia progenitors. This work was supported in part by NASA under the Astrophysics Theory Program grant 14-ATP14-0007 and the U.S. DOE under Contract No. DE-FG02- 97ER41041. SS acknowledges partial support from NASA and HST grants to ASU and WRH is supported by the U.S. Department
Gravitational catalysis of merons in Einstein-Yang-Mills theory
NASA Astrophysics Data System (ADS)
Canfora, Fabrizio; Oh, Seung Hun; Salgado-Rebolledo, Patricio
2017-10-01
We construct regular configurations of the Einstein-Yang-Mills theory in various dimensions. The gauge field is of meron-type: it is proportional to a pure gauge (with a suitable parameter λ determined by the field equations). The corresponding smooth gauge transformation cannot be deformed continuously to the identity. In the three-dimensional case we consider the inclusion of a Chern-Simons term into the analysis, allowing λ to be different from its usual value of 1 /2 . In four dimensions, the gravitating meron is a smooth Euclidean wormhole interpolating between different vacua of the theory. In five and higher dimensions smooth meron-like configurations can also be constructed by considering warped products of the three-sphere and lower-dimensional Einstein manifolds. In all cases merons (which on flat spaces would be singular) become regular due to the coupling with general relativity. This effect is named "gravitational catalysis of merons".
FLRW Cosmology from Yang-Mills Gravity with Translational Gauge Symmetry
NASA Astrophysics Data System (ADS)
Katz, Daniel
2013-03-01
We extend to basic cosmology the subject of Yang-Mills gravity — a theory of gravity based on local translational gauge invariance in flat space-time. It has been shown that this particular gauge invariance leads to tensor factors in the macroscopic limit of the equations of motion of particles which plays the same role as the metric tensor of general relativity (GR). The assumption that this "effective metric" tensor takes on the standard FLRW form is our starting point. Equations analogous to the Friedmann equations are derived and then solved in closed form for the three special cases of a universe dominated by (1) matter, (2) radiation and (3) dark energy. We find that the solutions for the scale factor are similar to, but distinct from, those found in the corresponding GR based treatment.
Yang-Baxter algebras, integrable theories and Bethe Ansatz
DOE Office of Scientific and Technical Information (OSTI.GOV)
De Vega, H.J.
1990-03-10
This paper presents the Yang-Baxter algebras (YBA) in a general framework stressing their power to exactly solve the lattice models associated to them. The algebraic Behe Ansatz is developed as an eigenvector construction based on the YBA. The six-vertex model solution is given explicitly. The generalization of YB algebras to face language is considered. The algebraic BA for the SOS model of Andrews, Baxter and Forrester is described using these face YB algebras. It is explained how these lattice models yield both solvable massive QFT and conformal models in appropriated scaling (continuous) limits within the lattice light-cone approach. This approachmore » permit to define and solve rigorously massive QFT as an appropriate continuum limit of gapless vertex models. The deep links between the YBA and Lie algebras are analyzed including the quantum groups that underlay the trigonometric/hyperbolic YBA. Braid and quantum groups are derived from trigonometric/hyperbolic YBA in the limit of infinite spectral parameter. To conclude, some recent developments in the domain of integrable theories are summarized.« less
Infrared singularities in Landau gauge Yang-Mills theory
DOE Office of Scientific and Technical Information (OSTI.GOV)
Alkofer, Reinhard; Huber, Markus Q.; Schwenzer, Kai
2010-05-15
We present a more detailed picture of the infrared regime of Landau-gauge Yang-Mills theory. This is done within a novel framework that allows one to take into account the influence of finite scales within an infrared power counting analysis. We find that there are two qualitatively different infrared fixed points of the full system of Dyson-Schwinger equations. The first extends the known scaling solution, where the ghost dynamics is dominant and gluon propagation is strongly suppressed. It features in addition to the strong divergences of gluonic vertex functions in the previously considered uniform scaling limit, when all external momenta tendmore » to zero, also weaker kinematic divergences, when only some of the external momenta vanish. The second solution represents the recently proposed decoupling scenario where the gluons become massive and the ghosts remain bare. In this case we find that none of the vertex functions is enhanced, so that the infrared dynamics is entirely suppressed. Our analysis also provides a strict argument why the Landau-gauge gluon dressing function cannot be infrared divergent.« less
Solid waste management in Thailand: an overview and case study (Tha Khon Yang sub-district).
Yukalang, Nachalida; Clarke, Beverley Dawn; Ross, Kirstin Elizabeth
2017-09-26
Due to rapid urbanization, solid waste management (SWM) has become a significant issue in several developing countries including Thailand. Policies implemented by the Central Thai Government to manage SWM issues have had only limited success. This article reviews current municipal waste management plans in Thailand and examines municipal waste management at the local level, with focus on the Tha Khon Yang sub-district surrounding Mahasarakham University in Mahasarakham Province. Within two decades this area has been converted from a rural to an urban landscape featuring accommodation for over 45,000 university students and a range of business facilities. This development and influx of people has outpaced the government's ability to manage municipal solid waste (MSW). There are significant opportunities to improve local infrastructure and operational capacity; but there are few mechanisms to provide and distribute information to improve community participation in waste management. Many community-based waste management projects, such as waste recycling banks, the 3Rs (reduce, reuse and recycle), and waste-to-biogas projects have been abandoned. Additionally, waste from Tha Kon Yang and its surrounding areas has been transferred to unsanitary landfills; there is also haphazard dumping and uncontrolled burning of waste, which exacerbate current pollution issues.
Amplitudes in the N=4 supersymmetric Yang-Mills theory from quantum geometry of momentum space
DOE Office of Scientific and Technical Information (OSTI.GOV)
Gorsky, A.
We discuss multiloop maximally helicity violating amplitudes in the N=4 supersymmetric Yang-Mills theory in terms of effective gravity in the momentum space with IR regulator branes as degrees of freedom. Kinematical invariants of external particles yield the moduli spaces of complex or Kahler structures which are the playgrounds for the Kodaira-Spencer or Kahler type gravity. We suggest fermionic representation of the loop maximally helicity violating amplitudes in the N=4 supersymmetric Yang-Mills theory assuming the identification of the IR regulator branes with Kodaira-Spencer fermions in the B model and Lagrangian branes in the A model. The two-easy mass box diagram ismore » related to the correlator of fermionic currents on the spectral curve in the B model or hyperbolic volume in the A model and it plays the role of a building block in the whole picture. The Bern-Dixon-Smirnov-like ansatz has the interpretation as the semiclassical limit of a fermionic correlator. It is argued that fermionic representation implies a kind of integrability on the moduli spaces. We conjecture the interpretation of the reggeon degrees of freedom in terms of the open strings stretched between the IR regulator branes.« less
NASA Astrophysics Data System (ADS)
Balakin, Alexander B.; Lemos, José P. S.; Zayats, Alexei E.
2016-04-01
Alternative theories of gravity and their solutions are of considerable importance since, at some fundamental level, the world can reveal new features. Indeed, it is suspected that the gravitational field might be nonminimally coupled to the other fields at scales not yet probed, bringing into the forefront nonminimally coupled theories. In this mode, we consider a nonminimal Einstein-Yang-Mills theory with a cosmological constant. Imposing spherical symmetry and staticity for the spacetime and a magnetic Wu-Yang ansatz for the Yang-Mills field, we find expressions for the solutions of the theory. Further imposing constraints on the nonminimal parameters, we find a family of exact solutions of the theory depending on five parameters—two nonminimal parameters, the cosmological constant, the magnetic charge, and the mass. These solutions represent magnetic monopoles and black holes in magnetic monopoles with de Sitter, Minkowskian, and anti-de Sitter asymptotics, depending on the sign and value of the cosmological constant Λ . We classify completely the family of solutions with respect to the number and the type of horizons and show that the spacetime solutions can have, at most, four horizons. For particular sets of the parameters, these horizons can become double, triple, and quadruple. For instance, for a positive cosmological constant Λ , there is a critical Λc for which the solution admits a quadruple horizon, evocative of the Λc that appears for a given energy density in both the Einstein static and Eddington-Lemaître dynamical universes. As an example of our classification, we analyze solutions in the Drummond-Hathrell nonminimal theory that describe nonminimal black holes. Another application is with a set of regular black holes previously treated.
5D Super Yang-Mills on Y p, q Sasaki-Einstein Manifolds
NASA Astrophysics Data System (ADS)
Qiu, Jian; Zabzine, Maxim
2015-01-01
On any simply connected Sasaki-Einstein five dimensional manifold one can construct a super Yang-Mills theory which preserves at least two supersymmetries. We study the special case of toric Sasaki-Einstein manifolds known as Y p, q manifolds. We use the localisation technique to compute the full perturbative part of the partition function. The full equivariant result is expressed in terms of a certain special function which appears to be a curious generalisation of the triple sine function. As an application of our general result we study the large N behaviour for the case of single hypermultiplet in adjoint representation and we derive the N 3-behaviour in this case.
1999-07-19
KENNEDY SPACE CENTER, FLA. -- Mrs. Lalitha Chandrasekhar (left), wife of the late Indian-American Nobel Laureate Subrahmanyan Chandrasekhar, poses with a model of the Chandra X-ray Observatory and the winners of the contest to rename the telescope in the TRW Media Hospitality Tent at the NASA Press Site at KSC. The winners of the contest are Jatila van der Veen (center), academic coordinator and lecturer, Physics Dept., University of Santa Barbara, Calif., and Tyrel Johnson (right), high school student, Laclede, Idaho. The name "Chandra," a shortened version of Chandrasekhar's name which he preferred among friends and colleagues, was chosen to honor the Nobel Laureate. "Chandra" also means "Moon" or "luminous" in Sanskrit. The observatory is scheduled to be launched aboard Columbia on Space Shuttle mission STS-93
Duality-symmetric supersymmetric Yang-Mills theory in three dimensions
DOE Office of Scientific and Technical Information (OSTI.GOV)
Nishino, Hitoshi; Rajpoot, Subhash
We formulate a duality-symmetric N=1 supersymmetric Yang-Mills theory in three dimensions. Our field content is (A{sub {mu}}{sup I},{lambda}{sup I},{phi}{sup I}), where the index I is for the adjoint representation of an arbitrary gauge group G. Our Hodge duality symmetry is F{sub {mu}{nu}}{sup I}=+{epsilon}{sub {mu}{nu}}{sup {rho}D}{sub {rho}{phi}}{sup I}. Because of this relationship, the presence of two physical fields A{sub {mu}}{sup I} and {phi}{sup I} within the same N=1 supermultiplet poses no problem. We can couple this multiplet to another vector multiplet (C{sub {mu}}{sup I},{chi}{sup I};B{sub {mu}{nu}}{sup I}) with 1+1 physical degrees of freedom modulo dim G. Thanks to peculiar couplings andmore » supersymmetry, the usual problem with an extra vector field in a nontrivial representation does not arise in our system.« less
On non-primitively divergent vertices of Yang-Mills theory
NASA Astrophysics Data System (ADS)
Huber, Markus Q.
2017-11-01
Two correlation functions of Yang-Mills beyond the primitively divergent ones, the two-ghost-two-gluon and the four-ghost vertices, are calculated and their influence on lower vertices is examined. Their full (transverse) tensor structure is taken into account. As input, a solution of the full two-point equations - including two-loop terms - is used that respects the resummed perturbative ultraviolet behavior. A clear hierarchy is found with regard to the color structure that reduces the number of relevant dressing functions. The impact of the two-ghost-two-gluon vertex on the three-gluon vertex is negligible, which is explained by the fact that all non-small dressing functions drop out due to their color factors. Only in the ghost-gluon vertex a small net effect below 2% is seen. The four-ghost vertex is found to be extremely small in general. Since these two four-point functions do not enter into the propagator equations, these findings establish their small overall effect on lower correlation functions.
Yin and Yang of ginseng pharmacology: ginsenosides vs gintonin
Im, Dong-soon; Nah, Seung-yeol
2013-01-01
Ginseng, the root of Panax ginseng, has been used in traditional Chinese medicine as a tonic herb that provides many beneficial effects. Pharmacologic studies in the last decades have shown that ginsenosides (ginseng saponins) are primarily responsible for the actions of ginseng. However, the effects of ginseng are not fully explained by ginsenosides. Recently, another class of active ingredients called gintonin was identified. Gintonin is a complex of glycosylated ginseng proteins containing lysophosphatidic acids (LPAs) that are the intracellular lipid mitogenic mediator. Gintonin specifically and potently activates the G protein-coupled receptors (GPCRs) for LPA. Thus, the actions of ginseng are now also linked to LPA and its GPCRs. This linkage opens new dimensions for ginseng pharmacology and LPA therapeutics. In the present review, we evaluate the pharmacology of ginseng with the traditional viewpoint of Yin and Yang components. Furthermore, we will compare ginsenoside and gintonin based on the modern view of molecular pharmacology in terms of ion channels and GPCRs. PMID:24122014
A non-symmetric Yang-Baxter algebra for the quantum nonlinear Schrödinger model
NASA Astrophysics Data System (ADS)
Vlaar, Bart
2013-06-01
We study certain non-symmetric wavefunctions associated with the quantum nonlinear Schrödinger model, introduced by Komori and Hikami using Gutkin’s propagation operator, which involves representations of the degenerate affine Hecke algebra. We highlight how these functions can be generated using a vertex-type operator formalism similar to the recursion defining the symmetric (Bethe) wavefunction in the quantum inverse scattering method. Furthermore, some of the commutation relations encoded in the Yang-Baxter equation for the relevant monodromy matrix are generalized to the non-symmetric case.
The light bound states of N=1 supersymmetric SU(3) Yang-Mills theory on the lattice
NASA Astrophysics Data System (ADS)
Ali, Sajid; Bergner, Georg; Gerber, Henning; Giudice, Pietro; Montvay, Istvan; Münster, Gernot; Piemonte, Stefano; Scior, Philipp
2018-03-01
In this article we summarise our results from numerical simulations of N=1 supersymmetric Yang-Mills theory with gauge group SU(3). We use the formulation of Curci and Veneziano with clover-improved Wilson fermions. The masses of various bound states have been obtained at different values of the gluino mass and gauge coupling. Extrapolations to the limit of vanishing gluino mass indicate that the bound states form mass-degenerate supermultiplets.
Composite operator and condensate in the S U (N ) Yang-Mills theory with U (N -1 ) stability group
NASA Astrophysics Data System (ADS)
Warschinke, Matthias; Matsudo, Ryutaro; Nishino, Shogo; Shinohara, Toru; Kondo, Kei-Ichi
2018-02-01
Recently, some reformulations of the Yang-Mills theory inspired by the Cho-Faddeev-Niemi decomposition have been developed in order to understand confinement from the viewpoint of the dual superconductivity. In this paper we focus on the reformulated S U (N ) Yang-Mills theory in the minimal option with U (N -1 ) stability group. Despite existing numerical simulations on the lattice we perform the perturbative analysis to one-loop level as a first step towards the nonperturbative analytical treatment. First, we give the Feynman rules and calculate all renormalization factors to obtain the standard renormalization group functions to one-loop level in light of the renormalizability of this theory. Then we introduce a mixed gluon-ghost composite operator of mass dimension 2 and show the Bechi-Rouet-Stora-Tyutin invariance and the multiplicative renormalizability. Armed with these results, we argue the existence of the mixed gluon-ghost condensate by means of the so-called local composite operator formalism, which leads to various interesting implications for confinement as shown in preceding works.
NASA Astrophysics Data System (ADS)
Matsudo, Ryutaro; Kondo, Kei-Ichi; Shibata, Akihiro
2018-03-01
We examine how the average of double-winding Wilson loops depends on the number of color N in the SU(N) Yang-Mills theory. In the case where the two loops C1 and C2 are identical, we derive the exact operator relation which relates the doublewinding Wilson loop operator in the fundamental representation to that in the higher dimensional representations depending on N. By taking the average of the relation, we find that the difference-of-areas law for the area law falloff recently claimed for N = 2 is excluded for N ⩾ 3, provided that the string tension obeys the Casimir scaling for the higher representations. In the case where the two loops are distinct, we argue that the area law follows a novel law (N - 3)A1/(N - 1) + A2 with A1 and A2(A1 < A2) being the minimal areas spanned respectively by the loops C1 and C2, which is neither sum-ofareas (A1 + A2) nor difference-of-areas (A2 - A1) law when (N ⩾ 3). Indeed, this behavior can be confirmed in the two-dimensional SU(N) Yang-Mills theory exactly.
Finite-volume spectra of the Lee-Yang model
NASA Astrophysics Data System (ADS)
Bajnok, Zoltan; el Deeb, Omar; Pearce, Paul A.
2015-04-01
We consider the non-unitary Lee-Yang minimal model in three different finite geometries: (i) on the interval with integrable boundary conditions labelled by the Kac labels ( r, s) = (1 , 1) , (1 , 2), (ii) on the circle with periodic boundary conditions and (iii) on the periodic circle including an integrable purely transmitting defect. We apply φ 1,3 integrable perturbations on the boundary and on the defect and describe the flow of the spectrum. Adding a Φ1,3 integrable perturbation to move off-criticality in the bulk, we determine the finite size spectrum of the massive scattering theory in the three geometries via Thermodynamic Bethe Ansatz (TBA) equations. We derive these integral equations for all excitations by solving, in the continuum scaling limit, the TBA functional equations satisfied by the transfer matrices of the associated A 4 RSOS lattice model of Forrester and Baxter in Regime III. The excitations are classified in terms of ( m, n) systems. The excited state TBA equations agree with the previously conjectured equations in the boundary and periodic cases. In the defect case, new TBA equations confirm previously conjectured transmission factors.
Parallel software for lattice N = 4 supersymmetric Yang-Mills theory
NASA Astrophysics Data System (ADS)
Schaich, David; DeGrand, Thomas
2015-05-01
We present new parallel software, SUSY LATTICE, for lattice studies of four-dimensional N = 4 supersymmetric Yang-Mills theory with gauge group SU(N). The lattice action is constructed to exactly preserve a single supersymmetry charge at non-zero lattice spacing, up to additional potential terms included to stabilize numerical simulations. The software evolved from the MILC code for lattice QCD, and retains a similar large-scale framework despite the different target theory. Many routines are adapted from an existing serial code (Catterall and Joseph, 2012), which SUSY LATTICE supersedes. This paper provides an overview of the new parallel software, summarizing the lattice system, describing the applications that are currently provided and explaining their basic workflow for non-experts in lattice gauge theory. We discuss the parallel performance of the code, and highlight some notable aspects of the documentation for those interested in contributing to its future development.
Regge meets collinear in strongly-coupled N=4 super Yang-Mills
NASA Astrophysics Data System (ADS)
Sprenger, Martin
2017-01-01
We revisit the calculation of the six-gluon remainder function in planar N=4 super Yang-Mills theory from the strong coupling TBA in the multi-Regge limit and identify an infinite set of kinematically subleading terms. These new terms can be compared to the strong coupling limit of the finite-coupling expressions for the impact factor and the BFKL eigenvalue proposed by Basso et al. in [1], which were obtained from an analytic continuation of the Wilson loop OPE. After comparing the results order by order in those subleading terms, we show that it is possible to precisely map both formalisms onto each other. A similar calculation can be carried out for the seven-gluon amplitude, the result of which shows that the central emission vertex does not become trivial at strong coupling.
The category of Yetter-Drinfel'd Hom-modules and the quantum Hom-Yang-Baxter equation
DOE Office of Scientific and Technical Information (OSTI.GOV)
Chen, Yuanyuan; Zhang, Liangyun, E-mail: zlyun@njau.edu.cn
2014-03-15
In this paper, we introduce the category of Yetter-Drinfel'd Hom-modules which is a braided monoidal category and show that the category of Yetter-Drinfel'd Hom-modules is a full monoidal subcategory of the left center of left Hom-module category. Also we study the equivalent relationship between the category of Yetter-Drinfel'd Hom-modules and the category of Hom-modules over the Drinfel'd double. Finally, the Faddeev-Reshetikhin-Takhtajan (FRT) type theorem for the quantum Hom-Yang-Baxter equation is investigated.
ERIC Educational Resources Information Center
White, Jennifer
2009-01-01
The exploratory study conducted by Yang, Burrola, and Bryan (2009) provides an excellent platform for calling attention to the issue of suicide risk among elementary and middle school youth. Using their study as a catalyst, with this commentary I consider the finding that 12% of the young people surveyed acknowledged that they had "seriously…
From decay to complete breaking: pulling the strings in SU(2) Yang-Mills theory.
Pepe, M; Wiese, U-J
2009-05-15
We study {2Q+1} strings connecting two static charges Q in (2+1)D SU(2) Yang-Mills theory. While the fundamental {2} string between two charges Q=1/2 is unbreakable, the adjoint {3} string connecting two charges Q=1 can break. When a {4} string is stretched beyond a critical length, it decays into a {2} string by gluon pair creation. When a {5} string is stretched, it first decays into a {3} string, which eventually breaks completely. The energy of the screened charges at the ends of a string is well described by a phenomenological constituent gluon model.
Integrability in dipole-deformed \\boldsymbol{N=4} super Yang-Mills
NASA Astrophysics Data System (ADS)
Guica, Monica; Levkovich Maslyuk, Fedor; Zarembo, Konstantin
2017-09-01
We study the null dipole deformation of N=4 super Yang-Mills theory, which is an example of a potentially solvable ‘dipole CFT’: a theory that is non-local along a null direction, has non-relativistic conformal invariance along the remaining ones, and is holographically dual to a Schrödinger space-time. We initiate the field-theoretical study of the spectrum in this model by using integrability inherited from the parent theory. The dipole deformation corresponds to a nondiagonal Drinfeld-Reshetikhin twist in the spin chain picture, which renders the traditional Bethe ansatz inapplicable from the very beginning. We use instead the Baxter equation supplemented with nontrivial asymptotics, which gives the full 1-loop spectrum in the sl(2) sector. We show that anomalous dimensions of long gauge theory operators perfectly match the string theory prediction, providing a quantitative test of Schrödinger holography. Dedicated to the memory of Petr Petrovich Kulish.
Hydrodynamics of the Polyakov line in SU(N c) Yang-Mills
Liu, Yizhuang; Warchoł, Piotr; Zahed, Ismail
2015-12-08
We discuss a hydrodynamical description of the eigenvalues of the Polyakov line at large but finite N c for Yang-Mills theory in even and odd space-time dimensions. The hydro-static solutions for the eigenvalue densities are shown to interpolate between a uniform distribution in the confined phase and a localized distribution in the de-confined phase. The resulting critical temperatures are in overall agreement with those measured on the lattice over a broad range of N c, and are consistent with the string model results at N c = ∞. The stochastic relaxation of the eigenvalues of the Polyakov line out ofmore » equilibrium is captured by a hydrodynamical instanton. An estimate of the probability of formation of a Z(N c)bubble using a piece-wise sound wave is suggested.« less
Yang-Mills instantons in Kähler spaces with one holomorphic isometry
NASA Astrophysics Data System (ADS)
Chimento, Samuele; Ortín, Tomás; Ruipérez, Alejandro
2018-03-01
We consider self-dual Yang-Mills instantons in 4-dimensional Kähler spaces with one holomorphic isometry and show that they satisfy a generalization of the Bogomol'nyi equation for magnetic monopoles on certain 3-dimensional metrics. We then search for solutions of this equation in 3-dimensional metrics foliated by 2-dimensional spheres, hyperboloids or planes in the case in which the gauge group coincides with the isometry group of the metric (SO(3), SO (1 , 2) and ISO(2), respectively). Using a generalized hedgehog ansatz the Bogomol'nyi equations reduce to a simple differential equation in the radial variable which admits a universal solution and, in some cases, a particular one, from which one finally recovers instanton solutions in the original Kähler space. We work out completely a few explicit examples for some Kähler spaces of interest.
USDA-ARS?s Scientific Manuscript database
Male and female Spathius agrili Yang were tested for attraction to the synthetic male pheromone. Lures consisting of a 3-component pheromone blend were placed in the center of a white filter paper target used to activate upwind flight in the wind tunnel. When virgin males and females were tested for...
Magnetic monopole in noncommutative space-time and Wu-Yang singularity-free gauge transformations
DOE Office of Scientific and Technical Information (OSTI.GOV)
Laangvik, Miklos; Salminen, Tapio; Tureanu, Anca
2011-04-15
We investigate the validity of the Dirac quantization condition for magnetic monopoles in noncommutative space-time. We use an approach which is based on an extension of the method introduced by Wu and Yang. To study the effects of noncommutativity of space-time, we consider the gauge transformations of U{sub *}(1) gauge fields and use the corresponding deformed Maxwell's equations. Using a perturbation expansion in the noncommutativity parameter {theta}, we show that the Dirac quantization condition remains unmodified up to the first order in the expansion parameter. The result is obtained for a class of noncommutative source terms, which reduce to themore » Dirac delta function in the commutative limit.« less
String tensions in deformed Yang-Mills theory
NASA Astrophysics Data System (ADS)
Poppitz, Erich; Shalchian T., M. Erfan
2018-01-01
We study k-strings in deformed Yang-Mills (dYM) with SU(N) gauge group in the semiclassically calculable regime on R^3× S^1 . Their tensions Tk are computed in two ways: numerically, for 2 ≤ N ≤ 10, and via an analytic approach using a re-summed perturbative expansion. The latter serves both as a consistency check on the numerical results and as a tool to analytically study the large-N limit. We find that dYM k-string ratios Tk/T1 do not obey the well-known sine- or Casimir-scaling laws. Instead, we show that the ratios Tk/T1 are bound above by a square root of Casimir scaling, previously found to hold for stringlike solutions of the MIT Bag Model. The reason behind this similarity is that dYM dynamically realizes, in a theoretically controlled setting, the main model assumptions of the Bag Model. We also compare confining strings in dYM and in other four-dimensional theories with abelian confinement, notably Seiberg-Witten theory, and show that the unbroken Z_N center symmetry in dYM leads to different properties of k-strings in the two theories; for example, a "baryon vertex" exists in dYM but not in softly-broken Seiberg-Witten theory. Our results also indicate that, at large values of N, k-strings in dYM do not become free.
Quasi-local energy in presence of gravitational radiation
NASA Astrophysics Data System (ADS)
Chen, Po-Ning; Wang, Mu-Tao; Yau, Shing-Tung
2016-07-01
We discuss our recent work [P.-N. Chen, M.-T. Wang and S.-T. Yau, Quasi-local mass in the gravitational perturbations of black holes, to appear.] in which gravitational radiation was studied by evaluating the Wang-Yau quasi-local mass of surfaces of fixed size at the infinity of both axial and polar perturbations of the Schwarzschild spacetime, à la Chandrasekhar. [S. Chandrasekhar, The Mathematical Theory of Black Holes, Oxford Classic Texts in the Physical Sciences (Oxford University Press, New York, 1998).
The universal character of Zwanziger's horizon function in Euclidean Yang-Mills theories
NASA Astrophysics Data System (ADS)
Capri, M. A. L.; Dudal, D.; Guimaraes, M. S.; Pereira, A. D.; Mintz, B. W.; Palhares, L. F.; Sorella, S. P.
2018-06-01
In light of the recently established BRST invariant formulation of the Gribov-Zwanziger theory, we show that Zwanziger's horizon function displays a universal character. More precisely, the correlation functions of local BRST invariant operators evaluated with the Yang-Mills action supplemented with a BRST invariant version of the Zwanziger's horizon function and quantized in an arbitrary class of covariant, color invariant and renormalizable gauges which reduce to the Landau gauge when all gauge parameters are set to zero, have a unique, gauge parameters independent result, corresponding to that of the Landau gauge when the restriction to the Gribov region Ω in the latter gauge is imposed. As such, thanks to the BRST invariance, the cut-off at the Gribov region Ω acquires a gauge independent meaning in the class of the physical correlators.
Lei, Bei; Cao, Jie; Shen, Jie; Zhao, Lanxiang; Liang, Sheng; Meng, Qinggang; Xie, Wenhui; Yang, Shunfang
2013-08-20
Lung cancer is the leading cause of cancer-related death in men and women. It is also the most common cause of brain metastases. A brain metastasis model is difficult to be established because of the presence of the blood-brain barrier (BBB) and the lack of optimal methods for detecting brain metastasis in nude mice. Thus, the establishment of a Chinese lung adenocarcinoma cell line and its animal model with brain metastasis potency and in vivo research is of great significance. CPA-Yang1 cells were obtained from a patient with human lung adenocarcinoma by lentiviral vector-mediated transfection of green fluorescence protein. Intracardiac inoculation of the cells was performed in nude mice, and brain metastatic lesions were detected using micro ¹⁸F FDG-PET/CT scanners, small animal in vivo imaging system for fluorescence, radionuclide and X ray fused imaging, magnetic resonance imaging (MRI) with sense body detection, and resection. The samples were divided into two parts for cell culture and histological diagnosis. The process was repeated in vivo and in vitro for four cycles to obtain a novel cell clone, CPA-Yang1-BR. A novel cell clone, CPA-Yang1-BR, was obtained with a brain metastatic rate of 50%. The use of MRI for the detection of brain metastases has obvious advantages. An experimental Chinese lung adenocarcinoma cell clone (CPA-Yang1-BR) and its animal model with brain metastasis potency in nude mice were established. MRI with sense body or micro MRI may be used as a sensitive, accurate, and noninvasive method to detect experimental brain metastases in intact live immunodeficient mice. The results of this study may serve as a technical platform for brain metastases from lung adenocarcinoma.
Hadamard States for the Linearized Yang-Mills Equation on Curved Spacetime
NASA Astrophysics Data System (ADS)
Gérard, C.; Wrochna, M.
2015-07-01
We construct Hadamard states for the Yang-Mills equation linearized around a smooth, space-compact background solution. We assume the spacetime is globally hyperbolic and its Cauchy surface is compact or equal . We first consider the case when the spacetime is ultra-static, but the background solution depends on time. By methods of pseudodifferential calculus we construct a parametrix for the associated vectorial Klein-Gordon equation. We then obtain Hadamard two-point functions in the gauge theory, acting on Cauchy data. A key role is played by classes of pseudodifferential operators that contain microlocal or spectral type low-energy cutoffs. The general problem is reduced to the ultra-static spacetime case using an extension of the deformation argument of Fulling, Narcowich and Wald. As an aside, we derive a correspondence between Hadamard states and parametrices for the Cauchy problem in ordinary quantum field theory.
Nucleosynthesis of Iron-Peak Elements in Type-Ia Supernovae
NASA Astrophysics Data System (ADS)
Leung, Shing-Chi; Nomoto, Ken'ichi
The observed features of typical Type Ia supernovae are well-modeled as the explosions of carbon-oxygen white dwarfs both near Chandrasekhar mass and sub-Chandrasekhar mass. However, observations in the last decade have shown that Type Ia supernovae exhibit a wide diversity, which implies models for wider range of parameters are necessary. Based on the hydrodynamics code we developed, we carry out a parameter study of Chandrasekhar mass models for Type Ia supernovae. We conduct a series of two-dimensional hydrodynamics simulations of the explosion phase using the turbulent flame model with the deflagration-detonation-transition (DDT). To reconstruct the nucleosynthesis history, we use the particle tracer scheme. We examine the role of model parameters by examining their influences on the final product of nucleosynthesis. The parameters include the initial density, metallicity, initial flame structure, detonation criteria and so on. We show that the observed chemical evolution of galaxies can help constrain these model parameters.
Note on the coupled oscillator model solutions in crystalline optical activity
NASA Astrophysics Data System (ADS)
Vyšín, I.; Ríha, J.; Svácková, K.
2006-06-01
Many methods have been used in the crystalline optical activity solution, among them the traditional method of coupled oscillators. The two coupled oscillator model was first solved by Chandrasekhar, and the most general dispersion relations for the crystalline optical activity can be obtained from its next extensions. However, the Chandrasekhar solution method seems to be based on a mistake in the computations. For this reason, the solution of a more complicated model of coupled oscillators which better corresponds to the structure of real crystals using the Condon relations is presented. This solution leads to the conclusion that, although it is possible to object to the Chandrasekhar solution method, the form of his final dispersion relations is correct. On the other hand, the dispersion relations following from the solution of more complicated coupled oscillator models are more convenient for the interpretation of the crystalline optical activity experimental data, which is demonstrated in examples of crystals of tellurium and benzil.
1999-07-19
Mrs. Lalitha Chandrasekhar (at podium), wife of the late Indian-American Nobel Laureate Subrahmanyan Chandrasekhar, addresses the media and other invited guests in the TRW Media Hospitality Tent at the NASA Press Site at KSC. Other participants in the program (seated facing the audience, left to right) are the winners of the contest to rename the telescope, Jatila van der Veen, academic coordinator and lecturer, Physics Dept., University of Santa Barbara, Calif., and Tyrel Johnson, high school student, Laclede, Idaho; Joanne Maguire, vice-president and general manager, TRW Space & Laser Programs Division; and Dr. Alan Bunner, Science Program Director, Structure and Evolution of the Universe, Office of Space Science, NASA Headquarters, Washington, D.C. The name "Chandra," a shortened version of Chandrasekhar, was the name the Nobel Laureate preferred among friends and colleagues. "Chandra" also means "Moon" or "luminous" in Sanskrit. The observatory is scheduled to be launched aboard Columbia on Space Shuttle mission STS-93
DOE Office of Scientific and Technical Information (OSTI.GOV)
Chandrasekhar, S.
In 1991 the Charles Greely Abbot Award of the American Solar Energy Society was awarded to Dr. Subrahmanyan Chandrasekhar, in recognition of his well-known work on the internal operation and life cycle of stars such as the sun, and for his development of the new radiation heat transfer and fluid flow analysis techniques he had found to be necessary to do this work. His acceptance address is presented here, which explains the relationship between Abbot's work on the solar constant and Dr. Chandrasekhar's research.
Factorization and reduction methods for optimal control of distributed parameter systems
NASA Technical Reports Server (NTRS)
Burns, J. A.; Powers, R. K.
1985-01-01
A Chandrasekhar-type factorization method is applied to the linear-quadratic optimal control problem for distributed parameter systems. An aeroelastic control problem is used as a model example to demonstrate that if computationally efficient algorithms, such as those of Chandrasekhar-type, are combined with the special structure often available to a particular problem, then an abstract approximation theory developed for distributed parameter control theory becomes a viable method of solution. A numerical scheme based on averaging approximations is applied to hereditary control problems. Numerical examples are given.
Hao, Qing; Wu, Song; Liu, Jian-min; Wang, Hua
2014-10-01
To observe the effects of electroacupuncture (EA) with branch-foundation acupoint combination on the indices regarding pituitary-target gland axis in aging rats with yang deficiency, so as to explore its regulating mechanism on aging rats with yang deficiency. Forty healthy Sprague-Dawley female rats were randomly divided into a normal control group, a model group, an EA group and an EA control group, 10 rats in each group. Except the normal control group, the rats in the rest 3 groups were all treated with subcutaneous injection of D-galactose for 40 d, followed by intramuscular injection of hydrocortisone for 7 d to establish aging model with yang deficiency. After the successful establishment of model, the EA group was treated with EA at "Guanyuan" (CV 4), "Housanli" (ST 36) and "Baihui "(GV 20) while the EA control group was treated with EA at "Zhongji" (CV 3) "Yinlingquan" (SP 9) and "Yintang" (GV 29); the rats in the normal control group and model group were immobilized and fixed during the same time period. The treatments were given 6 times per week totally for 4 weeks. With radiation immunity analysis method, the 8 biological indices of pituitary-target gland axis, including thyroid-stimulating hormone (TSH), triiodothyronine (T3), tetraiodothyronine-4 (T4), adrenocorticotropic hormone (ACTH), corticosterone (CORT), estradiol (E2), luteinizing hormone (LH) and follicle-stimulating hormone (FSH) were detected to observe the changes of their content. Compared with the normal control group, the serum level of TSH, T3, T4 and E2 were reduced in the model group (P<0.05, P< 0.01) while those of ACTH, CORT, FSH and LH were increased (P<0.05, P<0.01). Compared with the model group, the serum level of TSH, T3, T4 and E2 were increased in the EA group (P<0.05, P<0.01) while those of ACTH, CORT, FSH and LH were significantly reduced (P<0.05, P<0.01). Compared with the EA control group, the content of TSH was increased in the EA group without statistical significance
NASA Astrophysics Data System (ADS)
Baxter, J. Erik
2018-05-01
Here we study the global existence of "hairy" dyonic black hole and dyon solutions to four-dimensional, anti-de Sitter Einstein-Yang-Mills theories for a general simply connected and semisimple gauge group G, for the so-called topologically symmetric systems, concentrating here on the regular case. We generalise here cases in the literature which considered purely magnetic spherically symmetric solutions for a general gauge group and topological dyonic solutions for s u (N ) . We are able to establish the global existence of non-trivial solutions to all such systems, both near existing embedded solutions and as |Λ| → ∞. In particular, we can identify non-trivial solutions where the gauge field functions have no zeroes, which in the s u (N ) case proved important to stability. We believe that these are the most general analytically proven solutions in 4D anti-de Sitter Einstein-Yang-Mills systems to date.
Affine q-deformed symmetry and the classical Yang-Baxter σ-model
NASA Astrophysics Data System (ADS)
Delduc, F.; Kameyama, T.; Magro, M.; Vicedo, B.
2017-03-01
The Yang-Baxter σ-model is an integrable deformation of the principal chiral model on a Lie group G. The deformation breaks the G × G symmetry to U(1)rank( G) × G. It is known that there exist non-local conserved charges which, together with the unbroken U(1)rank( G) local charges, form a Poisson algebra [InlineMediaObject not available: see fulltext.], which is the semiclassical limit of the quantum group {U}_q(g) , with g the Lie algebra of G. For a general Lie group G with rank( G) > 1, we extend the previous result by constructing local and non-local conserved charges satisfying all the defining relations of the infinite-dimensional Poisson algebra [InlineMediaObject not available: see fulltext.], the classical analogue of the quantum loop algebra {U}_q(Lg) , where Lg is the loop algebra of g. Quite unexpectedly, these defining relations are proved without encountering any ambiguity related to the non-ultralocality of this integrable σ-model.
Higher spin gravitational couplings: Ghosts in the Yang-Mills detour complex
DOE Office of Scientific and Technical Information (OSTI.GOV)
Gover, A. R.; Hallowell, K.; Waldron, A.
2007-01-15
Gravitational interactions of higher spin fields are generically plagued by inconsistencies. There exists however, a simple framework that couples higher spins to a broad class of gravitational backgrounds (including Ricci flat and Einstein) consistently at the classical level. The model is the simplest example of a Yang-Mills detour complex and has broad mathematical applications, especially to conformal geometry. Even the simplest version of the theory, which couples gravitons, vectors and scalar fields in a flat background is rather rich, providing an explicit setting for detailed analysis of ghost excitations. Its asymptotic scattering states consist of a physical massless graviton, scalar,more » and massive vector along with a degenerate pair of zero norm photon excitations. Coherent states of the unstable sector do have positive norms, but their evolution is no longer unitary and amplitudes grow with time. The class of models proposed is extremely general and of considerable interest for ghost condensation and invariant theory.« less
Cao, Hong-Ying; Wu, Qing-He; Huang, Ping; He, Jin-Yang
2009-06-01
To observe the impacts of the formula of Suoquanwan (SQW) on the expression of AQP-2 mRNA and AVPR-V2 mRNA in the kidney of rat polyuria model of Yang-deficiency. The model rats were induced by adenine (250 mg/kg) for 4 weeks, then treated respectively with SQW or dDAVP. The expression of AQP-2 mRNA and AVPR-V2 mRNA in kidney of Yang-deficiency model by realtime fluorescence quantitative PCR method were investigated. In model rats, the expression of AQP-2 mRNA and AVPR-V2 mRNA in the kidney decreased, dDAVP and SQW high dose could increased the expression of AQP-2 mRNA and AVPR-V2 mRNA in the kidney. The others had no influence on the expression of AQP-2 mRNA and AVPR-V2 mRNA in the kidney. SQW can increase the expression of AQP-2 mRNA and AVPR-V2 mRNA in the kidney of rat polyuria model of Yang-deficiency.
Kaewpitoon, Soraya J; Rujirakul, Ratana; Joosiri, Apinya; Jantakate, Sirinun; Sangkudloa, Amnat; Kaewthani, Sarochinee; Chimplee, Kanokporn; Khemplila, Kritsakorn; Kaewpitoon, Natthawut
2016-01-01
Cholangiocarcinoma (CCA) is a serious problem in Thailand, particularly in the northeastern and northern regions. Database of population at risk are need required for monitoring, surveillance, home health care, and home visit. Therefore, this study aimed to develop a geographic information system (GIS) database and Google map of the population at risk of CCA in Mueang Yang district, Nakhon Ratchasima province, northeastern Thailand during June to October 2015. Populations at risk were screened using the Korat CCA verbal screening test (KCVST). Software included Microsoft Excel, ArcGIS, and Google Maps. The secondary data included the point of villages, sub-district boundaries, district boundaries, point of hospital in Mueang Yang district, used for created the spatial databese. The populations at risk for CCA and opisthorchiasis were used to create an arttribute database. Data were tranfered to WGS84 UTM ZONE 48. After the conversion, all of the data were imported into Google Earth using online web pages www.earthpoint.us. Some 222 from a 4,800 population at risk for CCA constituted a high risk group. Geo-visual display available at following www.google.com/maps/d/u/0/ edit?mid=zPxtcHv_iDLo.kvPpxl5mAs90 and hl=th. Geo-visual display 5 layers including: layer 1, village location and number of the population at risk for CCA; layer 2, sub-district health promotion hospital in Mueang Yang district and number of opisthorchiasis; layer 3, sub-district district and the number of population at risk for CCA; layer 4, district hospital and the number of population at risk for CCA and number of opisthorchiasis; and layer 5, district and the number of population at risk for CCA and number of opisthorchiasis. This GIS database and Google map production process is suitable for further monitoring, surveillance, and home health care for CCA sufferers.
Targeted Disruption of Mouse Yin Yang 1 Transcription Factor Results in Peri-Implantation Lethality
Donohoe, Mary E.; Zhang, Xiaolin; McGinnis, Lynda; Biggers, John; Li, En; Shi, Yang
1999-01-01
Yin Yang 1 (YY1) is a zinc finger-containing transcription factor and a target of viral oncoproteins. To determine the biological role of YY1 in mammalian development, we generated mice deficient for YY1 by gene targeting. Homozygosity for the mutated YY1 allele results in embryonic lethality in the mouse. YY1 mutants undergo implantation and induce uterine decidualization but rapidly degenerate around the time of implantation. A subset of YY1 heterozygote embryos are developmentally retarded and exhibit neurulation defects, suggesting that YY1 may have additional roles during later stages of mouse embryogenesis. Our studies demonstrate an essential function for YY1 in the development of the mouse embryo. PMID:10490658
Oh, Chaekun
2014-04-01
In this study, I aim to reveal how Lee Gyoojoons medicine has given birth to a current of learning, the supporting yang current of learning, and describe its historical significance. Before anything, I'd like to throw the question of whether if there were any currents within the traditional Korean medicine. There are no records of medical currents being widely discussed until now in medical history of Korea; however, the current of Lee Jema's sasang medicine is the most noticeable one. Among the contemporaries of Lee Jema, during the late Chosun, there was also another famed medical practitioner called Lee Gyoojoon. Lee Gyoojoon mainly practiced his medicine within Pohang, Gyeongsangbuk-do area, his apprentices have formed a group and have succeeded his medical practice. Based on the analyses of Lee Gyoojoon's apprentices and the Somun Oriental Medical Society, which is known as a successor group to Lee Gyoojoon's medicine today, they are fully satisfying the five requirements to establish a medical current: first, they held Lee Gyoojoon as the first and foremost, representative practitioner of their current; second, they advocate the supporting yang theory suggested by Lee Gyoojoon, which is originated from his theory of Mind; third, books such as the Major Essentials of Huangdi's Internal Classic Plain Questions, and the Double Grinded Medical Mirror, were being used as the main textbooks to educate their students or to practice medicine. Fourth, Lee Gyoojoon's medical ideas were being transcended quite clearly within his group of apprentices, including Seo Byungoh, Lee Wonse, and the Somun Oriental Medical Society. Fifth, Lee Gyoojoon's apprentices were first produced through the Sukgok School, however, nowadays they are being produced through medical groups formed by Lee Wonse, the Somun Oriental Medical Society, regarding the propagation of medical theories, compilation of textbooks, publication of academic journals, etc. Then, what do the existence of the
Design and Implementation of e-Health System Based on Semantic Sensor Network Using IETF YANG.
Jin, Wenquan; Kim, Do Hyeun
2018-02-20
Recently, healthcare services can be delivered effectively to patients anytime and anywhere using e-Health systems. e-Health systems are developed through Information and Communication Technologies (ICT) that involve sensors, mobiles, and web-based applications for the delivery of healthcare services and information. Remote healthcare is an important purpose of the e-Health system. Usually, the eHealth system includes heterogeneous sensors from diverse manufacturers producing data in different formats. Device interoperability and data normalization is a challenging task that needs research attention. Several solutions are proposed in the literature based on manual interpretation through explicit programming. However, programmatically implementing the interpretation of the data sender and data receiver in the e-Health system for the data transmission is counterproductive as modification will be required for each new device added into the system. In this paper, an e-Health system with the Semantic Sensor Network (SSN) is proposed to address the device interoperability issue. In the proposed system, we have used IETF YANG for modeling the semantic e-Health data to represent the information of e-Health sensors. This modeling scheme helps in provisioning semantic interoperability between devices and expressing the sensing data in a user-friendly manner. For this purpose, we have developed an ontology for e-Health data that supports different styles of data formats. The ontology is defined in YANG for provisioning semantic interpretation of sensing data in the system by constructing meta-models of e-Health sensors. The proposed approach assists in the auto-configuration of eHealth sensors and querying the sensor network with semantic interoperability support for the e-Health system.
Design and Implementation of e-Health System Based on Semantic Sensor Network Using IETF YANG
Kim, Do Hyeun
2018-01-01
Recently, healthcare services can be delivered effectively to patients anytime and anywhere using e-Health systems. e-Health systems are developed through Information and Communication Technologies (ICT) that involve sensors, mobiles, and web-based applications for the delivery of healthcare services and information. Remote healthcare is an important purpose of the e-Health system. Usually, the eHealth system includes heterogeneous sensors from diverse manufacturers producing data in different formats. Device interoperability and data normalization is a challenging task that needs research attention. Several solutions are proposed in the literature based on manual interpretation through explicit programming. However, programmatically implementing the interpretation of the data sender and data receiver in the e-Health system for the data transmission is counterproductive as modification will be required for each new device added into the system. In this paper, an e-Health system with the Semantic Sensor Network (SSN) is proposed to address the device interoperability issue. In the proposed system, we have used IETF YANG for modeling the semantic e-Health data to represent the information of e-Health sensors. This modeling scheme helps in provisioning semantic interoperability between devices and expressing the sensing data in a user-friendly manner. For this purpose, we have developed an ontology for e-Health data that supports different styles of data formats. The ontology is defined in YANG for provisioning semantic interpretation of sensing data in the system by constructing meta-models of e-Health sensors. The proposed approach assists in the auto-configuration of eHealth sensors and querying the sensor network with semantic interoperability support for the e-Health system. PMID:29461493
A note on local BRST cohomology of Yang-Mills type theories with free Abelian factors
NASA Astrophysics Data System (ADS)
Barnich, Glenn; Boulanger, Nicolas
2018-05-01
We extend previous work on antifield dependent local Becchi-Rouet-Stora-Tyutin (BRST) cohomology for matter coupled gauge theories of Yang-Mills type to the case of gauge groups that involve free Abelian factors. More precisely, we first investigate in a model independent way how the dynamics enters the computation of the cohomology for a general class of Lagrangians in general spacetime dimensions. We then discuss explicit solutions in the case of specific models. Our analysis has implications for the structure of characteristic cohomology and for consistent deformations of the classical models, as well as for divergences/counterterms and for gauge anomalies that may appear during perturbative quantization.
NASA Astrophysics Data System (ADS)
Dai, Jia-Liang; Fan, En-Gui
2018-05-01
We obtain the instanton correction recursion relations for the low energy effective prepotential in pure {\\mathscr{N}}=2 SU(n) supersymmetric Yang-Mills gauge theory from Whitham hierarchy and Seiberg-Witten/Whitham equations. These formulae provide us a powerful tool to calculate arbitrary order instanton corrections coefficients from the perturbative contributions of the effective prepotential in Seiberg-Witten gauge theory. We apply this idea to evaluate one- and twoorder instanton corrections coefficients explicitly in SU(n) case in detail through the dynamical scale parameter expressed in terms of Riemann’s theta-function. Supported by the National Natural Science Foundation of China under Grant No. 11271079
Matrix models for 5d super Yang-Mills
NASA Astrophysics Data System (ADS)
Minahan, Joseph A.
2017-11-01
In this contribution to the issue on localization in gauge theories we investigate the matrix models derived from localizing N=1 super Yang-Mills on S 5. We consider the large-N limit and attempt to solve the matrix model by a saddle-point approximation. In general it is not possible to find an analytic solution, but at the weak and the strong limits of the ’t Hooft coupling there are dramatic simplifications that allows us to extract most of the interesting information. At weak coupling we show that the matrix model is close to the Gaussian matrix model and that the free-energy scales as N 2. At strong coupling we show that if the theory contains one adjoint hypermultiplet then the free-energy scales as N 3. We also find the expectation value of a supersymmetric Wilson loop that wraps the equator. We demonstrate how to extract the effective couplings and reproduce results of Seiberg. Finally, we compare to results for the six-dimensional (2,0) theory derived using the AdS/CFT correspondence. We show that by choosing the hypermultiplet mass such that the supersymmetry is enhanced to N=2 , the Wilson loop result matches the analogous calculation using AdS/CFT. The free-energies differ by a rational fraction. This is a contribution to the review issue ‘Localization techniques in quantum field theories’ (ed Pestun and Zabzine) which contains 17 chapters available at [1].
Yin Yang 1 Promotes Hepatic Gluconeogenesis Through Upregulation of Glucocorticoid Receptor
Lu, Yan; Xiong, Xuelian; Wang, Xiaolin; Zhang, Zhijian; Li, Jin; Shi, Guojun; Yang, Jian; Zhang, Huijie; Ning, Guang; Li, Xiaoying
2013-01-01
Gluconeogenesis is critical in maintaining blood glucose levels in a normal range during fasting. In this study, we investigated the role of Yin Yang 1 (YY1), a key transcription factor involved in cell proliferation and differentiation, in the regulation of hepatic gluconeogenesis. Our data showed that hepatic YY1 expression levels were induced in mice during fasting conditions and in a state of insulin resistance. Overexpression of YY1 in livers augmented gluconeogenesis, raising fasting blood glucose levels in C57BL/6 mice, whereas liver-specific ablation of YY1 using adenoviral shRNA ameliorated hyperglycemia in wild-type and diabetic db/db mice. At the molecular level, we further demonstrated that the major mechanism of YY1 in the regulation of hepatic glucose production is to modulate the expression of glucocorticoid receptor. Therefore, our study uncovered for the first time that YY1 participates in the regulation of hepatic gluconeogenesis, which implies that YY1 might serve as a potential therapeutic target for hyperglycemia in diabetes. PMID:23193188
Nonperturbative study of dynamical SUSY breaking in N =(2 ,2 ) Yang-Mills theory
NASA Astrophysics Data System (ADS)
Catterall, Simon; Jha, Raghav G.; Joseph, Anosh
2018-03-01
We examine the possibility of dynamical supersymmetry breaking in two-dimensional N =(2 ,2 ) supersymmetric Yang-Mills theory. The theory is discretized on a Euclidean spacetime lattice using a supersymmetric lattice action. We compute the vacuum energy of the theory at finite temperature and take the zero-temperature limit. Supersymmetry will be spontaneously broken in this theory if the measured ground-state energy is nonzero. By performing simulations on a range of lattices up to 96 ×96 we are able to perform a careful extrapolation to the continuum limit for a wide range of temperatures. Subsequent extrapolations to the zero-temperature limit yield an upper bound on the ground-state energy density. We find the energy density to be statistically consistent with zero in agreement with the absence of dynamical supersymmetry breaking in this theory.
An object oriented code for simulating supersymmetric Yang-Mills theories
NASA Astrophysics Data System (ADS)
Catterall, Simon; Joseph, Anosh
2012-06-01
We present SUSY_LATTICE - a C++ program that can be used to simulate certain classes of supersymmetric Yang-Mills (SYM) theories, including the well known N=4 SYM in four dimensions, on a flat Euclidean space-time lattice. Discretization of SYM theories is an old problem in lattice field theory. It has resisted solution until recently when new ideas drawn from orbifold constructions and topological field theories have been brought to bear on the question. The result has been the creation of a new class of lattice gauge theories in which the lattice action is invariant under one or more supersymmetries. The resultant theories are local, free of doublers and also possess exact gauge-invariance. In principle they form the basis for a truly non-perturbative definition of the continuum SYM theories. In the continuum limit they reproduce versions of the SYM theories formulated in terms of twisted fields, which on a flat space-time is just a change of the field variables. In this paper, we briefly review these ideas and then go on to provide the details of the C++ code. We sketch the design of the code, with particular emphasis being placed on SYM theories with N=(2,2) in two dimensions and N=4 in three and four dimensions, making one-to-one comparisons between the essential components of the SYM theories and their corresponding counterparts appearing in the simulation code. The code may be used to compute several quantities associated with the SYM theories such as the Polyakov loop, mean energy, and the width of the scalar eigenvalue distributions. Program summaryProgram title: SUSY_LATTICE Catalogue identifier: AELS_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AELS_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC license, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 9315 No. of bytes in distributed program
Quantum probe of Hořava-Lifshitz gravity
NASA Astrophysics Data System (ADS)
Gurtug, O.; Mangut, M.
2018-04-01
Particle probe analysis of the Kehagias-Sfetsos black hole spacetime of Hořava-Lifshitz gravity is extended to wave probe analysis within the framework of quantum mechanics. The time-like naked singularity that develops when ωM2 < 1/2 is probed with quantum fields obeying Klein-Gordon and Chandrasekhar-Dirac equations. The quantum field probe of the naked singularity has revealed that both the spatial part of the wave and the Hamiltonian operators of Klein-Gordon and Chandrasekhar-Dirac equations are essentially self-adjoint, and thus, the naked singularity in the Kehagias-Sfetsos spacetime becomes quantum mechanically non-singular.
The Analytic Structure of Scattering Amplitudes in N = 4 Super-Yang-Mills Theory
NASA Astrophysics Data System (ADS)
Litsey, Sean Christopher
We begin the dissertation in Chapter 1 with a discussion of tree-level amplitudes in Yang-. Mills theories. The DDM and BCJ decompositions of the amplitudes are described and. related to one another by the introduction of a transformation matrix. This is related to the. Kleiss-Kuijf and BCJ amplitude identities, and we conjecture a connection to the existence. of a BCJ representation via a condition on the generalized inverse of that matrix. Under. two widely-believed assumptions, this relationship is proved. Switching gears somewhat, we introduce the RSVW formulation of the amplitude, and the extension of BCJ-like features to residues of the RSVW integrand is proposed. Using the previously proven connection of BCJ representations to the generalized inverse condition, this extension is validated, including a version of gravitational double copy. The remainder of the dissertation involves an analysis of the analytic properties of loop. amplitudes in N = 4 super-Yang-Mills theory. Chapter 2 contains a review of the planar case, including an exposition of dual variables and momentum twistors, dual conformal symmetry, and their implications for the amplitude. After defining the integrand and on-shell diagrams, we explain the crucial properties that the amplitude has no poles at infinite momentum and that its leading singularities are dual-conformally-invariant cross ratios, and can therefore be normalized to unity. We define the concept of a dlog form, and show that it is a feature of the planar integrand as well. This leads to the definition of a pure integrand basis. The proceeding setup is connected to the amplituhedron formulation, and we put forward the hypothesis that the amplitude is determined by zero conditions. Chapter 3 contains the primary computations of the dissertation. This chapter treats. amplitudes in fully nonplanar N = 4 super-Yang-Mills, analyzing the conjecture that they. follow the pattern of having no poles at infinity, can be written in dlog
Castro-Chavez, Fernando
2014-01-01
Objective The objective of this article is to demonstrate that the genetic code can be studied and represented in a 3-D Sphered Cube for bioinformatics and for education by using the graphical help of the ancient “Book of Changes” or I Ching for the comparison, pair by pair, of the three basic characteristics of nucleotides: H-bonds, molecular structure, and their tautomerism. Methods The source of natural biodiversity is the high plasticity of the genetic code, analyzable with a reverse engineering of its 2-D and 3-D representations (here illustrated), but also through the classical 64-hexagrams of the ancient I Ching, as if they were the 64-codons or words of the genetic code. Results In this article, the four elements of the Yin/Yang were found by correlating the 3×2=6 sets of Cartesian comparisons of the mentioned properties of nucleic acids, to the directionality of their resulting blocks of codons grouped according to their resulting amino acids and/or functions, integrating a 384-codon Sphered Cube whose function is illustrated by comparing six brain peptides and a promoter of osteoblasts from Humans versus Neanderthal, as well as to Negadi’s work on the importance of the number 384 within the genetic code. Conclusions Starting with the codon/anticodon correlation of Nirenberg, published in full here for the first time, and by studying the genetic code and its 3-D display, the buffers of reiteration within codons codifying for the same amino acid, displayed the two long (binary number one) and older Yin/Yang arrows that travel in opposite directions, mimicking the parental DNA strands, while annealing to the two younger and broken (binary number zero) Yin/Yang arrows, mimicking the new DNA strands; the graphic analysis of the of the genetic code and its plasticity was helpful to compare compatible sequences (human compatible to human versus neanderthal compatible to neanderthal), while further exploring the wondrous biodiversity of nature for
A Computer Analysis Study of the Word Style in Love-songs of Tshang yang Gya tsho
NASA Astrophysics Data System (ADS)
Yonghong, Li; SunTing; Lei, Guo; Hongzhi, Yu
Based on the statistical methods of corpus and the 124 love-songs of Tshang yang Gya tsho as the studying object, this paper have set up the principles of vocabulary segmentation and built the love-songs corpus of Tibetan and Tibetan-Chinese grammar separation lexicon corpus. Then it did quantitative research on the achievement of "love-songs" in the language arts from three aspects: the length of the vocabularie's, the frequency rate of the vocabularies, and the distribution of the term's number in the verses and the songs. In addition it also introduced a new kind of researching idea and method for the study of Tibetan literature.
Trajectory phase transitions and dynamical Lee-Yang zeros of the Glauber-Ising chain.
Hickey, James M; Flindt, Christian; Garrahan, Juan P
2013-07-01
We examine the generating function of the time-integrated energy for the one-dimensional Glauber-Ising model. At long times, the generating function takes on a large-deviation form and the associated cumulant generating function has singularities corresponding to continuous trajectory (or "space-time") phase transitions between paramagnetic trajectories and ferromagnetically or antiferromagnetically ordered trajectories. In the thermodynamic limit, the singularities make up a whole curve of critical points in the complex plane of the counting field. We evaluate analytically the generating function by mapping the generator of the biased dynamics to a non-Hermitian Hamiltonian of an associated quantum spin chain. We relate the trajectory phase transitions to the high-order cumulants of the time-integrated energy which we use to extract the dynamical Lee-Yang zeros of the generating function. This approach offers the possibility to detect continuous trajectory phase transitions from the finite-time behavior of measurable quantities.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Yamaguchi, Hiroya; Badenes, Carles; Foster, Adam R.
Despite decades of intense efforts, many fundamental aspects of Type Ia supernovae (SNe Ia) remain elusive. One of the major open questions is whether the mass of an exploding white dwarf (WD) is close to the Chandrasekhar limit. Here, we report the detection of strong K-shell emission from stable Fe-peak elements in the Suzaku X-ray spectrum of the Type Ia supernova remnant (SNR) 3C 397. The high Ni/Fe and Mn/Fe mass ratios (0.11–0.24 and 0.018–0.033, respectively) in the hot plasma component that dominates the K-shell emission lines indicate a degree of neutronization in the supernova ejecta that can only bemore » achieved by electron capture in the dense cores of exploding WDs with a near-Chandrasekhar mass. This suggests a single-degenerate origin for 3C 397, since Chandrasekhar mass progenitors are expected naturally if the WD accretes mass slowly from a companion. Altogether with other results supporting the double-degenerate scenario, our work adds to the mounting evidence that both progenitor channels make a significant contribution to the SN Ia rate in star-forming galaxies.« less
A noncompact Weyl-Einstein-Yang-Mills model: A semiclassical quantum gravity
NASA Astrophysics Data System (ADS)
Dengiz, Suat
2017-08-01
We construct and study perturbative unitarity (i.e., ghost and tachyon analysis) of a 3 + 1-dimensional noncompact Weyl-Einstein-Yang-Mills model. The model describes a local noncompact Weyl's scale plus SU(N) phase invariant Higgs-like field,conformally coupled to a generic Weyl-invariant dynamical background. Here, the Higgs-like sector generates the Weyl's conformal invariance of system. The action does not admit any dimensionful parameter and genuine presence of de Sitter vacuum spontaneously breaks the noncompact gauge symmetry in an analogous manner to the Standard Model Higgs mechanism. As to flat spacetime, the dimensionful parameter is generated within the dimensional transmutation in quantum field theories, and thus the symmetry is radiatively broken through the one-loop Effective Coleman-Weinberg potential. We show that the mere expectation of reducing to Einstein's gravity in the broken phases forbids anti-de Sitter space to be its stable vacua. The model is unitary in de Sitter and flat vacua around which a massless graviton, N2 - 1 massless scalar bosons, N massless Dirac fermions, N2 - 1 Proca-type massive Abelian and non-Abelian vector bosons are generically propagated.
Black p-branes versus black holes in non-asymptotically flat Einstein-Yang-Mills theory
NASA Astrophysics Data System (ADS)
Habib Mazharimousavi, S.; Halilsoy, M.
2016-09-01
We present a class of non-asymptotically flat (NAF) charged black p-branes (BpB) with p-compact dimensions in higher-dimensional Einstein-Yang-Mills theory. Asymptotically the NAF structure manifests itself as an anti-de sitter spacetime. We determine the total mass/energy enclosed in a thin shell located outside the event horizon. By comparing the entropies of BpB with those of black holes in the same dimensions we derive transition criteria between the two types of black objects. Given certain conditions satisfied, our analysis shows that BpB can be considered excited states of black holes. An event horizon r+ versus charge square Q2 plot for the BpB reveals such a transition where r+ is related to the horizon radius rh of the black hole (BH) both with the common charge Q.
Jin, Yan; Tan, Yingling; Hu, Xiaozhen; Zhu, Bin; Zheng, Qinghui; Zhang, Zijiao; Zhu, Guoying; Yu, Qian; Jin, Zhong; Zhu, Jia
2017-05-10
Alloy anodes possessed of high theoretical capacity show great potential for next-generation advanced lithium-ion battery. Even though huge volume change during lithium insertion and extraction leads to severe problems, such as pulverization and an unstable solid-electrolyte interphase (SEI), various nanostructures including nanoparticles, nanowires, and porous networks can address related challenges to improve electrochemical performance. However, the complex and expensive fabrication process hinders the widespread application of nanostructured alloy anodes, which generate an urgent demand of low-cost and scalable processes to fabricate building blocks with fine controls of size, morphology, and porosity. Here, we demonstrate a scalable and low-cost process to produce a porous yin-yang hybrid composite anode with graphene coating through high energy ball-milling and selective chemical etching. With void space to buffer the expansion, the produced functional electrodes demonstrate stable cycling performance of 910 mAh g -1 over 600 cycles at a rate of 0.5C for Si-graphene "yin" particles and 750 mAh g -1 over 300 cycles at 0.2C for Sn-graphene "yang" particles. Therefore, we open up a new approach to fabricate alloy anode materials at low-cost, low-energy consumption, and large scale. This type of porous silicon or tin composite with graphene coating can also potentially play a significant role in thermoelectrics and optoelectronics applications.
Merging white dwarfs and thermonuclear supernovae.
van Kerkwijk, M H
2013-06-13
Thermonuclear supernovae result when interaction with a companion reignites nuclear fusion in a carbon-oxygen white dwarf, causing a thermonuclear runaway, a catastrophic gain in pressure and the disintegration of the whole white dwarf. It is usually thought that fusion is reignited in near-pycnonuclear conditions when the white dwarf approaches the Chandrasekhar mass. I briefly describe two long-standing problems faced by this scenario, and the suggestion that these supernovae instead result from mergers of carbon-oxygen white dwarfs, including those that produce sub-Chandrasekhar-mass remnants. I then turn to possible observational tests, in particular, those that test the absence or presence of electron captures during the burning.
Self-dual phase space for (3 +1 )-dimensional lattice Yang-Mills theory
NASA Astrophysics Data System (ADS)
Riello, Aldo
2018-01-01
I propose a self-dual deformation of the classical phase space of lattice Yang-Mills theory, in which both the electric and magnetic fluxes take value in the compact gauge Lie group. A local construction of the deformed phase space requires the machinery of "quasi-Hamiltonian spaces" by Alekseev et al., which is reviewed here. The results is a full-fledged finite-dimensional and gauge-invariant phase space, the self-duality properties of which are largely enhanced in (3 +1 ) spacetime dimensions. This enhancement is due to a correspondence with the moduli space of an auxiliary noncommutative flat connection living on a Riemann surface defined from the lattice itself, which in turn equips the duality between electric and magnetic fluxes with a neat geometrical interpretation in terms of a Heegaard splitting of the space manifold. Finally, I discuss the consequences of the proposed deformation on the quantization of the phase space, its quantum gravitational interpretation, as well as its relevance for the construction of (3 +1 )-dimensional topological field theories with defects.
Testing holography using lattice super-Yang-Mills theory on a 2-torus
NASA Astrophysics Data System (ADS)
Catterall, Simon; Jha, Raghav G.; Schaich, David; Wiseman, Toby
2018-04-01
We consider maximally supersymmetric SU (N ) Yang-Mills theory in Euclidean signature compactified on a flat two-dimensional torus with antiperiodic ("thermal") fermion boundary conditions imposed on one cycle. At large N , holography predicts that this theory describes certain black hole solutions in type IIA and IIB supergravity, and we use lattice gauge theory to test this. Unlike the one-dimensional quantum mechanics case where there is only the dimensionless temperature to vary, here we emphasize there are two more parameters which determine the shape of the flat torus. While a rectangular Euclidean torus yields a thermal interpretation, allowing for skewed tori modifies the holographic dual black hole predictions and results in another direction to test holography. Our lattice calculations are based on a supersymmetric formulation naturally adapted to a particular skewing. Using this we perform simulations up to N =16 with several lattice spacings for both skewed and rectangular tori. We observe the two expected black hole phases with their predicted behavior, with a transition between them that is consistent with the gravity prediction based on the Gregory-Laflamme transition.
Dark energy as a fixed point of the Einstein Yang-Mills Higgs equations
DOE Office of Scientific and Technical Information (OSTI.GOV)
Rinaldi, Massimiliano, E-mail: massimiliano.rinaldi@unitn.it
We study the Einstein Yang-Mills Higgs equations in the SO(3) representation on a isotropic and homogeneous flat Universe, in the presence of radiation and matter fluids. We map the equations of motion into an autonomous dynamical system of first-order differential equations and we find the equilibrium points. We show that there is only one stable fixed point that corresponds to an accelerated expanding Universe in the future. In the past, instead, there is an unstable fixed point that implies a stiff-matter domination. In between, we find three other unstable fixed points, corresponding, in chronological order, to radiation domination, to mattermore » domination, and, finally, to a transition from decelerated expansion to accelerated expansion. We solve the system numerically and we confirm that there are smooth trajectories that correctly describe the evolution of the Universe, from a remote past dominated by radiation to a remote future dominated by dark energy, passing through a matter-dominated phase.« less
Dark energy as a fixed point of the Einstein Yang-Mills Higgs equations
NASA Astrophysics Data System (ADS)
Rinaldi, Massimiliano
2015-10-01
We study the Einstein Yang-Mills Higgs equations in the SO(3) representation on a isotropic and homogeneous flat Universe, in the presence of radiation and matter fluids. We map the equations of motion into an autonomous dynamical system of first-order differential equations and we find the equilibrium points. We show that there is only one stable fixed point that corresponds to an accelerated expanding Universe in the future. In the past, instead, there is an unstable fixed point that implies a stiff-matter domination. In between, we find three other unstable fixed points, corresponding, in chronological order, to radiation domination, to matter domination, and, finally, to a transition from decelerated expansion to accelerated expansion. We solve the system numerically and we confirm that there are smooth trajectories that correctly describe the evolution of the Universe, from a remote past dominated by radiation to a remote future dominated by dark energy, passing through a matter-dominated phase.
S-Duality, Deconstruction and Confinement for a Marginal Deformation of N=4 SUSY Yang-Mills
NASA Astrophysics Data System (ADS)
Dorey, Nick
2004-08-01
We study an exactly marginal deformation of Script N = 4 SUSY Yang-Mills with gauge group U(N) using field theory and string theory methods. The classical theory has a Higgs branch for rational values of the deformation parameter. We argue that the quantum theory also has an S-dual confining branch which cannot be seen classically. The low-energy effective theory on these branches is a six-dimensional non-commutative gauge theory with sixteen supercharges. Confinement of magnetic and electric charges, on the Higgs and confining branches respectively, occurs due to the formation of BPS-saturated strings in the low energy theory. The results also suggest a new way of deconstructing Little String Theory as a large-N limit of a confining gauge theory in four dimensions.
The "enduring mission" of Zing-Yang Kuo to eliminate the nature-nurture dichotomy in psychology.
Honeycutt, Hunter
2011-05-01
This paper reviews the arguments against the instinct concept and the nature-nurture dichotomy put forward by Zing-Yang Kuo (1898-1970) during the 1920s. Kuo insisted that nativism represented a kind of finished psychology, and that the labels of nature and nurture reflected and promoted one's ignorance of the development of a trait. Also discussed are his lesser known lines of research on the origins of the so-called rat-killing instinct in cats and his analysis on the determinants of animal fighting. His research illustrated the shortcomings of a nature-nurture framework and highlighted the necessity of his developmentally grounded alternative to studying behavior. Reasons for why Kuo's work has been marginalized in modern histories of psychology are also discussed. Copyright © 2011 Wiley Periodicals, Inc.
Finite field equation of Yang--Mills theory
DOE Office of Scientific and Technical Information (OSTI.GOV)
Brandt, R.A.; Wing-Chiu, N.; Yeung, W.
1980-03-01
We consider the finite local field equation -)(1+1/..cap alpha.. (1+f/sub 4/))g/sup munu/D'Alembertian-partial/sup ..mu../partial/sup ..nu../)A/sup nua/ =-(1+f/sub 3/) g/sup 2/N(A/sup c/..nu..A/sup a/..mu..A/sub ..nu..//sup c/) +xxx+(1-s)/sup 2/M/sup 2/A/sup a/..mu.., introduced by Lowenstein to rigorously describe SU(2) Yang--Mills theory, which is written in terms of normal products. We also consider the operator product expansion A/sup c/..nu..(x+xi) A/sup a/..mu..(x) A/sup b/lambda(x-xi) approx...sigma..M/sup c/ab..nu mu..lambda/sub c/'a'b'..nu..'..mu..'lambda' (xi) N(A/sup nuprimec/'A/sup muprimea/'A/sup lambdaprimeb/')(x), and using asymptotic freedom, we compute the leading behavior of the Wilson coefficients M/sup ...//sub .../(xi) with the help of a computer, and express the normal products in the field equation in terms ofmore » products of the c-number Wilson coefficients and of operator products like A/sup c/..nu..(x+xi) A/sup a/..mu..(x) A/sup b/lambda(x-xi) at separated points. Our result is -)(1+(1/..cap alpha..)(1+f/sub 4/))g/sup munu/D'Alembertian-partial/sup ..mu../partial/sup ..nu../)A/sup nua/ =-(1+f/sub 3/) g/sup 2/lim/sub xiarrow-right0/) (lnxi)/sup -0.28/2b/(A/sup c/..nu.. (x+xi) A/sup a/..mu..(x) A/sub ..nu..//sup c/(x-xi) +epsilon/sup a/bcA/sup muc/(x+xi) partial/sup ..nu../A/sup b//sub ..nu../(x)+xxx) +xxx)+(1-s)/sup 2/M/sup 2/A/sup a/..mu.., where ..beta.. (g) =-bg/sup 3/, and so (lnxi)/sup -0.28/2b/ is the leading behavior of the c-number coefficient multiplying the operator products in the field equation.« less
Infrared conductivity of cuprates using Yang-Rice-Zhang ansatz: Review of our recent investigations
DOE Office of Scientific and Technical Information (OSTI.GOV)
Singh, Navinder; Sharma, Raman
2015-05-15
A review of our recent investigations related to the ac transport properties in the psedogapped state of cuprate high temperature superconductors is presented. For our theoretical calculations we use a phenomenological Green’s function proposed by Yang, Rice and Zhang (YRZ). This is based upon the renormalized mean-field theory of the Hubbard model and takes into account the strong electron-electron interaction present in Cuprates. The pseudogap is also taken into account through a proposed self energy. We have tested the form of the Green’s function by computing ac conductivity of cuprates and then compared with experimental results. We found agreement betweenmore » theory and experiment in reproducing the doping evolution of ac conductivity but there is a problem with absolute magnitudes and their frequency dependence. This shows a partial success of the YRZ ansatz. The ways to rectify it are suggested and worked out.« less
1999-07-19
KENNEDY SPACE CENTER, FLA. -- Mrs. Lalitha Chandrasekhar (right), wife of the late Indian-American Nobel Laureate Subrahmanyan Chandrasekhar, addresses the media and other invited guests in the TRW Media Hospitality Tent at the NASA Press Site at KSC as Dr. Alan Bunner, Science Program Director, Structure and Evolution of the Universe, Office of Space Science, NASA Headquarters, Washington, D.C., looks on. The name "Chandra," a shortened version of her husband's name which he preferred among friends and colleagues, was chosen in a contest to rename the Advanced X-ray Astrophysics Facility. "Chandra" also means "Moon" or "luminous" in Sanskrit. The observatory is scheduled to be launched aboard Columbia on Space Shuttle mission STS-93
Tachyonic instabilities in 2 + 1 dimensional Yang-Mills theory and its connection to number theory
NASA Astrophysics Data System (ADS)
Chamizo, Fernando; González-Arroyo, Antonio
2017-06-01
We consider the 2 + 1 dimensional Yang-Mills theory with gauge group {{SU}}(N) on a flat 2-torus under twisted boundary conditions. We study the possibility of phase transitions (tachyonic instabilities) when N and the volume vary and certain chromomagnetic flux associated to the topology of the bundle can be adjusted. Under natural assumptions about how to match the perturbative regime and the expected confinement, we prove that the absence of tachyonic instabilities is related to some problems in number theory, namely the Diophantine approximation of irreducible fractions by other fractions of smaller denominator.
The Yin and Yang of Formative Research in Designing Serious (Exer-)games.
DeSmet, Ann; Palmeira, António; Beltran, Alicia; Brand, Leah; Davies, Vanessa Fernandes; Thompson, Debbe
2015-02-01
Despite its relevance, formative research on games may be an undervalued part of the game development process. At the 2014 International Society of Behavioral Nutrition and Physical Activity exergaming preconference satellite meeting, a roundtable discussion was held to assemble experiences and suggestions on enhancing the use of formative research in the development of active videogames (i.e., exergames). This article presents a summary of the concepts discussed. The discussants concluded that, although formative research may slightly expand the project timeline, the potential benefits include a game more in line with preferences of the intended users, with better operationalized theoretical constructs and broader stakeholder support, facilitating implementation and sustainability. It also improves the efficiency of other research parts because of a lower dropout rate of participants. Formative, qualitative research is thus a necessary complement to quantitative measurements of intervention outcomes, in a sort of Yin and Yang dynamic. An adapted version of formative research that casts a wider net may, however, be needed, involving both behavioral scientists and game developers, expanding the topics beyond the game's looks and soliciting the opinions of a larger group of stakeholders, such as implementers, gatekeepers, and funders.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Singh, Navinder; Sharma, Raman
In the underdoped regime of the cuprate phase diagram, the modified version of the Resonance Valence Bond (RVB) model by Yang, Rice and Zhang (YRZ) captures the strong electronic correlation effects very well as corroborated by the ARPES and many other experiments. However, under a non-equilibrium transport setting, YRZ says nothing about the scattering mechanisms of the charge carriers. In the present investigation we include, in a very simplified way, the scattering of charge carriers due to antiferromagnetic type spin waves (ASW). The effect of ASW excitations on conductivity has been studied by changing combined life times of the includedmore » process. It has been found that there is a qualitative change in the conductivity in the right direction. The theoretical conductivity reproduces qualitatively the experimental one.« less
Exact equivalence of the D=4 gauged Wess-Zumino-Witten term and the D=5 Yang-Mills Chern-Simons term
DOE Office of Scientific and Technical Information (OSTI.GOV)
Hill, Christopher T.
We derive the full Wess-Zumino-Witten term of a gauged chiral Lagrangian in D=4 by starting from a pure Yang-Mills theory of gauged quark flavor in a flat, compactified D=5. The theory is compactified such that there exists a B{sub 5} zero mode, and supplemented with quarks that are 'chirally delocalized' with q{sub L} (q{sub R}) on the left (right) boundary (brane). The theory then necessarily contains a Chern-Simons term (anomaly flux) to cancel the fermionic anomalies on the boundaries. The constituent quark mass represents chiral symmetry breaking and is a bilocal operator in D=5 of the form: q{sub L}Wq{sub R}+h.c,more » where W is the Wilson line spanning the bulk, 0{<=}x{sup 5}{<=}R, and is interpreted as a chiral meson field, W=exp(2i{pi}-tilde/f{sub {pi}}), where f{sub {pi}}{approx}1/R. The quarks are integrated out, yielding a Dirac determinant which takes the form of a 'boundary term' (anomaly flux return), and is equivalent to Bardeen's counterterm that connects consistent and covariant anomalies. The Wess-Zumino-Witten term then emerges straightforwardly, from the Yang-Mills Chern-Simons term, plus boundary term. The method is systematic and allows generalization of the Wess-Zumino-Witten term to theories of extra dimensions, and to express it in alternative and more compact forms. We give a novel form appropriate to the case of (unintegrated) massless fermions.« less
Left-right and Yin-Yang balance of biophoton emission from hands.
Yang, Joon-mo; Choi, Chunho; Hyun-hee; Woo, Won-myung; Yi, Seung-ho; Soh, Kwang-sup; Yang, Jong Soo; Choi, C
2004-01-01
Yearlong measurements of biophotons from palm and back of hand of three healthy people were performed. The detection of biophoton was done with two photomultiplier tubes whose spectral range was from 300 nm to 650 nm. The measurement was done on a circular area of diameter 46 mm whose centers were at the acupuncture point Laogong (PC8) of a palm and the mid-point of a back, respectively. The emission rates from the dorsa showed strong seasonal dependence which is consistent with the active nature of Yang meridians, while the palm sides show less seasonal dependence as they belong to the passive Yin meridians. This could be quantified simply by the standard deviations from the yearly average: They were 47.6 counts per second (cps), 66.1 cps and 66.0 cps from the dorsa, and 23.8 cps, 29.7 cps and 30.4 cps from the palms of subject 1, 2 and 3, respectively. Biophoton emission revealed qualitative individual tendencies: The subjects 1 and 2 emitted more strongly from the left dorsa, while the subject 3 from the right dorsum. The left-right balance of biophoton emission was well kept for normal people, which is in contrast with the severe imbalance for some stroke patients. Thus biophoton measurement has a diagnostic potential that encourages more studies.
Viscous Rayleigh-Taylor instability in spherical geometry
NASA Astrophysics Data System (ADS)
Mikaelian, Karnig O.
2016-02-01
We consider viscous fluids in spherical geometry, a lighter fluid supporting a heavier one. Chandrasekhar [Q. J. Mech. Appl. Math. 8, 1 (1955), 10.1093/qjmam/8.1.1] analyzed this unstable configuration providing the equations needed to find, numerically, the exact growth rates for the ensuing Rayleigh-Taylor instability. He also derived an analytic but approximate solution. We point out a weakness in his approximate dispersion relation (DR) and offer a somewhat improved one. A third DR, based on transforming a planar DR into a spherical one, suffers no unphysical predictions and compares reasonably well with the exact work of Chandrasekhar and a more recent numerical analysis of the problem [Terrones and Carrara, Phys. Fluids 27, 054105 (2015), 10.1063/1.4921648].
DOE Office of Scientific and Technical Information (OSTI.GOV)
Kawamura, K.; Okuwaki, A.; Verheyen, T.V.
In order to develop separation processes and analytical methods for aromatic carboxylic acids for the coal oxidation products, the separation behavior of aromatic carboxylic acids on a reversed-phase HPLC using eluent containing quaternary ammonium salt was optimized using the solvent gradient method. This method was applied for the analysis of Loy Yang coal oxidation products. It was confirmed that the analytical data using this method were consistent with those determined using gas chromatography.
Decreased Genetic Dosage of Hepatic Yin Yang 1 Causes Diabetic-Like Symptoms
Verdeguer, Francisco; Blättler, Sharon M.; Cunningham, John T.; Hall, Jessica A.; Chim, Helen
2014-01-01
Insulin sensitivity in liver is characterized by the ability of insulin to efficiently inhibit glucose production and fatty acid oxidation as well as promote de novo lipid biosynthesis. Specific dysregulation of glucose and lipid metabolism in liver is sufficient to cause insulin resistance and type 2 diabetes; this is seen by a selective inability of insulin to suppress glucose production while remaining insulin-sensitive to de novo lipid biosynthesis. We have previously shown that the transcription factor Yin Yang 1 (YY1) controls diabetic-linked glucose and lipid metabolism gene sets in skeletal muscle, but whether liver YY1-targeted metabolic genes impact a diabetic phenotype is unknown. Here we show that decreased genetic dosage of YY1 in liver causes insulin resistance, hepatic lipid accumulation, and dyslipidemia. Indeed, YY1 liver-specific heterozygous mice exhibit blunted activation of hepatic insulin signaling in response to insulin. Mechanistically, YY1, through direct recruitment to promoters, functions as a suppressor of genes encoding for metabolic enzymes of the gluconeogenic and lipogenic pathways and as an activator of genes linked to fatty acid oxidation. These counterregulatory transcriptional activities make targeting hepatic YY1 an attractive approach for treating insulin-resistant diabetes. PMID:24467246
How nonperturbative is the infrared regime of Landau gauge Yang-Mills correlators?
NASA Astrophysics Data System (ADS)
Reinosa, U.; Serreau, J.; Tissier, M.; Wschebor, N.
2017-07-01
We study the Landau gauge correlators of Yang-Mills fields for infrared Euclidean momenta in the context of a massive extension of the Faddeev-Popov Lagrangian which, we argue, underlies a variety of continuum approaches. Standard (perturbative) renormalization group techniques with a specific, infrared-safe renormalization scheme produce so-called decoupling and scaling solutions for the ghost and gluon propagators, which correspond to nontrivial infrared fixed points. The decoupling fixed point is infrared stable and weakly coupled, while the scaling fixed point is unstable and generically strongly coupled except for low dimensions d →2 . Under the assumption that such a scaling fixed point exists beyond one-loop order, we find that the corresponding ghost and gluon scaling exponents are, respectively, 2 αF=2 -d and 2 αG=d at all orders of perturbation theory in the present renormalization scheme. We discuss the relation between the ghost wave function renormalization, the gluon screening mass, the scale of spectral positivity violation, and the gluon mass parameter. We also show that this scaling solution does not realize the standard Becchi-Rouet-Stora-Tyutin symmetry of the Faddeev-Popov Lagrangian. Finally, we discuss our findings in relation to the results of nonperturbative continuum methods.
Perturbative tests for a large-N reduced model of {N} = {4} super Yang-Mills theory
NASA Astrophysics Data System (ADS)
Ishiki, Goro; Shimasaki, Shinji; Tsuchiya, Asato
2011-11-01
We study a non-perturbative formulation of {N} = {4} super Yang-Mills theory (SYM) on R × S 3 in the planar limit proposed in arXiv:0807.2352. This formulation is based on the large- N reduction, and the theory can be described as a particular large- N limit of the plane wave matrix model (PWMM), which is obtained by dimensionally reducing the original theory over S 3. In this paper, we perform some tests for this proposal. We construct an operator in the PWMM that corresponds to the Wilson loop in SYM in the continuum limit and calculate the vacuum expectation value of the operator for the case of the circular contour. We find that our result indeed agrees with the well-known result first obtained by Erickson, Semenoff and Zarembo. We also compute the beta function at the 1-loop level based on this formulation and see that it is indeed vanishing.
The Ethics of Clinical Care and the Ethics of Clinical Research: Yin and Yang.
Kowalski, Charles J; Hutchinson, Raymond J; Mrdjenovich, Adam J
2017-02-01
The Belmont Report's distinction between research and the practice of accepted therapy has led various authors to suggest that these purportedly distinct activities should be governed by different ethical principles. We consider some of the ethical consequences of attempts to separate the two and conclude that separation fails along ontological, ethical, and epistemological dimensions. Clinical practice and clinical research, as with yin and yang, can be thought of as complementary forces interacting to form a dynamic system in which the whole exceeds the sum of its parts. Just as effective clinical practice cannot exist without clinical research, meaningful clinical research requires the context of clinical practice. We defend this thesis by triangulation, that is, by outlining how multiple investigators have reached this conclusion on the basis of varied theoretical and applied approaches. More confidence can be placed in a result if different methods/viewpoints have led to that result. © The Author 2017. Published by Oxford University Press, on behalf of the Journal of Medicine and Philosophy Inc. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.
N=2 supersymmetric quantum mechanics of N Lieb-Liniger-Yang bosons on a line
NASA Astrophysics Data System (ADS)
Mateos Guilarte, J.; Moreno Mosquera, A.
2017-02-01
A supersymmetric generalization of the Lieb-Liniger-Yang dynamics governing N massive bosons moving on a line with delta interactions among them at coinciding points is developed. The analysis of the delicate balance between integrability and-supersymmetry, starting from the exactly solvable non-supersymmetric LLY system, is one of the paper main concerns. Two extreme regimes of the N parameter are explored: 1) For few bosons we fall in the realm of supersymmetric quantum mechanics with a short number of degrees of freedom, e.g., the SUSY Pösch-Teller potentials if N = 1 . 2) For large N we deal with supersymmetric extensions of many-body systems in the thermodynamic limit akin, e.g., to the supersymmetric Calogero-Sutherland systems. Emphasis will be put in the investigation of the ground-state structure of these quantum mechanical systems enjoying {N}=2 extended supersymmetry without spoiling integrability. The decision about wether or not supersymmetry is spontaneously broken, a central question in SUSY quantum mechanics determined from the ground-state structure, is another goal of the paper.
Low mass SN Ia and the late light curve
DOE Office of Scientific and Technical Information (OSTI.GOV)
Colgate, S.A.; Fryer, C.L.; Hand, K.P.
1995-12-31
The late bolometric light curves of type Ia supernovae, when measured accurately over several years, show an exponential decay with a 56d half-life over a drop in luminosity of 8 magnitudes (10 half-lives). The late-time light curve is thought to be governed by the decay of Co{sup 56}, whose 77d half-life must then be modified to account for the observed decay time. Two mechanisms, both relying upon the positron fraction of the Co{sup 56} decay, have been proposed to explain this modification. One explanation requires a large amount of emission at infra-red wavelengths where it would not be detected. Themore » other explanation has proposed a progressive transparency or leakage of the high energy positrons (Colgate, Petschek and Kriese, 1980). For the positrons to leak out of the expanding nebula at the required rate necessary to produce the modified 56d exponential, the mass of the ejecta from a one foe (10{sup 51} erg in kinetic energy) explosion must be small, M{sub ejec} = 0.4M{sub {circle_dot}} with M{sub ejec} {proportional_to} KE{sup 0.5}. Thus, in this leakage explanation, any reasonable estimate of the total energy of the explosion requires that the ejected mass be very much less than the Chandrasekhar mass of 1.4M{sub {circle_dot}}. This is very difficult to explain with the ``canonical`` Chandrasekhar-mass thermonuclear explosion that disintegrates the original white dwarf star. This result leads us to pursue alternate mechanisms of type Ia supernovae. These mechanisms include sub-Chandrasekhar thermonuclear explosions and the accretion induced collapse of Chandrasekhar mass white dwarfs. We will summarize the advantages and disadvantages of both mechanisms with considerable detail spent on our new accretion induced collapse simulations. These mechanisms lead to lower Ni{sup 56} production and hence result in type Ia supernovae with luminosities decreased down to {approximately} 50% that predicted by the ``standard`` model.« less
In Vivo Chromatin Targets of the Transcription Factor Yin Yang 2 in Trophoblast Stem Cells
Pérez-Palacios, Raquel; Macías-Redondo, Sofía; Climent, María; Contreras-Moreira, Bruno; Muniesa, Pedro; Schoorlemmer, Jon
2016-01-01
Background Yin Yang 2 (YY2) is a zinc finger protein closely related to the well-characterized Yin Yang 1 (YY1). YY1 is a DNA-binding transcription factor, with defined functions in multiple developmental processes, such as implantation, cell differentiation, X inactivation, imprinting and organogenesis. Yy2 has been treated as a largely immaterial duplication of Yy1, as they share high homology in the Zinc Finger-region and similar if not identical in vitro binding sites. In contrast to these similarities, gene expression alterations in HeLa cells with attenuated levels of either Yy1 or Yy2 were to some extent gene-specific. Moreover, the chromatin binding sites for YY2, except for its association with transposable retroviral elements (RE) and Endogenous Retroviral Elements (ERVs), remain to be identified. As a first step towards defining potential Yy2 functions matching or complementary to Yy1, we considered in vivo DNA binding sites of YY2 in trophoblast stem (TS) cells. Results We report the presence of YY2 protein in mouse-derived embryonic stem (ES) and TS cell lines. Following up on our previous report on ERV binding by YY2 in TS cells, we investigated the tissue-specificity of REX1 and YY2 binding and confirm binding to RE/ERV targets in both ES cells and TS cells. Because of the higher levels of expression, we chose TS cells to understand the role of Yy2 in gene and chromatin regulation. We used in vivo YY2 association as a measure to identify potential target genes. Sequencing of chromatin obtained in chromatin-immunoprecipitation (ChIP) assays carried out with αYY2 serum allowed us to identify a limited number of chromatin targets for YY2. Some putative binding sites were validated in regular ChIP assays and gene expression of genes nearby was altered in the absence of Yy2. Conclusions YY2 binding to ERVs is not confined to TS cells. In vivo binding sites share the presence of a consensus binding motif. Selected sites were uniquely bound by YY2 as
Mo, Raorao; Yang, Ding; Wang, Guoquan; Li, Weihai
2017-06-11
A new nemourid species, Amphinemura yao sp. nov. is described from the Daoyao Mountains of Guangxi Zhuang Autonomous Region of southern China. Amphinemura ancistroidea Li & Yang, 2007 is newly recorded from Guangxi and the female is described for the first time including the internal vaginal complex. The new species is compared with related taxa.
Li, Ming-Song; Liu, Zhenzhen; Liu, Jin-Qing; Zhu, Xiaotong; Liu, Zhihao; Bai, Xue-Feng
2015-01-01
Accumulating evidences from animal studies have indicated that both endogenous and exogenous IL-27, an IL-12 family of cytokine, can increase antitumor T-cell activities and inhibit tumor growth. IL-27 can modulate Treg responses, and program effector T cells into a unique T-effector stem cell (TSEC) phenotype, which enhances T-cell survival in the tumor microenvironment. However, animal studies also suggest that IL-27 induces molecular pathways such as IL-10, PD-L1 and CD39, which may downregulate tumor-specific T-cell responses. In this review paper, we will discuss the Yin and Yang aspects of IL-27 in the induction of tumor-specific T-cell responses, and the potential impacts of these functions of IL-27 in the design of cancer immunotherapy.
Revisiting the phase transition of AdS-Maxwell-power-Yang-Mills black holes via AdS/CFT tools
NASA Astrophysics Data System (ADS)
El Moumni, H.
2018-01-01
In the present work we investigate the Van der Waals-like phase transition of AdS black hole solution in the Einstein-Maxwell-power-Yang-Mills gravity (EMPYM) via different approaches. After reconsidering this phase structure in the entropy-thermal plane, we recall the nonlocal observables such as holographic entanglement entropy and two point correlation function to show that the both observables exhibit a Van der Waals-like behavior as the case of the thermal entropy. By checking the Maxwell's equal area law and calculating the critical exponent for different values of charge C and nonlinearity parameter q we confirm that the first and the second order phases persist in the holographic framework. Also the validity of the Maxwell law is governed by the proximity to the critical point.
NASA Astrophysics Data System (ADS)
Nishino, Hitoshi; Rajpoot, Subhash
2016-05-01
We present electric-magnetic (EM)-duality formulations for non-Abelian gauge groups with N =1 supersymmetry in D =3 +3 and 5 +5 space-time dimensions. We show that these systems generate self-dual N =1 supersymmetric Yang-Mills (SDSYM) theory in D =2 +2 . For a N =2 supersymmetric EM-dual system in D =3 +3 , we have the Yang-Mills multiplet (Aμ I,λA I) and a Hodge-dual multiplet (Bμν ρ I,χA I) , with an auxiliary tensors Cμν ρ σ I and Kμ ν. Here, I is the adjoint index, while A is for the doublet of S p (1 ). The EM-duality conditions are Fμν I=(1 /4 !)ɛμν ρ σ τ λGρσ τ λ I with its superpartner duality condition λA I=-χA I . Upon appropriate dimensional reduction, this system generates SDSYM in D =2 +2 . This system is further generalized to D =5 +5 with the EM-duality condition Fμν I=(1 /8 !)ɛμν ρ1⋯ρ8Gρ1⋯ρ8 I with its superpartner condition λI=-χI . Upon appropriate dimensional reduction, this theory also generates SDSYM in D =2 +2 . As long as we maintain Lorentz covariance, D =5 +5 dimensions seems to be the maximal space-time dimensions that generate SDSYM in D =2 +2 . Namely, EM-dual system in D =5 +5 serves as the Master Theory of all supersymmetric integrable models in dimensions 1 ≤D ≤3 .
Perturbative tests for a large-N reduced model of mathcal{N} = {4} super Yang-Mills theory
NASA Astrophysics Data System (ADS)
Ishiki, Goro; Shimasaki, Shinji; Tsuchiya, Asato
2012-02-01
We study a non-perturbative formulation of mathcal{N} = {4} super Yang-Mills theory (SYM) on R × S 3 in the planar limit proposed in arXiv:0807.2352. This formulation is based on the large- N reduction, and the theory can be described as a particular large- N limit of the plane wave matrix model (PWMM), which is obtained by dimensionally reducing the original theory over S 3. In this paper, we perform some tests for this proposal. We construct an operator in the PWMM that corresponds to the Wilson loop in SYM in the continuum limit and calculate the vacuum expectation value of the operator for the case of the circular contour. We find that our result indeed agrees with the well-known result first obtained by Erickson, Semenoff and Zarembo. We also compute the beta function at the 1-loop level based on this formulation and see that it is indeed vanishing.
Yin Yang 1 Is a Critical Repressor of Matrix Metalloproteinase-9 Expression in Brain Neurons*
Rylski, Marcin; Amborska, Renata; Zybura, Katarzyna; Mioduszewska, Barbara; Michaluk, Piotr; Jaworski, Jacek; Kaczmarek, Leszek
2008-01-01
Membrane depolarization controls long lasting adaptive neuronal changes in brain physiology and pathology. Such responses are believed to be gene expression-dependent. Notably, however, only a couple of gene repressors active in nondepolarized neurons have been described. In this study, we show that in the unstimulated rat hippocampus in vivo, as well as in the nondepolarized brain neurons in primary culture, the transcriptional regulator Yin Yang 1 (YY1) is bound to the proximal Mmp-9 promoter and strongly represses Mmp-9 transcription. Furthermore, we demonstrate that monoubiquitinated and CtBP1 (C-terminal binding protein 1)-bound YY1 regulates Mmp-9 mRNA synthesis in rat brain neurons controlling its transcription apparently via HDAC3-dependent histone deacetylation. In conclusion, our data suggest that YY1 exerts, via epigenetic mechanisms, a control over neuronal expression of MMP-9. Because MMP-9 has recently been shown to play a pivotal role in physiological and pathological neuronal plasticity, YY1 may be implicated in these phenomena as well. PMID:18940814
Quench dynamics in superconducting nanojunctions: Metastability and dynamical Yang-Lee zeros
NASA Astrophysics Data System (ADS)
Souto, R. Seoane; Martín-Rodero, A.; Yeyati, A. Levy
2017-10-01
We study the charge transfer dynamics following the formation of a phase or voltage biased superconducting nanojunction using a full counting statistics analysis. We demonstrate that the evolution of the zeros of the generating function allows one to identify the population of different many body states much in the same way as the accumulation of Yang-Lee zeros of the partition function in equilibrium statistical mechanics is connected to phase transitions. We give an exact expression connecting the dynamical zeros to the charge transfer cumulants and discuss when an approximation based on "dominant" zeros is valid. We show that, for generic values of the parameters, the system gets trapped into a metastable state characterized by a nonequilibrium population of the many body states which is dependent on the initial conditions. We study in particular the effect of the switching rates in the dynamics showing that, in contrast to intuition, the deviation from thermal equilibrium increases for the slower rates. In the voltage biased case the steady state is reached independent of the initial conditions. Our method allows us to obtain accurate results for the steady state current and noise in quantitative agreement with steady state methods developed to describe the multiple Andreev reflections regime. Finally, we discuss the system dynamics after a sudden voltage drop showing the possibility of tuning the many body states population by an appropriate choice of the initial voltage, providing a feasible experimental way to access the quench dynamics and control the state of the system.
Emerging geometry from maximally super-symmetric Yang-Mills theory
NASA Astrophysics Data System (ADS)
Vazquez, Samuel Enrique
In this thesis, we explore the emergence of space-time geometry, and string theory physics from N = 4 supersymmetric Yang-Mills (SYM) theory with gauge group U(N). This is done in the context of the anti-de-Sitter/conformal field theory correspondence (AdS/CFT). The main results of this thesis are the following. First, we study single trace perturbations around generic 1/2 BPS states of the theory. We do this in the large N limit, and at one-loop in the 't-Hooft coupling. We show how these states can be mapped to dynamical lattices with boson statistics and periodic boundary conditions. By dynamical, we mean that the total boson occupation number is not conserved in general. Then, we show how to derive an effective sigma model for these systems which coincides with the Polyakov action of a probe string on a 1/2 BPS geometry (in the fast string limit). Secondly, we study non-supersymmetric perturbations of the vacuum which give rise to bosonic lattices with open boundary conditions. We also do this in the large N limit, and at one-loop in the 't-Hooft coupling. We show that these states are dual to open strings on D3-branes known as "Giant Gravitons". These lattice systems are also dynamical, but in some special cases, we show that we get an integrable spin chain with open boundary conditions. Next, we study single trace perturbations at strong coupling. We do this by taking a "dilute gas" approximation. We derive an all-loop result for the dispersion relation of the "magnons" which coincides with previous conjectures in the literature. What is more, we derive the geometrical picture of the so-called "giant magnon" string solution of Hofman and Maldacena, directly from the field theory. Finally, we explore the question of classical integrability of open strings on D-branes. In particular, we study the case of the giant gravitons, and compare the integrable structures on both sides of the AdS/CFT correspondence.
NASA Astrophysics Data System (ADS)
Bergner, Georg; Piemonte, Stefano
2018-04-01
Non-Abelian gauge theories with fermions transforming in the adjoint representation of the gauge group (AdjQCD) are a fundamental ingredient of many models that describe the physics beyond the Standard Model. Two relevant examples are N =1 supersymmetric Yang-Mills (SYM) theory and minimal walking technicolor, which are gauge theories coupled to one adjoint Majorana and two adjoint Dirac fermions, respectively. While confinement is a property of N =1 SYM, minimal walking technicolor is expected to be infrared conformal. We study the propagators of ghost and gluon fields in the Landau gauge to compute the running coupling in the MiniMom scheme. We analyze several different ensembles of lattice Monte Carlo simulations for the SU(2) adjoint QCD with Nf=1 /2 ,1 ,3 /2 , and 2 Dirac fermions. We show how the running of the coupling changes as the number of interacting fermions is increased towards the conformal window.
Yin yang 1 is a novel regulator of pulmonary fibrosis.
Lin, Xin; Sime, Patricia J; Xu, Haodong; Williams, Marc A; LaRussa, Larry; Georas, Steve N; Guo, Jia
2011-06-15
The differentiation of fibroblasts into myofibroblasts is a cardinal feature of idiopathic pulmonary fibrosis (IPF). The transcription factor Yin Yang 1 (YY1) plays a role in the proliferation and differentiation of diverse cell types, but its role in fibrotic lung diseases is not known. To elucidate the mechanism by which YY1 regulates fibroblast differentiation and lung fibrosis. Lung fibroblasts were cultured with transforming growth factor (TGF)-β or tumor necrosis factor-α. Nuclear factor (NF)-κB, YY1, and α-smooth muscle actin (SMA) were determined in protein, mRNA, and promoter reporter level. Lung fibroblasts and lung fibrosis were assessed in a partial YY1-deficient mouse and a YY1(f/f) conditional knockout mouse after being exposed to silica or bleomycin. TGF-β and tumor necrosis factor-α up-regulated YY1 expression in lung fibroblasts. TGF-β-induced YY1 expression was dramatically decreased by an inhibitor of NF-κB, which blocked I-κB degradation. YY1 is significantly overexpressed in both human IPF and murine models of lung fibrosis, including in the aggregated pulmonary fibroblasts of fibrotic foci. Furthermore, the mechanism of fibrogenesis is that YY1 can up-regulate α-SMA expression in pulmonary fibroblasts. YY1-deficient (YY1(+/-)) mice were significantly protected from lung fibrosis, which was associated with attenuated α-SMA and collagen expression. Finally, decreasing YY1 expression through instilled adenovirus-cre in floxed-YY1(f/f) mice reduced lung fibrosis. YY1 is overexpressed in fibroblasts in both human IPF and murine models in a NF-κB-dependent manner, and YY1 regulates fibrogenesis at least in part by increasing α-SMA and collagen expression. Decreasing YY1 expression may provide a new therapeutic strategy for pulmonary fibrosis.
Plasma drag on a dust grain due to Coulomb collisions
NASA Technical Reports Server (NTRS)
Northrop, T. G.; Birmingham, T. J.
1990-01-01
Expressions are given for the drag due to Coulomb collisions on a charged dust grain moving through a plasma. The commonly used Chandrasekhar (1943) result does not include large scattering angles or plasma collective effects. An equation given by Morfill et al. (1980) which does include large scattering angles, is limited to one-dimensional plasma particle motion and can give at least an order of magnitude too much drag. This paper also makes use of an analogy between the drag problem and problems in electrostatics. This analogy permits generalization to any isotropic plasma of an observation made by Chandrasekhar for a Maxwellian, namely, that the drag is independent of the presence or absence of plasma particles moving faster than the grain. Finally, the contribution of plasma collective effects to the drag is studied with the inclusion of large scattering angles.
NASA Technical Reports Server (NTRS)
Sparks, W. M.; Endal, A. S.
1980-01-01
The evolution of a Population I star of 15 solar masses is described from the carbon shell burning stage to the formation and collapse of an iron core. An unusual aspect of the evolution is that neon ignition occurs off-center and neon burning propagates inward by a series of shell flashes. The extent of the core burning is generally smaller than the Chandrasekhar mass, so that most of the nuclear energy generation occurs in shell sources. Because of degeneracy and the influence of rapid convective mixing, these shell sources are unstable and the core goes through large excursions in temperature and density. The small core also causes the shell sources to converge into a narrow mass region slightly above the Chandrasekhar mass. Thus, the final nucleosynthesis yields are generally small, with silicon being most strongly enhanced with respect to solar system abundances.
Generalization of Faddeev-Popov rules in Yang-Mills theories: N = 3,4 BRST symmetries
NASA Astrophysics Data System (ADS)
Reshetnyak, Alexander
2018-01-01
The Faddeev-Popov rules for a local and Poincaré-covariant Lagrangian quantization of a gauge theory with gauge group are generalized to the case of an invariance of the respective quantum actions, S(N), with respect to N-parametric Abelian SUSY transformations with odd-valued parameters λp, p = 1,…,N and generators sp: spsq + sqsp = 0, for N = 3, 4, implying the substitution of an N-plet of ghost fields, Cp, instead of the parameter, ξ, of infinitesimal gauge transformations: ξ = Cpλ p. The total configuration spaces of fields for a quantum theory of the same classical model coincide in the N = 3 and N = 4 symmetric cases. The superspace of N = 3 SUSY irreducible representation includes, in addition to Yang-Mills fields 𝒜μ, (3 + 1) ghost odd-valued fields Cp, B̂ and 3 even-valued Bpq for p, q = 1, 2, 3. To construct the quantum action, S(3), by adding to the classical action, S0(𝒜), of an N = 3-exact gauge-fixing term (with gauge fermion), a gauge-fixing procedure requires (1 + 3 + 3 + 1) additional fields, Φ¯(3): antighost C¯, 3 even-valued Bp, 3 odd-valued B̂pq and Nakanishi-Lautrup B fields. The action of N = 3 transformations on new fields as N = 3-irreducible representation space is realized. These transformations are the N = 3 BRST symmetry transformations for the vacuum functional, Z3(0) =∫dΦ(3)dΦ¯(3)exp{(ı/ℏ)S(3)}. The space of all fields (Φ(3),Φ¯(3)) proves to be the space of an irreducible representation of the fields Φ(4) for N = 4-parametric SUSY transformations, which contains, in addition to 𝒜μ the (4 + 6 + 4 + 1) ghost-antighost, Cr = (Cp,C¯), even-valued, Brs = -Bsr = (Bpq,Bp4 = Bp), odd-valued B̂r = (B̂,B̂pq) and B fields. The quantum action is constructed by adding to S0(𝒜) an N = 4-exact gauge-fixing term with a gauge boson, F(4). The N = 4 SUSY transformations are by N = 4 BRST transformations for the vacuum functional, Z4(0) =∫dΦ(4)exp{(ı/ℏ)S(4)}. The procedures are valid for
Dyons and dyonic black holes in su (N ) Einstein-Yang-Mills theory in anti-de Sitter spacetime
NASA Astrophysics Data System (ADS)
Shepherd, Ben L.; Winstanley, Elizabeth
2016-03-01
We present new spherically symmetric, dyonic soliton and black hole solutions of the su (N ) Einstein-Yang-Mills equations in four-dimensional asymptotically anti-de Sitter spacetime. The gauge field has nontrivial electric and magnetic components and is described by N -1 magnetic gauge field functions and N -1 electric gauge field functions. We explore the phase space of solutions in detail for su (2 ) and su (3 ) gauge groups. Combinations of the electric gauge field functions are monotonic and have no zeros; in general the magnetic gauge field functions may have zeros. The phase space of solutions is extremely rich, and we find solutions in which the magnetic gauge field functions have more than fifty zeros. Of particular interest are solutions for which the magnetic gauge field functions have no zeros, which exist when the negative cosmological constant has sufficiently large magnitude. We conjecture that at least some of these nodeless solutions may be stable under linear, spherically symmetric, perturbations.
a New Hybrid Yin-Yang Swarm Optimization Algorithm for Uncapacitated Warehouse Location Problems
NASA Astrophysics Data System (ADS)
Heidari, A. A.; Kazemizade, O.; Hakimpour, F.
2017-09-01
Yin-Yang-pair optimization (YYPO) is one of the latest metaheuristic algorithms (MA) proposed in 2015 that tries to inspire the philosophy of balance between conflicting concepts. Particle swarm optimizer (PSO) is one of the first population-based MA inspired by social behaviors of birds. In spite of PSO, the YYPO is not a nature inspired optimizer. It has a low complexity and starts with only two initial positions and can produce more points with regard to the dimension of target problem. Due to unique advantages of these methodologies and to mitigate the immature convergence and local optima (LO) stagnation problems in PSO, in this work, a continuous hybrid strategy based on the behaviors of PSO and YYPO is proposed to attain the suboptimal solutions of uncapacitated warehouse location (UWL) problems. This efficient hierarchical PSO-based optimizer (PSOYPO) can improve the effectiveness of PSO on spatial optimization tasks such as the family of UWL problems. The performance of the proposed PSOYPO is verified according to some UWL benchmark cases. These test cases have been used in several works to evaluate the efficacy of different MA. Then, the PSOYPO is compared to the standard PSO, genetic algorithm (GA), harmony search (HS), modified HS (OBCHS), and evolutionary simulated annealing (ESA). The experimental results demonstrate that the PSOYPO can reveal a better or competitive efficacy compared to the PSO and other MA.
Chen, Suhong; Lv, Guiyuan; Huang, Mincong; Su, Jie; Fang, Hui; Mou, Xiuhua
2011-06-01
To observe the effects of three traditional Chinese medicine (TCM) such as Amomi Fructus Rotundus, Perillae Folium and Angelicae Dahuricae Radix on lung-yang deficiency rats induced by compound factors. Lung-yang deficiency rats were established with three-factor combination, such as smoking (exogenous evil effect on lung), swimming in common and ice water (cold body and exhaustoin) and drinking ice water (inhale cold). Meanwhile, rats were given water extracts of the three TCM by intragastric administration for 24 days everyday. Indexes such as general behavior, weight, rectal temperature, back temperature and grip strength were observed. Blood was collected to determine NO, IgG in blood serum. Lung and heart were dissected to measure organs index. The water extracts of Amomi Fructrs Rotundus, Perillae Folium and Angelicae Dahuricae Radix could markedly heighten weight, back temperature, grip strength, content of IgG in blood serum, reduce content of NO in blood serum, lung index and heart index. The water extracts of Amomi Fructrs Rotundus and Perillae Folium could heighten rectal temperature. Amomi Fructrs Rotundus, Perillae Folium and Angelicae Dahuricae Radix were TCM with pungent-flavor, warm-nature and meridian tropism in lung, which could improve the symptoms of physique emaciation, aversion to cold of the back, weary and acratia and so on. It provides an important reference for the regularity of the properties theories about pungent-flavor, warm-nature and meridian tropism in lung.
Zhu, G; Pan, L; Zhao, Y; Zhang, X; Wang, F; Yu, Y; Fan, W; Liu, Q; Zhang, S; Li, M
2017-04-01
In tritrophic 'plants-herbivores-natural enemies' systems, there are relatively few reports concerning the role(s) of kairomones in pupal parasitism. Chouioia cunea Yang (Hymenoptera: Eulophidae), an endoparasitic chalcid wasp, parasitizes pupae of the fall webworm (Hyphantria cunea Drury). The role of host-related kairomones was investigated using electroantennogram (EAG) and behavioral techniques. Chemicals from some host stages (pupae) and host by-products (frass), induced arrestment behavior of female parasitoids, while chemicals from prepupae, were inactive. Gas chromatography-mass spectrometry analysis of volatiles collected from pupae, frass and prepupae using solid-phase microextration revealed seven compounds with carbon chain lengths ranging from C4 to C20. All of the chemicals elicited significant EAG responses in C. cunea. Y-tube olfactometer bioassays demonstrated a significant positive response of mated female C. cunea to 1-dodecene. These data provide a better understanding of the host location mechanisms of pupal parasitoid.
NASA Astrophysics Data System (ADS)
Huang, Xian-Bin; Yang, Li-Bing; Li, Jing; Zhou, Shao-Tong; Ren, Xiao-Dong; Zhang, Si-Qun; Dan, Jia-Kun; Cai, Hong-Chun; Duan, Shu-Chao; Chen, Guang-Hua; Zhang, Zheng-Wei; Ouyang, Kai; Li, Jun; Zhang, Zhao-Hui; Zhou, Rong-Guo; Wang, Gui-Lin
2012-05-01
We investigated the radiation characteristics and implosion dynamics of low-wire-number cylindrical tungsten wire array Z-pinches on the YANG accelerator with a peak current 0.8-1.1 MA and a rising time ~ 90 ns. The arrays are made up of (8-32) × 5 μm wires 6/10 mm in diameter and 15 mm in height. The highest X-ray power obtained in the experiments was about 0.37 TW with the total radiation energy ~ 13 kJ and the energy conversion efficiency ~ 9% (24 × 5 μm wires, 6 mm in diameter). Most of the X-ray emissions from tungsten Z-pinch plasmas were distributed in the spectral band of 100-600 eV, peaked at 250 and 375 eV. The dominant wavelengths of the wire ablation and the magneto-Rayleigh—Taylor instability were found and analyzed through measuring the time-gated self-emission and laser interferometric images. Through analyzing the implosion trajectories obtained by an optical streak camera, the run-in velocities of the Z-pinch plasmas at the end of the implosion phase were determined to be about (1.3-2.1) × 107 cm/s.
Beyond mean-field effects in Bloch Oscillations of cold atoms in an optical cavity
NASA Astrophysics Data System (ADS)
Venkatesh Balasubramanian, Prasanna; O'Dell, Duncan
2012-06-01
In our earlier publication [1] we proposed using Bloch oscillations of cold atoms inside an Fabry-Perot resonator for sensitive measurements of force. The analysis in [1] was performed using a coherent mean-field description for the atoms and the light. In the current work we extend this description substantially by including the effects of fluctuations in both the atomic and light fields. This analysis is used to set realistic limits on the precision to which the force can be measured. We also make contact with the optomechanical description of the combined atom-cavity system which has proved so successful for describing recent pioneering experiments [2].[4pt] [1] B. Prasanna Venkatesh et al, Phys. Rev. A 80, 063834 (2009).[0pt] [2] S. Gupta et al, Phys. Rev. Lett. 99, 213601 (2007); F.Brennecke et al, Science 322, 235 (2008).
STS-93/ Chandra Science Briefing
NASA Technical Reports Server (NTRS)
1999-01-01
This video shows a press briefing, reviewing the type of information which scientist hope to get from the Chandra X-ray Telescope. The telescope is scheduled to be launched during the STS-93 flight. The participants in the briefing are: Don Savage, of NASA Headquarters; Ed Weiler, Associate Administrator for Space Sciences; Alan Bunner, Chandra Project Scientist and Michael Turner, an astrophysicist at the University of Chicago. After the introduction by Mr. Savage, the broad scientific goals of the Chandra mission are reviewed by Dr. Weiler. This is followed by an acknowledgement of many of the people who participated in the development of the Chandra Telescope. This is followed by a discussion of the astrophysics and the information which the telescope should provide. Mrs. Chandrasekhar, the widow of Subrahmanyan Chandrasekhar, was in the audience. She was introduced and spoke briefly about the late Nobel Laureate astrophysicist.
Quantum vacua of 2d maximally supersymmetric Yang-Mills theory
NASA Astrophysics Data System (ADS)
Koloğlu, Murat
2017-11-01
We analyze the classical and quantum vacua of 2d N=(8,8) supersymmetric Yang-Mills theory with SU( N) and U( N) gauge group, describing the worldvolume interactions of N parallel D1-branes with flat transverse directions {R}^8 . We claim that the IR limit of the SU( N) theory in the superselection sector labeled M (mod N) — identified with the internal dynamics of ( M, N)-string bound states of the Type IIB string theory — is described by the symmetric orbifold N=(8,8) sigma model into ({R}^8)^{D-1}/S_D when D = gcd( M, N) > 1, and by a single massive vacuum when D = 1, generalizing the conjectures of E. Witten and others. The full worldvolume theory of the D1-branes is the U( N) theory with an additional U(1) 2-form gauge field B coming from the string theory Kalb-Ramond field. This U( N) + B theory has generalized field configurations, labeled by the Z-valued generalized electric flux and an independent {Z}_N -valued 't Hooft flux. We argue that in the quantum mechanical theory, the ( M, N)-string sector with M units of electric flux has a {Z}_N -valued discrete θ angle specified by M (mod N) dual to the 't Hooft flux. Adding the brane center-of-mass degrees of freedom to the SU( N) theory, we claim that the IR limit of the U( N) + B theory in the sector with M bound F-strings is described by the N=(8,8) sigma model into {Sym}^D({R}^8) . We provide strong evidence for these claims by computing an N=(8,8) analog of the elliptic genus of the UV gauge theories and of their conjectured IR limit sigma models, and showing they agree. Agreement is established by noting that the elliptic genera are modular-invariant Abelian (multi-periodic and meromorphic) functions, which turns out to be very restrictive.
Doubled lattice Chern-Simons-Yang-Mills theories with discrete gauge group
NASA Astrophysics Data System (ADS)
Caspar, S.; Mesterházy, D.; Olesen, T. Z.; Vlasii, N. D.; Wiese, U.-J.
2016-11-01
We construct doubled lattice Chern-Simons-Yang-Mills theories with discrete gauge group G in the Hamiltonian formulation. Here, these theories are considered on a square spatial lattice and the fundamental degrees of freedom are defined on pairs of links from the direct lattice and its dual, respectively. This provides a natural lattice construction for topologically-massive gauge theories, which are invariant under parity and time-reversal symmetry. After defining the building blocks of the doubled theories, paying special attention to the realization of gauge transformations on quantum states, we examine the dynamics in the group space of a single cross, which is spanned by a single link and its dual. The dynamics is governed by the single-cross electric Hamiltonian and admits a simple quantum mechanical analogy to the problem of a charged particle moving on a discrete space affected by an abstract electromagnetic potential. Such a particle might accumulate a phase shift equivalent to an Aharonov-Bohm phase, which is manifested in the doubled theory in terms of a nontrivial ground-state degeneracy on a single cross. We discuss several examples of these doubled theories with different gauge groups including the cyclic group Z(k) ⊂ U(1) , the symmetric group S3 ⊂ O(2) , the binary dihedral (or quaternion) group D¯2 ⊂ SU(2) , and the finite group Δ(27) ⊂ SU(3) . In each case the spectrum of the single-cross electric Hamiltonian is determined exactly. We examine the nature of the low-lying excited states in the full Hilbert space, and emphasize the role of the center symmetry for the confinement of charges. Whether the investigated doubled models admit a non-Abelian topological state which allows for fault-tolerant quantum computation will be addressed in a future publication.
NASA Astrophysics Data System (ADS)
Di, Q.
2013-12-01
In recent years, deep prospecting method such as magnetotelluric and controlled source audio-frequency magnetotelluric develop rapidly, but the instruments almost monopolized by several big geophysical companies from the United States, Canada and Germany. From prospecting practice, foreign equipment adaptation on complicated geological conditions in China is unsatisfactory. As increasing of national strength, electromagnetic exploration system development independently is on the agenda. In the year of 2010, the institute of geology and geophysics, Chinese academy of sciences, took on one subject of the SinoProbe project, the research of surface Electromagnetic Prospecting (SEP) System, and has achieved some achievements. SEP is an independent research instrumentation system, which is available for MT, AMT and CSAMT soundings. After laboratory testing, in order to test SEP's performance in field, the yang-jia-zhang-zi molybdenum deposit area is selected for SEP experiment. All modules and components of SEP system have been tested, and the field ability of the whole system also has been tested. The experimental results show that SEP performance has reached the level of commercial instruments.
NASA Astrophysics Data System (ADS)
Gale, Charles; Jeon, Sangyong; Schenke, Björn; Tribedy, Prithwish; Venugopalan, Raju
2013-01-01
Anisotropic flow coefficients v1-v5 in heavy ion collisions are computed by combining a classical Yang-Mills description of the early time Glasma flow with the subsequent relativistic viscous hydrodynamic evolution of matter through the quark-gluon plasma and hadron gas phases. The Glasma dynamics, as realized in the impact parameter dependent Glasma (IP-Glasma) model, takes into account event-by-event geometric fluctuations in nucleon positions and intrinsic subnucleon scale color charge fluctuations; the preequilibrium flow of matter is then matched to the music algorithm describing viscous hydrodynamic flow and particle production at freeze-out. The IP-Glasma+MUSIC model describes well both transverse momentum dependent and integrated vn data measured at the Large Hadron Collider and the Relativistic Heavy Ion Collider. The model also reproduces the event-by-event distributions of v2, v3 and v4 measured by the ATLAS Collaboration. The implications of our results for better understanding of the dynamics of the Glasma and for the extraction of transport properties of the quark-gluon plasma are outlined.
Jobling, Rebekah; Stavropoulos, Dimitri James; Marshall, Christian R; Cytrynbaum, Cheryl; Axford, Michelle M; Londero, Vanessa; Moalem, Sharon; Orr, Jennifer; Rossignol, Francis; Lopes, Fatima Daniela; Gauthier, Julie; Alos, Nathalie; Rupps, Rosemarie; McKinnon, Margaret; Adam, Shelin; Nowaczyk, Malgorzata J M; Walker, Susan; Scherer, Stephen W; Nassif, Christina; Hamdan, Fadi F; Deal, Cheri L; Soucy, Jean-François; Weksberg, Rosanna; Macleod, Patrick; Michaud, Jacques L; Chitayat, David
2018-05-01
Chitayat-Hall syndrome, initially described in 1990, is a rare condition characterised by distal arthrogryposis, intellectual disability, dysmorphic features and hypopituitarism, in particular growth hormone deficiency. The genetic aetiology has not been identified. We identified three unrelated families with a total of six affected patients with the clinical manifestations of Chitayat-Hall syndrome. Through whole exome or whole genome sequencing, pathogenic variants in the MAGEL2 gene were identified in all affected patients. All disease-causing sequence variants detected are predicted to result in a truncated protein, including one complex variant that comprised a deletion and inversion. Chitayat-Hall syndrome is caused by pathogenic variants in MAGEL2 and shares a common aetiology with the recently described Schaaf-Yang syndrome. The phenotype of MAGEL2 -related disorders is expanded to include growth hormone deficiency as an important and treatable complication. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.
Tang, Xiao-Ran; Wang, Jing-Xia; Fu, Lu; Yao, Jun-Kai; Li, Si-Ming; Gao, Xue-Min; Zhang, Jian-Jun
2018-06-01
Menopausal women appear lipid metabolism disorder with the ovarian function decline and the estrogen levels decreased. Modern clinical usually use estrogen replacement therapy and with long time application with lots of side effect appear. Traditional Chinese medicine has more secure and effective methords,using warming Yang drugs and methods. And the previous study proves the Chinese medicine Astragali Complanati Semen water extraction has a good role in regulation of blood lipids. Because of the liver is the most important organ on regulating metabolism, therefore this study aimed to evaluate the effects of total flavonoids in Astragali Complanati Semen(TFS)on liverlipid level and ERα expressionon liver in hyperlipidemia rats with kidney-Yang deficiency pattern to explore the substance basis and mechanism of Astragali Complanati Semen in regulate lipid effect and clarify traditional Chinese medicine advantages and features. This experiment uses hyperlipidemia rats with kidney-Yang deficiency pattern with bilateral ovariectomized and fed with high fat diet for 6 weeks. And rats of sham operation group and model group rats were intragastrilly(ig) with saline, estrogen group were intragastrilly with estrogen(0.2 mg·kg⁻¹). And three TFS group were intragastrilly with TFS at dose 28.5, 57, 114 mg·kg⁻¹ for 8 weeks. At the same time, TC, TG, LDL-C,HDL-C liver weight, liver index, uterine weight, uterine index, serum estrogen level, FSH levels and liver pathology, liver estrogen receptor expression were detected, weighting and calculating their organ index. The experimental results compared with the model group, TFS 114 mg·kg⁻¹ decreased the level of liver TG ( P <0.05), TC ( P <0.001) and LDL-C ( P <0.001) and increased the level of HDL-C ( P <0.05). Compared with the model group, estrogen group increased the level of blood serum ( P <0.001) and decreased the level of FSH ( P <0.001). In addition, compared with sham operation group,model group decreased the
Three-dimensional polarization algebra.
R Sheppard, Colin J; Castello, Marco; Diaspro, Alberto
2016-10-01
If light is focused or collected with a high numerical aperture lens, as may occur in imaging and optical encryption applications, polarization should be considered in three dimensions (3D). The matrix algebra of polarization behavior in 3D is discussed. It is useful to convert between the Mueller matrix and two different Hermitian matrices, representing an optical material or system, which are in the literature. Explicit transformation matrices for converting the column vector form of these different matrices are extended to the 3D case, where they are large (81×81) but can be generated using simple rules. It is found that there is some advantage in using a generalization of the Chandrasekhar phase matrix treatment, rather than that based on Gell-Mann matrices, as the resultant matrices are of simpler form and reduce to the two-dimensional case more easily. Explicit expressions are given for 3D complex field components in terms of Chandrasekhar-Stokes parameters.
Hu, Wei; Qian, Xian; Guo, Feng; Zhang, Miaojia; Lyu, Chengyin; Tao, Juan; Gao, Zhong'en; Zhou, Zhengqiu
2014-01-01
Traditional Chinese medical treatment of primary Sjögren's syndrome has advantages over Western medicine in terms of fewer side effects and improved patient conditions. This study was a multicenter, randomized, double-blind, placebo-controlled clinical trial of the efficacy and safety of ShengJinRunZaoYangXue granules for the treatment of primary Sjögren's syndrome, including the symptoms of dry mouth and dry eye. We undertook a 6-week, double-blind, randomized trial involving 240 patients with primary Sjögren's syndrome at five centers in East China. A computer-generated randomization schedule assigned patients at a 2:1 ratio to receive either ShengJinRunZaoYangXue granules or placebo once daily. Patients and investigators were blinded to treatment allocation. The primary endpoints were the salivary flow rate, Schirmer test results, and sugar test results. Intention-to-treat and per-protocol analyses were performed. All 240 patients were randomly allocated to either the treatment group (n = 160, ShengJinRunZaoYangXue granules) or placebo group (n = 80) and were included in the intention-to-treat analysis. After program violation and loss to follow-up, a total of 199 patients were included in the per-protocol analysis. At six week, intention-to-treat and per-protocol analyses of the left-eye Schirmer I test results showed an improved difference of 1.36 mm/5 min (95% CI: 0.03 to 2.69 mm/5 min) and 1.35 mm/5 min (95% CI: 0.04 to 2.73 mm/5 min), respectively, and those of the right-eye Schirmer I test results showed an improved difference of 1.12 mm/5 min (95% CI: 0.02 to 2.22 mm/5 min) and 1.12 mm/5 min (95% CI: -0.02 to 2.27 mm/5 min), respectively. There was no significant difference between the two groups before treatment. After treatment, the between-group and within-group before-and-after paired comparison results were statistically significant (P < 0.05). Intention-to-treat and per-protocol analyses showed an improved salivary flow rate by 0.04 ml/15 min (95
DOE Office of Scientific and Technical Information (OSTI.GOV)
Baxter, J. Erik, E-mail: e.baxter@shu.ac.uk
We investigate dyonic black hole and dyon solutions of four-dimensional su(N) Einstein-Yang-Mills theory with a negative cosmological constant. We derive a set of field equations in this case, and prove the existence of non-trivial solutions to these equations for any integer N, with 2N − 2 gauge degrees of freedom. We do this by showing that solutions exist locally at infinity, and at the event horizon for black holes and the origin for solitons. We then prove that we can patch these solutions together regularly into global solutions that can be integrated arbitrarily far into the asymptotic regime. Our mainmore » result is to show that dyonic solutions exist in open sets in the parameter space, and hence that we can find non-trivial dyonic solutions in a number of regimes whose magnetic gauge fields have no zeros, which is likely important to the stability of the solutions.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Sato, Yushi; Nakasato, Naohito; Tanikawa, Ataru
2016-04-10
Mergers of carbon–oxygen (CO) white dwarfs (WDs) are considered to be one of the potential progenitors of type Ia supernovae (SNe Ia). Recent hydrodynamical simulations showed that the less massive (secondary) WD violently accretes onto the more massive (primary) one, carbon detonation occurs, the detonation wave propagates through the primary, and the primary finally explodes as a sub-Chandrasekhar mass SN Ia. Such an explosion mechanism is called the violent merger scenario. Based on the smoothed particle hydrodynamics simulations of merging CO WDs, we derived a critical mass ratio (q{sub cr}) leading to the violent merger scenario that is more stringent than previous results. Wemore » conclude that this difference mainly comes from the differences in the initial condition of whether or not the WDs are synchronously spinning. Using our new results, we estimated the brightness distribution of SNe Ia in the violent merger scenario and compared it with previous studies. We found that our new q{sub cr} does not significantly affect the brightness distribution. We present the direct outcome immediately following CO WD mergers for various primary masses and mass ratios. We also discussed the final fate of the central system of the bipolar planetary nebula Henize 2-428, which was recently suggested to be a double CO WD system whose total mass exceeds the Chandrasekhar-limiting mass, merging within the Hubble time. Even considering the uncertainties in the proposed binary parameters, we concluded that the final fate of this system is almost certainly a sub-Chandrasekhar mass SN Ia in the violent merger scenario.« less
Zhang, Xiu-Jing; Sun, Tian-Cai; Liu, Zi-Wang; Wang, Feng-Jiao; Wang, Yong-De; Liu, Jing
2017-11-01
To collect visualized proof of Tianmagouteng particles (TMGTP) in alleviating cognitive dysfunction and to explore its effects on brain activity in spontaneously hypertensive rats (SHRs) with hyperactivity of liver-yang (Gan Yang Shang Kang, GYSK). Sixteen SHRs were randomized into treatment group and non-treatment. The SHR with GYSK was induced by gavaging aconite decoction (10mL/kg at 0.2g/mL). After the SHR models were prepared, the rats in the treatment group were administered TMGTP (10mL/kg) once a day for 14days.The rats in the non-treatment group or normal rats (control group) received an equivalent volume of saline. Morris water maze test was conducted before and after the treatment to observe cognitive function. Fluorine 18-deoxy glucose [F-18]FDG micro-PET brain imaging scans was performed after treatment. Data were analyzed with two-sample t-test (P<0. 001) using SPM2 image analysis software. Compared with the non-treatment group, the escape latency significantly decreased but the frequency of entrance into the target zone significantly increased in the treatment group. Consistent with the alteration of cognitive functions, TMGTP induced strong brain activity in the following sites: right dorsolateral nucleus and ventrolateral nucleus of thalamus, amygdala, left met thalamus, cerebellum leaflets, original crack, front cone crack, loop-shaped leaflets; but deactivation of right medial frontal gyrus, bilateral corpus callosum, hippocampus, and left dentate gyrus. TMGTP could alleviate cognitive dysfunction in SHRs with GYSK, which was possibly by inducing alteration of glucose metabolism in different brain regions with corresponding functions. Copyright © 2017. Published by Elsevier Masson SAS.
Xie, Yanying; Liu, Liangsheng; Xie, Jiajiang
2016-12-12
To compare the differences in the clinical efficacy on depression differentiated as yang deficiency between the combined therapy of ginger-isolated moxibustion and escitalopram and the simple application escitalopram. Eighty patients of depression differentiated as yang deficiency were randomized into an observation group and a control group, 40 cases in each one. In the control group, escitalopram was prescribed for oral administration, 10 mg a day, after each breakfast. In the observation group, on the basis of the treatment as the control group, the ginger-isolated moxibustion was supplemented at Dazhui (GV 14) and bilateral back- shu points of five zang organs[Xinshu (BL 15), Ganshu (BL 18), Pishu (BL 20), Feishu (BL 13) and Shenshu (BL 23)]. Moxibustion was used 5 times a week. Twenty times of moxibustion were taken as one session and totally 3 sessions were required (totally 84 days). After 3 sessions of treatment, the concentration of serum 5-hydroxytryptamine (5-HT) before and after treatment and clinical efficacy were observed in the two groups. After 3 sessions of treatment, escitalopram was taken continuously, 10 mg a day for 9 months in the two groups and the recurrent rate was observed in a half year after discontinuity of medication in the two groups. The total effective rate was 97.5% (39/40) in the observation group and was 92.5% (37/40) in the control group. The total effective rate was similar between the two groups (both P >0.05). The curative and remarkably effective rate was 82.5% (33/40) in the observation group, better than 62.5% (25/40) in the control group ( P <0.05). The serum 5-HT after treatment was increased as compared with that before treatment in the patients of the two groups (both P <0.05), but the diffe-rence was not significant statistically between the two groups ( P >0.05). The recurrent rate of depression was 7.7% (3/39) in the observation group, lower than 27.0% (10/37) in the control group ( P <0.05). The combined therapy of
The "yin and yang" of the adrenal and gonadal systems in elite military men.
Taylor, Marcus K; Hernández, Lisa M; Kviatkovsky, Shiloah A; Schoenherr, Matthew R; Stone, Michael S; Sargent, Paul
2017-05-01
We recently established daily, free-living profiles of the adrenal hormone cortisol, the (primarily adrenal) anabolic precursor dehydroepiandrosterone (DHEA) and the (primarily gonadal) anabolic hormone testosterone in elite military men. A prevailing view is that adrenal and gonadal systems reciprocally modulate each other; however, recent paradigm shifts prompted the characterization of these systems as parallel, cooperative processes (i.e. the "positive coupling" hypothesis). In this study, we tested the positive coupling hypothesis in 57 elite military men by evaluating associations between adrenal and gonadal biomarkers across the day. Salivary DHEA was moderately and positively coupled with salivary cortisol, as was salivary testosterone. Anabolic processes (i.e. salivary DHEA and testosterone) were also positively and reliably coupled across the day. In multivariate models, salivary DHEA and cortisol combined to account for substantial variance in salivary testosterone concentrations across the day, but this was driven almost exclusively by DHEA. This may reflect choreographed adrenal release of DHEA with testicular and/or adrenal release of testosterone, systemic conversion of DHEA to testosterone, or both. DHEA and testosterone modestly and less robustly predicted cortisol concentrations; this was confined to the morning, and testosterone was the primary predictor. Altogether, top-down co-activation of adrenal and gonadal hormone secretion may complement bottom-up counter-regulatory functions to foster anabolic balance and neuronal survival; hence, the "yin and yang" of adrenal and gonadal systems. This may be an adaptive process that is amplified by stress, competition, and/or dominance hierarchy.
VizieR Online Data Catalog: Lyα profile in 43 Green Pea galaxies (Yang+, 2017)
NASA Astrophysics Data System (ADS)
Yang, H.; Malhotra, S.; Gronke, M.; Rhoads, J. E.; Leitherer, C.; Wofford, A.; Jiang, T.; Dijkstra, M.; Tilvi, V.; Wang, J.
2018-03-01
In SDSS DR7, a sample of 251 Green Peas was observed as serendipitous spectroscopic targets (Cardamone+ 2009MNRAS.399.1191C). A subset of 66 Green Peas have sufficient signal-to-noise ratio (S/N) in both continuum and emission lines (Hα, Hβ, and [OIII]λ5007) to study galactic properties. In Paper I (Yang+ 2016ApJ...820..130Y), we matched these 66 Green Peas with the COS archive and studied Lyα escape in a sample of 12 Green Peas with COS UV spectra. To address the bias and expand the sample size, we took the Lyα spectra of 20 additional Green Peas (PI S. Malhotra, GO 14201). We also supplement this sample with 11 additional Green Peas from published literature. In total, we have 43 Green Peas from six HST programs -- 20 galaxies from GO 14201 (PI S. Malhotra), 9 galaxies from GO 12928 (PI A. Henry; Henry+ 2015ApJ...809...19H), 7 galaxies from GO 11727 and GO 13017 (PI T. Heckman; Heckman+ 2011ApJ...730....5H ; Alexandroff+ 2015ApJ...810..104A), 2 galaxies from GO 13293 (PI A. Jaskot; Jaskot & Oey 2014ApJ...791L..19J), and 5 galaxies from GO 13744 (PI T. Thuan; Izotov+ 2016MNRAS.461.3683I). (4 data files).
NASA Astrophysics Data System (ADS)
Silva, P. J.; Oliveira, O.
2016-06-01
The correlations between the modulus of the Polyakov loop, its phase θ , and the Landau gauge gluon propagator at finite temperature are investigated in connection with the center symmetry for pure Yang-Mills SU(3) theory. In the deconfined phase, where the center symmetry is spontaneously broken, the phase of the Polyakov loop per configuration is close to θ =0 , ±2 π /3 . We find that the gluon propagator form factors associated with θ ≈0 differ quantitatively and qualitatively from those associated to θ ≈±2 π /3 . This difference between the form factors is a property of the deconfined phase and a sign of the spontaneous breaking of the center symmetry. Furthermore, given that this difference vanishes in the confined phase, it can be used as an order parameter associated to the deconfinement transition. For simulations near the critical temperature Tc, the difference between the propagators associated to θ ≈0 and θ ≈±2 π /3 allows one to classify the configurations as belonging to the confined or deconfined phase. This establishes a selection procedure which has a measurable impact on the gluon form factors. Our results also show that the absence of the selection procedure can be erroneously interpreted as lattice artifacts.
NASA Astrophysics Data System (ADS)
Tang, Panpan; Chen, Fulong; Jiang, Aihui; Zhou, Wei; Wang, Hongchao; Leucci, Giovanni; de Giorgi, Lara; Sileo, Maria; Luo, Rupeng; Lasaponara, Rosa; Masini, Nicola
2018-04-01
This study presents the potential of multi-frequency electromagnetic induction (EMI) in archaeology. EMI is currently less employed for archaeological prospection with respect to other geophysical techniques. It is capable of identifying shallow subsurface relics by simultaneously measuring the apparent electrical conductivity (ECa) and apparent magnetic susceptibility (MSa). Moreover, frequency sounding is able to quantify the depths and vertical shapes of buried structures. In this study, EMI surveys with five frequencies were performed at two heritage sites with different geological conditions: Han Hangu Pass characterized by cinnamon soil and Xishan Yang by sandy loams. In the first site, high ECa values were observed with variations in depth correlated to archaeological remains. Moreover, electromagnetic anomalies related to an ancient road and five kiln caves were identified. In the second site, an ancient tomb, indicating extremely low ECa and high MSa, was discovered. Its electromagnetic properties are attributed to the cavity and ferroferric oxides.
NASA Astrophysics Data System (ADS)
Baxter, J. Erik; Winstanley, Elizabeth
2016-02-01
We investigate the stability of spherically symmetric, purely magnetic, soliton and black hole solutions of four-dimensional 𝔰𝔲(N) Einstein-Yang-Mills theory with a negative cosmological constant Λ. These solutions are described by N - 1 magnetic gauge field functions ωj. We consider linear, spherically symmetric, perturbations of these solutions. The perturbations decouple into two sectors, known as the sphaleronic and gravitational sectors. For any N, there are no instabilities in the sphaleronic sector if all the magnetic gauge field functions ωj have no zeros and satisfy a set of N - 1 inequalities. In the gravitational sector, we prove that there are solutions which have no instabilities in a neighbourhood of stable embedded 𝔰𝔲(2) solutions, provided the magnitude of the cosmological constant |" separators=" Λ | is sufficiently large.
The Merger Rate of Binary White Dwarfs in the Galactic Disk
NASA Astrophysics Data System (ADS)
Badenes, Carles; Maoz, Dan
2012-04-01
We use multi-epoch spectroscopy of ~4000 white dwarfs in the Sloan Digital Sky Survey to constrain the properties of the Galactic population of binary white dwarf systems and calculate their merger rate. With a Monte Carlo code, we model the distribution of ΔRVmax, the maximum radial velocity shift between exposures of the same star, as a function of the binary fraction within 0.05 AU, f bin, and the power-law index in the separation distribution at the end of the common-envelope phase, α. Although there is some degeneracy between f bin and α, the 15 high-ΔRVmax systems that we find constrain the combination of these parameters, which determines a white dwarf merger rate per unit stellar mass of 1.4+3.4 -1.0 × 10-13 yr-1 M -1 ⊙ (1σ limits). This is remarkably similar to the measured rate of Type Ia supernovae (SNe Ia) per unit stellar mass in Milky-Way-like Sbc galaxies. The rate of super-Chandrasekhar mergers is only 1.0+1.6 -0.6 × 10-14 yr-1 M -1 ⊙. We conclude that there are not enough close binary white dwarf systems to reproduce the observed SN Ia rate in the "classic" double degenerate super-Chandrasekhar scenario. On the other hand, if sub-Chandrasekhar mergers can lead to SNe Ia, as has been recently suggested by some studies, they could make a major contribution to the overall SN Ia rate. Although unlikely, we cannot rule out contamination of our sample by M-dwarf binaries or non-Gaussian errors. These issues will be clarified in the near future by completing the follow-up of all 15 high-ΔRVmax systems.
Accreting CO material onto ONe white dwarfs towards accretion-induced collapse
NASA Astrophysics Data System (ADS)
Wu, Cheng-Yuan; Wang, Bo
2018-03-01
The final outcomes of accreting ONe white dwarfs (ONe WDs) have been studied for several decades, but there are still some issues that are not resolved. Recently, some studies suggested that the deflagration of oxygen would occur for accreting ONe WDs with Chandrasekhar masses. In this paper, we aim to investigate whether ONe WDs can experience accretion-induced collapse (AIC) or explosions when their masses approach the Chandrasekhar limit. Employing the stellar evolution code Modules for Experiments in Stellar Astrophysics (MESA), we simulate the long-term evolution of ONe WDs with accreting CO material. The ONe WDs undergo weak multicycle carbon flashes during the mass-accretion process, leading to mass increase of the WDs. We found that different initial WD masses and mass-accretion rates influence the evolution of central density and temperature. However, the central temperature cannot reach the explosive oxygen ignition temperature due to neutrino cooling. This work implies that the final outcome of accreting ONe WDs is electron-capture induced collapse rather than thermonuclear explosion.
Physical interpretation of Jeans instability in quantum plasmas
DOE Office of Scientific and Technical Information (OSTI.GOV)
Akbari-Moghanjoughi, M.; International Centre for Advanced Studies in Physical Sciences and Institute for Theoretical Physics, Ruhr University Bochum, D-44780 Bochum
2014-08-15
In this paper, we use the quantum hydrodynamics and its hydrostatic limit to investigate the newly posed problem of Jeans instability in quantum plasmas from a different point of view in connection with the well-known Chandrasekhar mass-limit on highly collapsed degenerate stellar configurations. It is shown that the hydrodynamic stability of a spherically symmetric uniform quantum plasma with a given fixed mass is achieved by increase in its mass-density or decrease in the radius under the action of gravity. It is also remarked that for masses beyond the limiting Jeans-mass, the plasma becomes completely unstable and the gravitational collapse wouldmore » proceed forever. This limiting mass is found to depend strongly on the composition of the quantum plasma and the atomic-number of the constituent ions, where it is observed that heavier elements rather destabilize the quantum plasma hydrodynamically. It is also shown that the Chandrasekhar mass-limit for white dwarf stars can be directly obtained from the hydrostatic limit of our model.« less
A 16 Yin Yang gene expression ratio signature for ER+/node- breast cancer.
Xu, Wayne; Jia, Gaofeng; Cai, Nianguang; Huang, Shujun; Davie, James R; Pitz, Marshall; Banerji, Shantanu; Murphy, Leigh
2017-03-15
Breast cancer is one of the leading causes of cancer death in women. It is a complex and heterogeneous disease with different clinical outcomes. Stratifying patients into subgroups with different outcomes could help guide clinical decision making. In this study, we used two opposing groups of genes, Yin and Yang, to develop a prognostic expression ratio signature. Using the METABRIC cohort we identified a16-gene signature capable of stratifying breast cancer patients into four risk levels with intention that low-risk patients would not undergo adjuvant systemic therapy, intermediate-low-risk patients will be treated with hormonal therapy only, and intermediate-high- and high-risk groups will be treated by chemotherapy in addition to the hormonal therapy. The 16-gene signature for four risk level stratifications of breast cancer patients has been validated using 14 independent datasets. Notably, the low-risk group (n = 51) of 205 estrogen receptor-positive and node negative (ER+/node-) patients from three different datasets who had not had any systemic adjuvant therapy had 100% 15-year disease-specific survival rate. The Concordance Index of YMR for ER+/node negative patients is close to the commercially available signatures. However, YMR showed more significance (HR = 3.7, p = 8.7e-12) in stratifying ER+/node- subgroup than OncotypeDx (HR = 2.7, p = 1.3e-7), MammaPrint (HR = 2.5, p = 5.8e-7), rorS (HR = 2.4, p = 1.4e-6), and NPI (HR = 2.6, p = 1.2e-6). YMR signature may be developed as a clinical tool to select a subgroup of low-risk ER+/node- patients who do not require any adjuvant hormonal therapy (AHT). © 2016 UICC.
[Suh Yang Park, who became a doctor as a son of a butcher].
Park, Hyoung Woo; Hong, Jung Wan
2006-12-01
Dr. Suh Yang Park was born in 1885 as a son of a butcher, which was the lowest class at that time in Korea. However, contact with western missionaries, including Dr. 0. R. Avison, provided him with an understanding of western civilization. After entering Chejungwon Medical School in 1900, Dr. Park learned basic sciences, basic medical sciences like anatomy and physiology, and other Western medical specialties such as internal medicine and surgery. He graduated from medical school in 1908 and received Government Certificate from Home Office, the first in Korea in this field, which granted the right to practice medicine. His certificate number was 4th overall. As both a doctor and a talented musician, Dr. Park actively participated in the social enlightenment movement. He was quite progressive in his time, having surpassed the social limitations as a son of a butcher, as well as actively propagating his knowledge of Western civilization onto others. After graduation, he had served as a professor at the school he graduated from, until he went into exile in Manchuria in 1917 due to the annexation of Korea by Japan in 1910. There, he opened a hospital and provided medical treatment for Koreans. He also established a school for young Koreans, inspiring them with a sense of nationalism. Also, Dr. Park was an active member of various Independence Movement Organizations in Manchuria. Then in 1932, at the time when Japan took control of Manchuria, his school was closed down. As a result, Dr. Park couldn't help but stop his anti-Japanese activities. In 1936, he returned to his homeland and passed away in 1940, just five years before the liberation of Korea from Japanese occupation.
Jeans, Sir James Hopwood (1877-1946)
NASA Astrophysics Data System (ADS)
Murdin, P.
2000-11-01
Astrophysicist, born in Ormskirk, Lancashire, England, worked at Cambridge, Princeton and Mount Wilson Observatory, and retired early to devote himself to research. Like CHANDRASEKHAR, Jeans worked on physical problems such as thermodynamics, applying the physics to astronomy, and writing lucid accounts of the whole field in books such as The Dynamical Theory of Gases (1904), Theoretical Mechanic...
Ke, Zheng-hua; Long, Sheng-hua
2014-09-01
To compare the clinical efficacy differences between medicinal vesiculation combined with quick cupping at Shenque (CV 8) and regular medication for allergic rhinitis with syndrome of yang deficiency. Eighty-two cases were randomly divided into an observation group (42 cases) and a control group (40 cases). The observation group was treated with medicinal vesiculation combined with quick cupping at Shenque (CV 8). The medicinal vesiculation was applied at Feishu (BL 13), Gaohuang (BL 43), Fengmen (BL 12), Mingmen (GV 4) on the dog days in the summer, one treatment on the 1st dog-day, 2nd dog-day and last dog-day respectively with an interval of 10 days between two treatments. Three treatments were taken as one course, and totally one course was given. The quick cupping was applied at Shenque (CV 8), once a day, ten treatments were taken as one course, and totally three courses was given. The control group was treated with oral administration of loratadine and nasal spray of budesonide. The loratadine was given 10 mg per time, once a day for continuous 14 days; budesonide was given once a day, ten treatments were taken as one course, and totally three courses was given. The clinical efficacy in two groups after treatment was observed, and the contents of immune globulin E (IgE), interleukin-4 (IL-4), interleukin-5 (IL-5) and tumor necrosis factor-α (TNF-α) in peripheral serum were measured before and after the treatments. Of all the 82 patients, 79 cases completed the treatment, and 1 patient in the observation group and 2 patients in the control group dropped out. The effective rate was 87.8% (36/41) in the observation group, which was superior to 78.9% (30/38) in the control group (P<0.05). After treatment, both groups effectively reduced the contents of IgE, IL-4, IL-5 and TNF-α, and the observation group had superior effect on reducing IgE and IL-4 to the control group (P<0.05). The medicinal vesiculation combined with quick cupping at Shenque (CV 8) have
Ma, Guoqing; Ye, Ting; Sun, Zhongren
2018-03-12
To compare the clinical efficacy differences between warming acupuncture and conventional acupuncture for diabetic peripheral neuropathy (DPN) with syndrome of yang deficiency and cold coagulation, obstruction of collaterals and blood stasis. A total of 64 patients were randomly divided into a warming acupuncture group and a conventional acupuncture group, 32 cases in each one. Based on basic treatment of blood glucose regulation, warming acupuncture was applied at Pishu (BL 20), Shenshu (BL 23), Guanyuanshu (BL 26), Zusanli (ST 36), Chongyang (ST 42), Quchi (LI 11) and Hegu (LI 4) in the warming acupuncture group, while acupuncture was applied at the identical acupoints in the conventional acupuncture group. Both the treatments were given once a day with an interval of one day every six days; totally the treatment was given for 4 weeks. The TCM symptom score, Toronto clinical scoring system (TCSS) and nerve conduction velocity (NCV) before and after treatment were compared in the two groups. After treatment, the TCM symptom scores in the two groups were significantly reduced (both P <0.01); the improvement of TCM symptom in the warming acupuncture group was superior to that in the conventional acupuncture group ( P <0.05). After treatment, the TCSS scores in the two groups were significantly reduced (both P <0.01); the TCSS score in the warming acupuncture group was significantly lower than that in the conventional acupuncture group ( P <0.05). After treatment, the NCV of motor nerve of tibial nerve and nervus peroneus communis, as well as sensory nerve of tibial nerve and sural nerve was improved in the warming acupuncture group (all P <0.05), while only the NCV of motor nerve and sensory nerve of tibial nerve was improved in the conventional acupuncture group (both P <0.05); there were no significant difference between the two groups (all P >0.05). Warming acupuncture and conventional acupuncture could both increase TCM symptom score, improve NCV in patients of
DOE Office of Scientific and Technical Information (OSTI.GOV)
Uchino, Shun; Kobayashi, Michikazu; Ueda, Masahito
2010-06-15
We develop Bogoliubov theory of spin-1 and spin-2 Bose-Einstein condensates (BECs) in the presence of a quadratic Zeeman effect, and derive the Lee-Huang-Yang (LHY) corrections to the ground-state energy, pressure, sound velocity, and quantum depletion. We investigate all the phases of spin-1 and spin-2 BECs that can be realized experimentally. We also examine the stability of each phase against quantum fluctuations and the quadratic Zeeman effect. Furthermore, we discuss a relationship between the number of symmetry generators that are spontaneously broken and that of Nambu-Goldstone (NG) modes. It is found that in the spin-2 nematic phase there are special Bogoliubovmore » modes that have gapless linear dispersion relations but do not belong to the NG modes.« less
Single Degenerate Models for Type Ia Supernovae: Progenitor's Evolution and Nucleosynthesis Yields
NASA Astrophysics Data System (ADS)
Nomoto, Ken'ichi; Leung, Shing-Chi
2018-06-01
We review how the single degenerate models for Type Ia supernovae (SNe Ia) works. In the binary star system of a white dwarf (WD) and its non-degenerate companion star, the WD accretes either hydrogen-rich matter or helium and undergoes hydrogen and helium shell-burning. We summarize how the stability and non-linear behavior of such shell-burning depend on the accretion rate and the WD mass and how the WD blows strong wind. We identify the following evolutionary routes for the accreting WD to trigger a thermonuclear explosion. Typically, the accretion rate is quite high in the early stage and gradually decreases as a result of mass transfer. With decreasing rate, the WD evolves as follows: (1) At a rapid accretion phase, the WD increase its mass by stable H burning and blows a strong wind to keep its moderate radius. The wind is strong enough to strip a part of the companion star's envelope to control the accretion rate and forms circumstellar matter (CSM). If the WD explodes within CSM, it is observed as an "SN Ia-CSM". (X-rays emitted by the WD are absorbed by CSM.) (2) If the WD continues to accrete at a lower rate, the wind stops and an SN Ia is triggered under steady-stable H shell-burning, which is observed as a super-soft X-ray source: "SN Ia-SSXS". (3) If the accretion continues at a still lower rate, H shell-burning becomes unstable and many flashes recur. The WD undergoes recurrent nova (RN) whose mass ejection is smaller than the accreted matter. Then the WD evolves to an "SN Ia-RN". (4) If the companion is a He star (or a He WD), the accretion of He can trigger He and C double detonations at the sub-Chandrasekhar mass or the WD grows to the Chandrasekhar mass while producing a He-wind: "SN Ia-He CSM". (5) If the accreting WD rotates quite rapidly, the WD mass can exceed the Chandrasekhar mass of the spherical WD, which delays the trigger of an SN Ia. After angular momentum is lost from the WD, the (super-Chandra) WD contracts to become a delayed SN Ia
Xia, Depeng; Chen, Peifang; Du, Peixue; Ding, Lijun; Liu, Anli
2017-08-12
To observe the efficacy differences between acupoint catgut embedding combined with ginger-partitioned moxibustion and regular acupuncture on chronic fatigue syndrome (CFS) of spleen-kidney yang deficiency syndrome, and to explore its effects on T lymphocyte subsets and activity of NK cell. A total of 60 patients with CFS of spleen-kidney yang deficiency syndrome were randomly divided into a catgut embedding combined with ginger-partitioned moxibustion (CECGP) group and a regular acupuncture group, 30 cases in each one. The patients in the CECGP group were treated with acupoint catgut embedding combined with ginger-partitioned moxibustion; the acupoint catgut embedding was applied at Guanyuan (CV 4), Shenshu (BL 23), Pishu (BL 20), Zusanli (ST 36), Qihai (CV 6), once a week, while the ginger-partitioned moxibustion was applied at Guanyuan (CV 4), Qihai (CV 6) and Zusanli (ST 36), once every three days for consecutive one month. The patients in the regular acupuncture group were treated with regular acupuncture at Guanyuan (CV 4), Shenshu (BL 23), Pishu (BL 20), Zusanli (ST 36), Qihai (CV 6), once a day, 6 treatments per week (one day for rest) for consecutive one month. The clinical symptom scores, fatigue scale-14 (FS-14), fatigue assessment instrument (FAI), laboratory test results and total effective rate were compared between the two groups before and after treatment. (1) After treatment, the clinical symptom scores, FS-14 and FAI were reduced in the two groups (all P <0.05); after treatment, the clinical symptom scores, FS-14 and FAI in the CECGP group were significantly lower than those in the regular acupuncture group (all P <0.05). (2) After treatment, the CD 4 + /CD 8 + , natural killer cell% (NK%), CD 3 + %, CD% were all increased in the two groups (all +4 P <0.05); the CD 4 + /CD 8 + , CD 3 + %, CD% in the CECGP group were significantly higher than those in the regular acupuncture group (all P <0.05). (3) After treatment, the total effective rate was 96
NASA Astrophysics Data System (ADS)
Baxter, J. Erik
2016-10-01
We investigate the existence of black hole and soliton solutions to four dimensional, anti-de Sitter (adS), Einstein-Yang-Mills theories with general semisimple connected and simply connected gauge groups, concentrating on the so-called regular case. We here generalise results for the asymptotically flat case, and compare our system with similar results from the well-researched adS {mathfrak {su}}(N) system. We find the analysis differs from the asymptotically flat case in some important ways: the biggest difference is that for Λ <0, solutions are much less constrained as r→ infty , making it possible to prove the existence of global solutions to the field equations in some neighbourhood of existing trivial solutions, and in the limit of |Λ |→ infty . In particular, we can identify non-trivial solutions where the gauge field functions have no zeroes, which in the {mathfrak {su}}(N) case proved important to stability.
Dark Matter Ignition of Type Ia Supernovae.
Bramante, Joseph
2015-10-02
Recent studies of low redshift type Ia supernovae (SN Ia) indicate that half explode from less than Chandrasekhar mass white dwarfs, implying ignition must proceed from something besides the canonical criticality of Chandrasekhar mass SN Ia progenitors. We show that 1-100 PeV mass asymmetric dark matter, with imminently detectable nucleon scattering interactions, can accumulate to the point of self-gravitation in a white dwarf and collapse, shedding gravitational potential energy by scattering off nuclei, thereby heating the white dwarf and igniting the flame front that precedes SN Ia. We combine data on SN Ia masses with data on the ages of SN Ia-adjacent stars. This combination reveals a 2.8σ inverse correlation between SN Ia masses and ignition ages, which could result from increased capture of dark matter in 1.4 vs 1.1 solar mass white dwarfs. Future studies of SN Ia in galactic centers will provide additional tests of dark-matter-induced type Ia ignition. Remarkably, both bosonic and fermionic SN Ia-igniting dark matter also resolve the missing pulsar problem by forming black holes in ≳10 Myr old pulsars at the center of the Milky Way.
Analysis of Chinese Power: The Economic Base and Potential for Military and Political Power
1966-04-08
projection .... 23 Birth control . 27 4. AGRICULTURE 29 Arable land 30 Production 34 Fertilizer - irrigation - tractors ...... 36 Food grain...32chandrasekhar, op. cit., p. 151. 26 I BIRTH CONTROL A discussion of Communist China’s tremendous population and the threat of a billion...people around 1980 would be incomplete with- out a word about birth control measures. The traditional official Communist line with respect to
NASA Astrophysics Data System (ADS)
Tanikawa, Ataru; Nakasato, Naohito; Sato, Yushi; Nomoto, Ken'ichi; Maeda, Keiichi; Hachisu, Izumi
2015-07-01
We perform smoothed particle hydrodynamics simulations for merging binary carbon-oxygen (CO) WDs with masses of 1.1 and 1.0 {M}⊙ , until the merger remnant reaches a dynamically steady state. Using these results, we assess whether the binary could induce a thermonuclear explosion, and whether the explosion could be observed as a type Ia supernova (SN Ia). We investigate three explosion mechanisms: a helium-ignition following the dynamical merger (“helium-ignited violent merger model”), a carbon-ignition (“carbon-ignited violent merger model”), and an explosion following the formation of the Chandrasekhar mass WD (“Chandrasekhar mass model”). An explosion of the helium-ignited violent merger model is possible, while we predict that the resulting SN ejecta are highly asymmetric since its companion star is fully intact at the time of the explosion. The carbon-ignited violent merger model can also lead to an explosion. However, the envelope of the exploding WD spreads out to ˜ 0.1 {R}⊙ ; it is much larger than that inferred for SN 2011fe (\\lt 0.1 {R}⊙ ) while much smaller than that for SN 2014J (˜ 1 {R}⊙ ). For the particular combination of the WD masses studied in this work, the Chandrasekhar mass model does not successfully lead to an SN Ia explosion. Besides these assessments, we investigate the evolution of unbound materials ejected through the merging process (“merger ejecta”), assuming a case where the SN Ia explosion is not triggered by the helium- or carbon-ignition during the merger. The merger ejecta interact with the surrounding interstellar medium and form a shell. The shell has a bolometric luminosity of more than 2× {10}35 {erg} {{{s}}}-1, lasting for ˜ 2× {10}4 years. If this is the case, the Milky Way should harbor about 10 such shells at any given time. The detection of the shell(s) can therefore rule out the helium-ignited and carbon-ignited violent merger models as major paths to SN Ia explosions.
Xu, Cui-Ping; Zhu, Qing-Jun; Song, Jie; Li, Zhen; Zhang, Dan
2013-02-01
To explore the effects of Jingui Shenqi Pill (JSP) on the testis telomerase activity in mice of Shen-yang deficiency syndrome (SYDS). The SYDS model was prepared in 30 mice by over-fatigue and sexual overstrain. They were randomly divided into the model group and the JSP group, 15 in each group. Another 15 normal male mice were selected as the normal group. Mice in the normal group were fed routinely, with distilled water administered intragastrically at the daily dose of 0.1 mL/10 g. Mice in the model group were also administered intragastrically with distilled water at the daily dose of 0.1 mL/10 g while modeling establishment. Mice in the treatment group were administered intragastrically with JSP suspension at 0.1 mL/10 g (the concentration was 0.241 g/mL). The intervention lasted for 4 weeks. Four weeks later, the testis telomerase activity was detected in the three groups by ELISA. The SYDS model was replicated successfully by over-fatigue and sexual overstrain. JSP could improve the signs of mice of SYDS. Compared with the normal group, the activity of testis telomerase decreased in the model group (P < 0.01). Compared with the model group, the testis telomerase activity markedly increased in the treatment group (P < 0.01). The testis telomerase activity in mice of SYDS caused by over-fatigue and sexual overstrain obviously decreased, when compared with that in mice of the normal group. JSP could recover its activity.
Daraiseh, Susan I; Kassardjian, Ari; Alexander, Karen E; Rizkallah, Raed; Hurt, Myra M
2018-05-25
Yin Yang 1 (YY1) is a multifunctional transcription factor that can activate or repress transcription depending on the promotor and/or the co-factors recruited. YY1 is phosphorylated in various signaling pathways and is critical for different biological functions including embryogenesis, apoptosis, proliferation, cell-cycle regulation and tumorigenesis. Here we report that YY1 is a substrate for c-Abl kinase phosphorylation at conserved residue Y254 in the spacer region. Pharmacological inhibition of c-Abl kinase by imatinib, nilotinib and GZD824, knock-down of c-Abl using siRNA, and the use of c-Abl kinase-dead drastically reduces tyrosine phosphorylation of YY1. Both radioactive and non-radioactive in vitro kinase assays, as well as co-immunoprecipitation in different cell lines, show that the target of c-Abl phosphorylation is tyrosine residue 254. c-Abl phosphorylation has little effect on YY1 DNA binding ability or cellular localization in asynchronous cells. However, functional studies reveal that c-Abl mediated phosphorylation of YY1 regulates YY1's transcriptional ability in vivo. In conclusion, we demonstrate the novel role of c-Abl kinase in regulation of YY1's transcriptional activity, linking YY1 regulation with c-Abl tyrosine kinase signaling pathways. Copyright © 2018. Published by Elsevier B.V.
Ellis, Peter D; Martin, Karen M; Rickman, Colin; Metcalfe, James C; Kemp, Paul R
2002-01-01
Recent evidence has implicated CC(A/T(richG))GG (CArG) boxes, binding sites for serum response factor (SRF), in the regulation of expression of a number of genes in response to changes in the actin cytoskeleton. In many cases, the activity of SRF at CArG boxes is modulated by transcription factors binding to overlapping (e.g. Yin Yang 1, YY1) or adjacent (e.g. ets) binding sites. However, the mechanisms by which SRF activity is regulated by the cytoskeleton have not been determined. To investigate these mechanisms, we screened for cells that did or did not increase the activity of a fragment of the promoter for a smooth-muscle (SM)-specific gene SM22alpha, in response to changes in actin cytoskeletal polymerization induced by LIM kinase. These experiments showed that vascular SM cells (VSMCs) and C2C12 cells increased the activity of promoters containing at least one of the SM22alpha CArG boxes (CArG near) in response to LIM kinase, whereas P19 cells did not. Bandshift assays using a probe to CArG near showed that P19 cells lacked detectable YY1 DNA binding to the CArG box in contrast with the other two cell types. Expression of YY1 in P19 cells inhibited SM22alpha promoter activity and conferred responsiveness to LIM kinase. Mutation of the CArG box to inhibit YY1 or SRF binding indicated that both factors were required for the LIM kinase response in VSMCs and C2C12 cells. The data indicate that changes in the actin cytoskeletal organization modify SRF activity at CArG boxes by modulating YY1-dependent inhibition. PMID:12023898
Introduction to the Theory of Atmospheric Radiative Transfer
NASA Technical Reports Server (NTRS)
Buglia, J. J.
1986-01-01
The fundamental physical and mathematical principles governing the transmission of radiation through the atmosphere are presented, with emphasis on the scattering of visible and near-IR radiation. The classical two-stream, thin-atmosphere, and Eddington approximations, along with some of their offspring, are developed in detail, along with the discrete ordinates method of Chandrasekhar. The adding and doubling methods are discussed from basic principles, and references for further reading are suggested.
Pinching Solutions of Slender Cylindrical Jets
1993-06-01
NASA Langley Research Center, Hampton, VA 23681.2This research was supported in part by Fondo Nacional de Desarrollo Cientifico y Tecnologico (FONDE...concentrate on inviscid irrotational flows of liquid jets. A review article has been written by Bogy [2]. Of relevance is also the work of Chandrasekhar...equations become elliptic and allow the possibility of admissible pinching solutions described in this article . It is interesting to find that for jets
NASA Technical Reports Server (NTRS)
Fricke, C. L.
1975-01-01
A solution to the problem of reflection from a semi-infinite atmosphere is presented, based upon Chandrasekhar's H-function method for linearly anisotropic phase functions. A modification to the Gauss quadrature formula which gives about the same accuracy with 10 points as the conventional Gauss quadrature does with 100 points was developed. A computer program achieving this solution is described and results are presented for several illustrative cases.
Affar, El Bachir; Gay, Frédérique; Shi, Yujiang; Liu, Huifei; Huarte, Maite; Wu, Su; Collins, Tucker; Li, En; Shi, Yang
2006-01-01
Constitutive ablation of the Yin Yang 1 (YY1) transcription factor in mice results in peri-implantation lethality. In this study, we used homologous recombination to generate knockout mice carrying yy1 alleles expressing various amounts of YY1. Phenotypic analysis of yy1 mutant embryos expressing ∼75%, ∼50%, and ∼25% of the normal complement of YY1 identified a dosage-dependent requirement for YY1 during late embryogenesis. Indeed, reduction of YY1 levels impairs embryonic growth and viability in a dose-dependent manner. Analysis of the corresponding mouse embryonic fibroblast cells also revealed a tight correlation between YY1 dosage and cell proliferation, with a complete ablation of YY1 inducing cytokinesis failure and cell cycle arrest. Consistently, RNA interference-mediated inhibition of YY1 in HeLa cells prevents cytokinesis, causes proliferative arrest, and increases cellular sensitivity to various apoptotic agents. Genome-wide expression profiling identified a plethora of YY1 target genes that have been implicated in cell growth, proliferation, cytokinesis, apoptosis, development, and differentiation, suggesting that YY1 coordinates multiple essential biological processes through a complex transcriptional network. These data not only shed new light on the molecular basis for YY1 developmental roles and cellular functions, but also provide insight into the general mechanisms controlling eukaryotic cell proliferation, apoptosis, and differentiation. PMID:16611997
A novel role of Yin-Yang-1 in pulmonary tuberculosis through the regulation of the chemokine CCL4.
Rangel-Santiago, Jesus F; Baay-Guzman, Guillermina J; Duran-Padilla, Marco A; Lopez-Bochm, Karla A; Garcia-Romero, Beatriz L; Hernandez-Cueto, Daniel D; Pantoja-Escobar, Gerardo; Vega, Mario I; Hernandez-Pando, Rogelio; Huerta-Yepez, Sara
2016-01-01
Mycobacterium tuberculosis (M. tb) is the etiological agent of pulmonary tuberculosis (TB); this disease remains a worldwide health problem. Yin-Yang-1 (YY1) plays a major role in the maintenance and progression of some pulmonary diseases, including pulmonary fibrosis. However, the role of YY1 in TB remains unknown. The aim of this study was to elucidate the role of YY1 in the regulation of CCL4 and its implication in TB. We determined whether YY1 regulates CCL4 using reporter plasmids, ChIP and siRNA assays. Immunohistochemistry and digital pathology were used to measure the expression of YY1 and CCL4 in a mouse model of TB. A retrospective comparison of patients with TB and control subjects was used to measure the expression of YY1 and CCL4 using tissue microarrays. Our results showed that YY1 regulates the transcription of CCL4; moreover, YY1, CCL4 and TGF-β were overexpressed in the lung tissues of mice with TB during the late stages of the disease and the tissues of TB patients. The expression of CCL4 and TGF-β correlated with YY1 expression. In conclusion, YY1 regulates CCL4 transcription; moreover, YY1 is overexpressed in experimental and human TB and is positively correlated with CCL4 and TGF-β expression. Therefore, treatments that decrease YY1 expression may be a new therapeutic strategy against TB. Copyright © 2015 Elsevier Ltd. All rights reserved.
A metric space for Type Ia supernova spectra: a new method to assess explosion scenarios
NASA Astrophysics Data System (ADS)
Sasdelli, Michele; Hillebrandt, W.; Kromer, M.; Ishida, E. E. O.; Röpke, F. K.; Sim, S. A.; Pakmor, R.; Seitenzahl, I. R.; Fink, M.
2017-04-01
Over the past years, Type Ia supernovae (SNe Ia) have become a major tool to determine the expansion history of the Universe, and considerable attention has been given to, both, observations and models of these events. However, until now, their progenitors are not known. The observed diversity of light curves and spectra seems to point at different progenitor channels and explosion mechanisms. Here, we present a new way to compare model predictions with observations in a systematic way. Our method is based on the construction of a metric space for SN Ia spectra by means of linear principal component analysis, taking care of missing and/or noisy data, and making use of partial least-squares regression to find correlations between spectral properties and photometric data. We investigate realizations of the three major classes of explosion models that are presently discussed: delayed-detonation Chandrasekhar-mass explosions, sub-Chandrasekhar-mass detonations and double-degenerate mergers, and compare them with data. We show that in the principal component space, all scenarios have observed counterparts, supporting the idea that different progenitors are likely. However, all classes of models face problems in reproducing the observed correlations between spectral properties and light curves and colours. Possible reasons are briefly discussed.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Roche, Ph., E-mail: philippe.roche@univ-montp2.fr
We recall the relation between zeta function representation of groups and two-dimensional topological Yang-Mills theory through Mednikh formula. We prove various generalisations of Mednikh formulas and define generalization of zeta function representations of groups. We compute some of these functions in the case of the finite group GL(2, #Mathematical Double-Struck Capital F#{sub q}) and PGL(2, #Mathematical Double-Struck Capital F#{sub q}). We recall the table characters of these groups for any q, compute the Frobenius-Schur indicator of their irreducible representations, and give the explicit structure of their fusion rings.
Tsunami Elevation Predictions for American Samoa.
1980-09-01
tide gauge of Pago Pago after the earthquake of May 13, 1953 in Costa Rica . (Microfische Collec- tion of Tsunami Mareograms 1952-1975) July 13, 1952...34 Engineering Geology Case Histories, Geological Society of America, No. 8. Chandrasekhar, S. 1943. Reviews of Modern Physics, 15:1-89. Chen, H. S., and...Scientific abstracts and indexes relevant to earthquakes, tsunamis, and geology were also reviewed. Since there are no cumulative indexes available in most
Viscous Rayleigh-Taylor instability in spherical geometry
DOE Office of Scientific and Technical Information (OSTI.GOV)
Mikaelian, Karnig O.
We consider viscous fluids in spherical geometry, a lighter fluid supporting a heavier one. Chandrasekhar [Q. J. Mech. Appl. Math. 8, 1 (1955)] analyzed this unstable configuration providing the equations needed to find, numerically, the exact growth rates for the ensuing Rayleigh-Taylor instability. He also derived an analytic but approximate solution. We point out a weakness in his approximate dispersion relation (DR) and offer one that is to some extent improved.
Viscous Rayleigh-Taylor instability in spherical geometry
Mikaelian, Karnig O.
2016-02-08
We consider viscous fluids in spherical geometry, a lighter fluid supporting a heavier one. Chandrasekhar [Q. J. Mech. Appl. Math. 8, 1 (1955)] analyzed this unstable configuration providing the equations needed to find, numerically, the exact growth rates for the ensuing Rayleigh-Taylor instability. He also derived an analytic but approximate solution. We point out a weakness in his approximate dispersion relation (DR) and offer one that is to some extent improved.
NASA Names Premier X-Ray Observatory and Schedules Launch
NASA Astrophysics Data System (ADS)
1998-12-01
NASA's Advanced X-ray Astrophysics Facility has been renamed the Chandra X-ray Observatory in honor of the late Indian-American Nobel laureate, Subrahmanyan Chandrasekhar. The telescope is scheduled to be launched no earlier than April 8, 1999 aboard the Space Shuttle Columbia mission STS-93, commanded by astronaut Eileen Collins. Chandrasekhar, known to the world as Chandra, which means "moon" or "luminous" in Sanskrit, was a popular entry in a recent NASA contest to name the spacecraft. The contest drew more than six thousand entries from fifty states and sixty-one countries. The co-winners were a tenth grade student in Laclede, Idaho, and a high school teacher in Camarillo, CA. The Chandra X-ray Observatory Center (CXC), operated by the Smithsonian Astrophysical Observatory, will control science and flight operations of the Chandra X-ray Observatory for NASA from Cambridge, Mass. "Chandra is a highly appropriate name," said Harvey Tananbaum, Director of the CXC. "Throughout his life Chandra worked tirelessly and with great precision to further our understanding of the universe. These same qualities characterize the many individuals who have devoted much of their careers to building this premier X-ray observatory." "Chandra probably thought longer and deeper about our universe than anyone since Einstein," said Martin Rees, Great Britain's Astronomer Royal. "Chandrasekhar made fundamental contributions to the theory of black holes and other phenomena that the Chandra X-ray Observatory will study. His life and work exemplify the excellence that we can hope to achieve with this great observatory," said NASA Administrator Dan Goldin. Widely regarded as one of the foremost astrophysicists of the 20th century, Chandrasekhar won the Nobel Prize in 1983 for his theoretical studies of physical processes important to the structure and evolution of stars. He and his wife immigrated from India to the U.S. in 1935. Chandrasekhar served on the faculty of the University of
DOE Office of Scientific and Technical Information (OSTI.GOV)
Yoo, Soohaeng; Zeng, Xiao Cheng; Xantheas, Sotiris S.
2009-06-11
The melting temperature (Tm) of ice Ih was determined from constant enthalphy (NPH) Born-Oppenheimer Molecular Dynamics (BOMD) simulations to be 417±3 K for the Perdew-Burke-Ernzerhof (PBE) and 411±4 K for the Becke-Lee-Yang-Parr (BLYP) density functionals using a coexisting ice (Ih)-liquid phase at constant pressures of P = 2,500 and 10,000 bar and a density ρ = 1 g/cm3, respectively. This suggests that ambient condition simulations at ρ = 1 g/cm3 will rather describe a supercooled state that is overstructured when compared to liquid water. This work was supported by the US Department of Energy Office of Basic Energy Sciences' Chemicalmore » Sciences program. Pacific Northwest National Laboratory is operated by Battelle for the US Department of Energy.« less
Belak, Zachery R; Ovsenek, Nicholas; Eskiw, Christopher H
2018-05-23
Yin-Yang 1 (YY1) is a highly conserved transcription factor possessing RNA-binding activity. A putative YY1 homologue was previously identified in the developmental model organism Strongylocentrotus purpuratus (the purple sea urchin) by genomic sequencing. We identified a high degree of sequence similarity with YY1 homologues of vertebrate origin which shared 100% protein sequence identity over the DNA- and RNA-binding zinc-finger region with high similarity in the N-terminal transcriptional activation domain. SpYY1 demonstrated identical DNA- and RNA-binding characteristics between Xenopus laevis and S. purpuratus indicating that it maintains similar functional and biochemical properties across widely divergent deuterostome species. SpYY1 binds to the consensus YY1 DNA element, and also to U-rich RNA sequences. Although we detected SpYY1 RNA-binding activity in ova lysates and observed cytoplasmic localization, SpYY1 was not associated with maternal mRNA in ova. SpYY1 expressed in Xenopus oocytes was excluded from the nucleus and associated with maternally expressed cytoplasmic mRNA molecules. These data demonstrate the existence of an YY1 homologue in S. purpuratus with similar structural and biochemical features to those of the well-studied vertebrate YY1; however, the data reveal major differences in the biological role of YY1 in the regulation of maternally expressed mRNA in the two species.
McCarthy, John M; McCann-Crosby, Bonnie M; Rech, Megan E; Yin, Jiani; Chen, Chun-An; Ali, May A; Nguyen, HaiThuy N; Miller, Jennifer L; Schaaf, Christian P
2018-05-01
Nonsense and frameshift mutations in the maternally imprinted, paternally expressed gene MAGEL2, located in the Prader-Willi critical region 15q11-15q13, have been reported to cause Schaaf-Yang syndrome (SYS), a genetic disorder that manifests as developmental delay/intellectual disability, hypotonia, feeding difficulties and autism spectrum disorder. Prader-Willi syndrome (PWS) is a genetic disorder characterised by severe infantile hypotonia, hypogonadotrophic hypogonadism, early childhood onset obesity/hyperphagia, developmental delay/intellectual disability and short stature. Scoliosis and growth hormone insufficiency are also prevalent in PWS.There is extensive documentation of the endocrine and metabolic phenotypes for PWS, but not for SYS. This study served to investigate the hormonal, metabolic and body composition phenotype of SYS and its potential overlap with PWS. In nine individuals with SYS (5 female/4 male; aged 5-17 years), we measured serum ghrelin, glucose, insulin-like growth factor 1 (IGF-1), insulin-like growth factor binding protein 3, follicle-stimulating hormone, luteinising hormone, thyroid-stimulating hormone, free T4, uric acid and testosterone, and performed a comprehensive lipid panel. Patients also underwent X-ray and dual-energy X-ray absorptiometry analyses to assess for scoliosis and bone mineral density. Low IGF-1 levels despite normal weight/adequate nutrition were observed in six patients, suggesting growth hormone deficiency similar to PWS. Fasting ghrelin levels were elevated, as seen in individuals with PWS. X-rays revealed scoliosis >10° in three patients, and abnormal bone mineral density in six patients, indicated by Z-scores of below -2 SDs. This is the first analysis of the hormonal, metabolic and body composition phenotype of SYS. Our findings suggest that there is marked, but not complete overlap between PWS and SYS. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All
Moisá, Sonia J.; Shike, Daniel W.; Meteer, William T.; Keisler, Duane; Faulkner, Dan B.; Loor, Juan J.
2013-01-01
Among 36 differentially-expressed genes during growth in longissimus muscle (LM) of Angus steers, Yin Yang 1 (YY1) had the most relationships with other genes including some associated with adipocyte differentiation. The objective of this study was to examine the effect of nutritional management on mRNA expression of YY1 along with its targets genes PPARG, GTF2B, KAT2B, IGFBP5 and STAT5B. Longissimus from Angus and Angus × Simmental steers (7 total/treatment) on early weaning plus high-starch (EWS), normal weaning plus starch creep feeding (NWS), or normal weaning without starch creep feeding (NWN) was biopsied at 0, 96, and 240 days on treatments. Results suggest that YY1 does not exert control of adipogenesis in LM, and its expression is not sensitive to weaning age. Among the YY1-related genes, EWS led to greater IGFBP5 during growing and finishing phases. Pro-adipogenic transcriptional regulation was detected in EWS due to greater PPARG and VDR at 96 and 240 d vs. 0 d. GTF2B and KAT2B expression was lower in response to NWS and EWS than NWN, and was most pronounced at 240 d. The increase in PPARG and GTF2B expression between 96 and 240 d underscored the existence of a molecular programming mechanism that was sensitive to age and dietary starch. Such response partly explains the greater carcass fat deposition observed in response to NWS. PMID:23700364
Moisá, Sonia J; Shike, Daniel W; Meteer, William T; Keisler, Duane; Faulkner, Dan B; Loor, Juan J
2013-01-01
Among 36 differentially-expressed genes during growth in longissimus muscle (LM) of Angus steers, Yin Yang 1 (YY1) had the most relationships with other genes including some associated with adipocyte differentiation. The objective of this study was to examine the effect of nutritional management on mRNA expression of YY1 along with its targets genes PPARG, GTF2B, KAT2B, IGFBP5 and STAT5B. Longissimus from Angus and Angus × Simmental steers (7 total/treatment) on early weaning plus high-starch (EWS), normal weaning plus starch creep feeding (NWS), or normal weaning without starch creep feeding (NWN) was biopsied at 0, 96, and 240 days on treatments. Results suggest that YY1 does not exert control of adipogenesis in LM, and its expression is not sensitive to weaning age. Among the YY1-related genes, EWS led to greater IGFBP5 during growing and finishing phases. Pro-adipogenic transcriptional regulation was detected in EWS due to greater PPARG and VDR at 96 and 240 d vs. 0 d. GTF2B and KAT2B expression was lower in response to NWS and EWS than NWN, and was most pronounced at 240 d. The increase in PPARG and GTF2B expression between 96 and 240 d underscored the existence of a molecular programming mechanism that was sensitive to age and dietary starch. Such response partly explains the greater carcass fat deposition observed in response to NWS.
NASA Astrophysics Data System (ADS)
Sui, Liansheng; Liu, Benqing; Wang, Qiang; Li, Ye; Liang, Junli
2015-12-01
A color image encryption scheme is proposed based on Yang-Gu mixture amplitude-phase retrieval algorithm and two-coupled logistic map in gyrator transform domain. First, the color plaintext image is decomposed into red, green and blue components, which are scrambled individually by three random sequences generated by using the two-dimensional Sine logistic modulation map. Second, each scrambled component is encrypted into a real-valued function with stationary white noise distribution in the iterative amplitude-phase retrieval process in the gyrator transform domain, and then three obtained functions are considered as red, green and blue channels to form the color ciphertext image. Obviously, the ciphertext image is real-valued function and more convenient for storing and transmitting. In the encryption and decryption processes, the chaotic random phase mask generated based on logistic map is employed as the phase key, which means that only the initial values are used as private key and the cryptosystem has high convenience on key management. Meanwhile, the security of the cryptosystem is enhanced greatly because of high sensitivity of the private keys. Simulation results are presented to prove the security and robustness of the proposed scheme.
Application of Conductive Carbon Nanotube Fibers and Composites: Gas Sensor
2013-05-01
Lee, D.-D. Sensors and Actuators B: Chemical 2005, 108, 298–304. 31. Parikh, K.; Cattanach, K.; Rao , R.; Suh, D.-S.; Wu, A.; Manohar, S. K...Adv Mater 2004, 16, 2049–2052. 53. Zribi, A.; Knobloch, A.; Rao , R. Appl Phys Lett 2005, 86, 203112. 54. Philip, B.; Abraham, J. K.; Chandrasekhar, A...Yujin, C. et al. Nanotechnology 2006, 17, 3012. 61. Krishna Kumar, M.; Leela Mohana Reddy, A.; Ramaprabhu, S. Sensors and Actuators B: Chemical
Analytic Result for the Two-loop Six-point NMHV Amplitude in N = 4 Super Yang-Mills Theory
DOE Office of Scientific and Technical Information (OSTI.GOV)
Dixon, Lance J.; /SLAC; Drummond, James M.
2012-02-15
We provide a simple analytic formula for the two-loop six-point ratio function of planar N = 4 super Yang-Mills theory. This result extends the analytic knowledge of multi-loop six-point amplitudes beyond those with maximal helicity violation. We make a natural ansatz for the symbols of the relevant functions appearing in the two-loop amplitude, and impose various consistency conditions, including symmetry, the absence of spurious poles, the correct collinear behavior, and agreement with the operator product expansion for light-like (super) Wilson loops. This information reduces the ansatz to a small number of relatively simple functions. In order to fix these parametersmore » uniquely, we utilize an explicit representation of the amplitude in terms of loop integrals that can be evaluated analytically in various kinematic limits. The final compact analytic result is expressed in terms of classical polylogarithms, whose arguments are rational functions of the dual conformal cross-ratios, plus precisely two functions that are not of this type. One of the functions, the loop integral {Omega}{sup (2)}, also plays a key role in a new representation of the remainder function R{sub 6}{sup (2)} in the maximally helicity violating sector. Another interesting feature at two loops is the appearance of a new (parity odd) x (parity odd) sector of the amplitude, which is absent at one loop, and which is uniquely determined in a natural way in terms of the more familiar (parity even) x (parity even) part. The second non-polylogarithmic function, the loop integral {tilde {Omega}}{sup (2)}, characterizes this sector. Both {Omega}{sup (2)} and {tilde {Omega}}{sup (2)} can be expressed as one-dimensional integrals over classical polylogarithms with rational arguments.« less
NASA Astrophysics Data System (ADS)
Zhang, Keke; Kong, D.; Schubert, G.; Anderson, J.
2012-10-01
An accurate calculation of the rotationally distorted shape and internal structure of Jupiter is required to understand the high-precision gravitational field that will be measured by the Juno spacecraft now on its way to Jupiter. We present a three-dimensional non-spherical numerical calculation of the shape and internal structure of a model of Jupiter with a polytropic index of unity. The calculation is based on a finite element method and accounts for the full effects of rotation. After validating the numerical approach against the asymptotic solution of Chandrasekhar (1933) that is valid only for a slowly rotating gaseous planet, we apply it to a model of Jupiter whose rapid rotation causes a significant departure from spherical geometry. The two-dimensional distribution of the density and the pressure within Jupiter is then determined via a hybrid inverse approach by matching the a priori unknown coefficient in the equation of state to the observed shape of Jupiter. After obtaining the two-dimensional distribution of Jupiter's density, we then compute the zonal gravity coefficients and the total mass from the non-spherical Jupiter model that takes full account of rotation-induced shape changes. Our non-spherical model with a polytrope of unit index is able to produce the known mass and zonal gravitational coefficients of Jupiter. Chandrasekhar, S. 1933, The equilibrium of distorted polytropes, MNRAS 93, 390
An upper limit on the contribution of accreting white dwarfs to the type Ia supernova rate.
Gilfanov, Marat; Bogdán, Akos
2010-02-18
There is wide agreement that type Ia supernovae (used as standard candles for cosmology) are associated with the thermonuclear explosions of white dwarf stars. The nuclear runaway that leads to the explosion could start in a white dwarf gradually accumulating matter from a companion star until it reaches the Chandrasekhar limit, or could be triggered by the merger of two white dwarfs in a compact binary system. The X-ray signatures of these two possible paths are very different. Whereas no strong electromagnetic emission is expected in the merger scenario until shortly before the supernova, the white dwarf accreting material from the normal star becomes a source of copious X-rays for about 10(7) years before the explosion. This offers a means of determining which path dominates. Here we report that the observed X-ray flux from six nearby elliptical galaxies and galaxy bulges is a factor of approximately 30-50 less than predicted in the accretion scenario, based upon an estimate of the supernova rate from their K-band luminosities. We conclude that no more than about five per cent of type Ia supernovae in early-type galaxies can be produced by white dwarfs in accreting binary systems, unless their progenitors are much younger than the bulk of the stellar population in these galaxies, or explosions of sub-Chandrasekhar white dwarfs make a significant contribution to the supernova rate.
Chiu, Po Yee; Leung, Hoi Yan; Siu, Ada Hoi Ling; Chen, Na; Poon, Michel K T; Ko, Kam Ming
2008-02-01
Previous work in our laboratory has shown that long-term treatment with Vigconic 28 (VI-28), a Yang-invigorating Chinese herbal formula used for the promotion of overall wellness in Chinese medicine, can enhance the mitochondrial functional ability and antioxidant capacity in various tissues of both male and female rats. To investigate whether the VI-28 treatment regimen could afford tissue protection against oxidative injury, the effects of long-term VI-28 treatment (80 or 240 mg/kg/d x 30) on oxidative stress-induced tissue damage in various organs (brain, heart, liver, and kidney) were examined in female rats. The results indicated that long-term VI-28 treatment invariably protected against oxidative tissue damage in the rat models of cerebral/myocardial ischemia-reperfusion injury, CCl4 hepatotoxicity, and gentamicin nephrotoxicity. The tissue protection was associated with increases in the levels and activities of mitochondrial antioxidant components as well as with the preservation of mitochondrial structural integrity. This was evidenced by decreases in the sensitivity of mitochondria to Ca2+-induced permeability transition, and in the levels of mitochondrial malondialdehyde production, Ca2+ loading, and cytochrome c release in the tissues examined. Interestingly, the VI-28 treatment increased red cell CuZn-superoxide dismutase (CuZn-SOD) levels, and these levels correlated positively with the degree of tissue protection afforded by long-term VI-28 treatment in rats. The generalized tissue protection afforded by long-term VI-28 treatment may have clinical implications in the prevention of age-related diseases, and VI-28 treatment may possibly delay the aging process.
Mário Schenberg: Physicist, politician and art critic
NASA Astrophysics Data System (ADS)
Guzzo, M. M.; Reggiani, N.
2015-12-01
Mário Schenberg is considered one of the greatest theoretical physicists of Brazil. He worked in different fields of physics including thermodynamics, quantum mechanics, statistical mechanics, general relativity, astrophysics and mathematics. He was assistant of the Ukrainian naturalized Italian physicist Gleb Wataghin and worked with prestigious physicists like as the Brazilians José Leite Lopes and César Lattes, the Russian-born American George Gamow and the Indian astrophysicist Subrahmanyan Chandrasekhar. Besides, he was also an active politician and critic of art.
Mário Schenberg: Physicist, politician and art critic
DOE Office of Scientific and Technical Information (OSTI.GOV)
Guzzo, M. M., E-mail: guzzo@ifi.unicamp.br; Reggiani, N.
2015-12-17
Mário Schenberg is considered one of the greatest theoretical physicists of Brazil. He worked in different fields of physics including thermodynamics, quantum mechanics, statistical mechanics, general relativity, astrophysics and mathematics. He was assistant of the Ukrainian naturalized Italian physicist Gleb Wataghin and worked with prestigious physicists like as the Brazilians José Leite Lopes and César Lattes, the Russian-born American George Gamow and the Indian astrophysicist Subrahmanyan Chandrasekhar. Besides, he was also an active politician and critic of art.
NASA Astrophysics Data System (ADS)
McReynolds, Sean
Five-dimensional N = 2 Yang-Mills-Einstein supergravity and its couplings to hyper and tensor multiplets are considered on an orbifold spacetime of the form M4 x S1/Gamma, where Gamma is a discrete group. As is well known in such cases, supersymmetry is broken to N = 1 on the orbifold fixed planes, and chiral 4D theories can be obtained from bulk hypermultiplets (or from the coupling of fixed-plane supported fields). Five-dimensional gauge symmetries are broken by boundary conditions for the fields, which are equivalent to some set of Gamma-parity assignments in the orbifold theory, allowing for arbitrary rank reduction. Furthermore, Wilson lines looping from one boundary to the other can break bulk gauge groups, or give rise to vacuum expectation values for scalars on the boundaries, which can result in spontaneous breaking of boundary gauge groups. The broken gauge symmetries do not survive as global symmetries of the low energy theories below the compactification scale due to 4 D minimal couplings to gauge fields. Axionic fields are a generic feature, just as in any compactification of M-theory (or string theory for that matter), and we exhibit the form of this field and its role as the QCD axion, capable of resolving the strong CP problem. The main motivation for the orbifold theories here is taken to be orbifold-GUTS, wherein a unified gauge group is sought in higher dimensions while allowing the orbifold reduction to handle problems such as rapid proton decay, exotic matter, mass hierarchies, etc. To that end, we discuss the allowable minimal SU(5), SO(10) and E6 GUT theories with all fields living in five dimensions. It is argued that, within the class of homogeneous quaternionic scalar manifolds characterizing the hypermultiplet couplings in 5D, supergravity admits a restricted set of theories that yield minimal phenomenological field content. In addition, non-compact gaugings are a novel feature of supergravity theories, and in particular we consider the
Cellular traditional Chinese medicine on photobiomodulation
NASA Astrophysics Data System (ADS)
Liu, Timon Cheng-Yi; Cheng, Lei; Liu, Jiang; Wang, Shuang-Xi; Xu, Xiao-Yang; Deng, Xiao-Yuan; Liu, Song-Hao
2006-09-01
Although yin-yang is one of the basic models of traditional Chinese medicine (TCM) for TCM objects such as whole body, five zangs or six fus, they are widely used to discuss cellular processes in papers of famous journals such as Cell, Nature, or Science. In this paper, the concept of the degree of difficulty (DD) of a process was introduced to redefine yin and yang and extend the TCM yin-yang model to the DD yin-yang model so that we have the DD yin-yang inter-transformation, the DD yin-yang antagonism, the DD yin-yang interdependence and the DD yin ping yang mi, which and photobiomodulation (PBM) on cells are supported by each other. It was shown that healthy cells are in the DD yin ping yang mi so that there is no PBM, and there is PBM on non-healthy cells until the cells become healthy so that PBM can be called a cellular rehabilitation. The DD yin-yang inter-transformation holds for our biological information model of PBM. The DD yin-yang antagonism and the DD yin-yang interdependence also hold for a series of experimental studies such as the stimulation of DNA synthesis in HeLa cells after simultaneous irradiation with narrow-band red light and a wide-band cold light, or consecutive irradiation with blue and red light.
An Accreting White Dwarf near the Chandrasekhar Limit in the Andromeda Galaxy
NASA Technical Reports Server (NTRS)
Tang, Sumin; Bildsten, Lars; Wolf, William M.; Li, K. L.; Kong, Albert K. H.; Cao, Yi; Cenko, S. Bradley; De Cia, Annalisa; Kasliwal, Mansi M.; Kulkarni, Shrinivas R.;
2014-01-01
The iPTF (Intermediate Palomar Transient Factory) detection of the most recent outburst of the recurrent nova system RX J0045.4+4154 in the Andromeda Galaxy has enabled the unprecedented study of a massive (mass is greater than 1.3 solar masses) accreting white dwarf (WD). We detected this nova as part of the near daily iPTF monitoring of M31 to a depth of R (red band-pass filter) approximately equal to magnitude 21 and triggered optical photometry, spectroscopy and soft X-ray monitoring of the outburst. Peaking at an absolute magnitude of MR (red, mid-infrared band-pass filter) equals magnitude -6.6, and with a decay time of 1 magnitude per day, it is a faint and very fast nova. It shows optical emission lines of He/N and expansion velocities of 1900 to 2600 kilometers per second 1-4 days after the optical peak. The Swift monitoring of the X-ray evolution revealed a supersoft source (SSS) with kT (energy: Boltzmann constant times temperature) (sub eff (effective)) approximately equal to 90-110 electronvolts that appeared within 5 days after the optical peak, and lasted only 12 days. Most remarkably, this is not the first event from this system, rather it is a recurrent nova with a time between outbursts of approximately 1 year, the shortest known. Recurrent X-ray emission from this binary was detected by ROSAT in 1992 and 1993, and the source was well characterized as a mass greater than 1.3 solar masses WD SSS. Based on the observed recurrence time between different outbursts, the duration and effective temperature of the SS phase, MESA models of accreting WDs allow us to constrain the accretion rate to mass greater than 1.7x10 (sup -7) solar masses per year and WD mass greater than 1.30 solar masses. If the WD keeps 30 percent of the accreted material, it will take less than a million years to reach core densities high enough for carbon ignition (if made of C/O) or electron capture (if made of O/Ne) to end the binary evolution.
An accreting white dwarf near the Chandrasekhar limit in the Andromeda galaxy
DOE Office of Scientific and Technical Information (OSTI.GOV)
Tang, Sumin; Bildsten, Lars; Wolf, William M.
The intermediate Palomar Transient Factory (iPTF) detection of the most recent outburst of the recurrent nova (RN) system RX J0045.4+4154 in the Andromeda galaxy has enabled the unprecedented study of a massive (M > 1.3 M {sub ☉}) accreting white dwarf (WD). We detected this nova as part of the near-daily iPTF monitoring of M31 to a depth of R ≈ 21 mag and triggered optical photometry, spectroscopy and soft X-ray monitoring of the outburst. Peaking at an absolute magnitude of M{sub R} = –6.6 mag, and with a decay time of 1 mag per day, it is a faintmore » and very fast nova. It shows optical emission lines of He/N and expansion velocities of 1900-2600 km s{sup –1} 1-4 days after the optical peak. The Swift monitoring of the X-ray evolution revealed a supersoft source (SSS) with kT {sub eff} ≈ 90-110 eV that appeared within 5 days after the optical peak, and lasted only 12 days. Most remarkably, this is not the first event from this system, rather it is an RN with a time between outbursts of approximately 1 yr, the shortest known. Recurrent X-ray emission from this binary was detected by ROSAT in 1992 and 1993, and the source was well characterized as a M > 1.3 M {sub ☉} WD SSS. Based on the observed recurrence time between different outbursts, the duration and effective temperature of the SS phase, MESA models of accreting WDs allow us to constrain the accretion rate to M-dot >1.7×10{sup −7} M{sub ⊙} yr{sup −1} and WD mass >1.30 M {sub ☉}. If the WD keeps 30% of the accreted material, it will take less than a Myr to reach core densities high enough for carbon ignition (if made of C/O) or electron capture (if made of O/Ne) to end the binary evolution.« less
Positronium formation in e+ plus H- collisions
NASA Technical Reports Server (NTRS)
Straton, Jack C.; Drachman, Richard J.
1990-01-01
Cross sections for positronium formation by capture from the negative hydrogen ion are given. Orthogonalization corrections to the Coulomb (First) Born Approximation (CBA) differential and total cross sections are calculated using approximate H- wave functions of both Lowdin and Chandrasekhar. Various methods of orthogonalizing the unbound projectile to the possible bound states are considered. It is found that treating the atomic nuclei as if they were isotopic spin projections of a single type of nucleon gives cross sections that are an improvement over the CBA.
The White Dwarf Mass and the Accretion Rate of Recurrent Novae: An X-ray Perspective
NASA Technical Reports Server (NTRS)
Mukai, Koji; Sokoloski, Jennifer L.; Nelson, Thomas; Luna, Gerardo J. M.
2011-01-01
We present recent results of quiescent X-ray observations of recurrent novae (RNe) and related objects. Several RNe are luminous hard X-ray sources in quiescence, consistent with accretion onto a near Chandrasekhar mass white dwarf. Detection of similar hard X-ray emissions in old novae and other cataclysmic variables may lead to identification of additional RN candidates. On the other hand, other RNe are found to be comparatively hard X-ray faint. We present several scenarios that may explain this dichotomy, which should be explored further.
White Dwarf Critical Tests for Modified Gravity.
Jain, Rajeev Kumar; Kouvaris, Chris; Nielsen, Niklas Grønlund
2016-04-15
Scalar-tensor theories of gravity can lead to modifications of the gravitational force inside astrophysical objects. We exhibit that compact stars such as white dwarfs provide a unique setup to test beyond Horndeski theories of G^{3} type. We obtain stringent and independent constraints on the parameter ϒ characterizing the deviations from Newtonian gravity using the mass-radius relation, the Chandrasekhar mass limit, and the maximal rotational frequency of white dwarfs. We find that white dwarfs impose stronger constraints on ϒ than red and brown dwarfs.
Choi, Yookeum; Kim, Seul-Ki; Choi, In-Young; Ju, Chung; Nam, Kung-Woo; Hwang, Sunyoung; Kim, Byung-Woo; Yoon, Min Ji; Won, Moo-Ho; Park, Yong-Ki; Kim, Won-Ki
2011-05-01
Modified Bo-Yang-Hwan-O-Tang (mBHT) is an improved herbal formula of BHT, which has been widely used to treat ischaemic stroke in East Asia, by the addition of five herbs having anti-ischaemic properties. In this study, we investigated whether mBHT would reduce cerebral ischaemic injury in rats. Sprague-Dawley rats were subjected to a 90-min middle cerebral artery occlusion (MCAO) and subsequent 22-h reperfusion. mBHT was administered either intraperitoneally twice 15 min before and 15 min after, or orally once 30 min or 120 min after the onset of MCAO (50 or 200 mg/kg each). Intraperitoneal administration of mBHT markedly reduced the cerebral infarct size and neurological deficit caused by MCAO/reperfusion. mBHT treatment also significantly improved long-term survival rate after cerebral ischaemic injury. Oral administration of mBHT 30 min after ischaemia also markedly reduced the infarct size after cerebral ischaemia. The anti-ischaemic effect of mBHT was significantly, but not fully, reduced when mBHT-induced hypothermia was abolished. In cultured cortical neurons, we further found that mBHT decreased oxygen-glucose deprivation/re-oxygenation-evoked neuronal injury by inhibiting production of reactive oxygen species, decrease in mitochondrial transmembrane potential, and activation of caspase-3. However, mBHT did not inhibit N-Methyl-D-aspartate (NMDA) receptor-mediated excitotoxicity. Taken together, our data suggest that mBHT has multiple anti-ischaemic properties and would be a good therapeutic herbal prescription for the treatment of cerebral ischaemic stroke. © 2011 The Authors. JPP © 2011 Royal Pharmaceutical Society.
Yang, Zai-hua; Hauser, Martin; Yang, Mao-fa; Zhang, Ting-ting
2013-01-01
In this paper, three new species of Nasimyia Yang & Yang, 2010, N. eurytarsa sp. nov., N. rozkosnyi sp. nov. and N. elongoverpa sp. nov. from the Oriental region are described and illustrated; N. nigripennis Yang & Yang, 2010 is found to be a junior synonym of N. megacephala Yang & Yang, 2010 (syn. nov.). Chelonomima signata de Meijere 1924 is combined as Pseudomeristomerinx signata (de Meijere, 1924) comb. nov.. Keys to the Oriental genera of Pachygasterinae with elongate abdomens and the species of Nasimyia are provided, as well as distribution maps of the four species of Nasimyia.
Kompor, Pontip; Muang Karn, Rattikarn; Norkaew, Jun; Kujapun, Jirawoot; Photipim, Mali; Ponphimai, Sukanya; Chavengkun, Wasugree; Phong Paew, Somkiat; Kaewpitoon, Soraya; Rujirakul, Ratana; Wakhuwathapong, Parichart; Phatisena, Tanida; Eaksanti, Thawatchai; Joosiri, Apinya; Polsripradistdist, Poowadol; Padchasuwan, Natnapa; Kaewpitoon, Natthawut
2016-01-01
Opisthorchiasis is still a major health problem in rural communities of Thailand. Infection is associated with cholangiocarcinoma (CCA), which is found frequently in Thailand, particularly in the northeastern. Therefore, this study aimed to evaluate the effectiveness of health intervention in the population at risk for opisthorchiasis and CCA. A quasi-experimental study was conducted in Meuang Yang district, Nakhon Ratchasima province, northeastern Thailand, between June and October 2015. Participants were completed health intervention comprising 4 stations; 1, VDO clip of moving adult worm of liver fluke; 2, poster of life cycle of liver fluke; 3, microscopy with adult and egg liver fluke; and 4, brochure with the knowledge of liver fluke containing infection, signs, symptoms, related disease, diagnosis, treatment, prevention, and control. Pre-and-post-test questionnaires were utilized to collect data from all participants. Students paired t-tests were used to analyze differences between before and after participation in the health intervention. Knowledge (mean difference=-7.48, t=-51.241, 95% CI, -7.77, -7.19, p-value =0.001), attitude (mean difference=-9.07, t=-9.818, 95% CI=-10.9, -7.24, p-value=0.001), and practice (mean difference=-2.04, t=-2.688, 95% CI=-3.55, -0.53, p-value=0.008), changed between before and after time points with statistical significance. Community rules were concluded regarding: (1) cooked cyprinoid fish consumption; (2) stop under cooked cyprinoid fish by household cooker; (3) cooked food consumption; (4) hygienic defecation; (5) corrected knowledge campaign close to each household; (6) organizing a village food safety club; (7) and annual health check including stool examination featuring monitoring by village health volunteers and local public health officers. The results indicates that the present health intervention program was effective and easy to understand, with low cost and taking only a short time. Therefore, this program may
Effect of minimal length uncertainty on the mass-radius relation of white dwarfs
NASA Astrophysics Data System (ADS)
Mathew, Arun; Nandy, Malay K.
2018-06-01
Generalized uncertainty relation that carries the imprint of quantum gravity introduces a minimal length scale into the description of space-time. It effectively changes the invariant measure of the phase space through a factor (1 + βp2) - 3 so that the equation of state for an electron gas undergoes a significant modification from the ideal case. It has been shown in the literature (Rashidi 2016) that the ideal Chandrasekhar limit ceases to exist when the modified equation of state due to the generalized uncertainty is taken into account. To assess the situation in a more complete fashion, we analyze in detail the mass-radius relation of Newtonian white dwarfs whose hydrostatic equilibria are governed by the equation of state of the degenerate relativistic electron gas subjected to the generalized uncertainty principle. As the constraint of minimal length imposes a severe restriction on the availability of high momentum states, it is speculated that the central Fermi momentum cannot have values arbitrarily higher than pmax ∼β - 1 / 2. When this restriction is imposed, it is found that the system approaches limiting mass values higher than the Chandrasekhar mass upon decreasing the parameter β to a value given by a legitimate upper bound. Instead, when the more realistic restriction due to inverse β-decay is considered, it is found that the mass and radius approach the values 1.4518 M⊙ and 601.18 km near the legitimate upper bound for the parameter β.
NASA Astrophysics Data System (ADS)
Mazzali, P. A.; Ashall, C.; Pian, E.; Stritzinger, M. D.; Gall, C.; Phillips, M. M.; Höflich, P.; Hsiao, E.
2018-05-01
The nebular-epoch spectrum of the rapidly declining, `transitional' Type Ia supernova (SN) 2007on showed double emission peaks, which have been interpreted as indicating that the SN was the result of the direct collision of two white dwarfs. The spectrum can be reproduced using two distinct emission components, one redshifted and one blueshifted. These components are similar in mass but have slightly different degrees of ionization. They recede from one another at a line-of-sight speed larger than the sum of the combined expansion velocities of their emitting cores, thereby acting as two independent nebulae. While this configuration appears to be consistent with the scenario of two white dwarfs colliding, it may also indicate an off-centre delayed detonation explosion of a near-Chandrasekhar-mass white dwarf. In either case, broad emission line widths and a rapidly evolving light curve can be expected for the bolometric luminosity of the SN. This is the case for both SNe 2007on and 2011iv, also a transitional SN Ia that exploded in the same elliptical galaxy, NGC 1404. Although SN 2011iv does not show double-peaked emission line profiles, the width of its emission lines is such that a two-component model yields somewhat better results than a single-component model. Most of the mass ejected is in one component, however, which suggests that SN 2011iv was the result of the off-centre ignition of a Chandrasekhar-mass white dwarf.
M31N 2008-12a: The Remarkable Recurrent Nova in the Andromeda Galaxy
NASA Astrophysics Data System (ADS)
Shafter, Allen W.; Darnley, Matthew; Henze, Martin; Williams, Steven C.
2017-08-01
The recurrent nova M31N 2008-12a in M31 has the shortest interoutburst time of any known recurrent nova. Since its discovery in December 2008 by two Japanese amateur astronomers, Koichi Nishiyama and Fujio Kabashima, a total of 8 subsequent outbursts have been observed. The mean time between observed eruptions (all observed between late August and December) is 364+/-52 days. M31 is close to the sun in March through May, so it is likely that any eruptions that may have occurred during this period have been missed and the recurrence period could be as short as 6 months. Models of thermonuclear runaways on white dwarfs show that only near Chandrasekhar mass white dwarfs accreting at a few times 10-7 solar masses per year can produce nova outbursts with a recurrence time of a year, or less. Furthermore, the models show that during the interval between each nova event the accreted mass is expected to be greater than the expelled mass. The white dwarf mass must therefore be growing, and is predicted to reach the Chandrasekhar mass in of order 500,000 years. Thus, M31N 2008-12a is destined either to become a Type Ia supernova (if the white dwarf has a CO composition) or to form a neutron star in an accretion-induced collapse (if the white dwarf has an ONe composition). In this poster, I will describe the latest observations of this fascinating nova.
"Yin and Yang" tuned fluorescence sensing behavior of branched 1,4-bis(phenylethynyl)benzene.
Sun, Xiaohuan; Qi, Yanyu; Liu, Huijing; Peng, Junxia; Liu, Kaiqiang; Fang, Yu
2014-11-26
Achieving high sensing performance and good photostability of fluorescent films based on adlayer construction represents a significant challenge in the area of functional fluorescent film research. A solution may be offered by "Yin and Yang", a balance idea from Chinese philosophy, for the design of a fluorophore and the relevant assembly. Accordingly, a 1,4-bis(phenylethynyl)benzene (BPEB) derivative (C2) with two cholesteryl residues in the side chains and two glucono units in the head and tail positions was designed and synthesized. As a control, compound C1 was also prepared. The only difference between C1 and C2 is that the hydroxyl groups in the glucono residues of C1 are fully acetylated. Studies of the fluorescence behaviors of the two compounds in solution revealed that both the profile and the intensity of the fluorescence emission of the compounds, in particular C2, are dependent on their concentration and on the nature of solvents employed. Presence of HCl also alters the emission of the compounds in solution. On the basis of the studies, three fluorescent films were prepared, and their sensing performances to HCl in vapor state were studied. Specifically, Film 1 and Film 3 were fabricated via physical coating, separately, of C2 and C1 on glass plate surfaces. As another comparison, Film 2 was also fabricated with C2 as a fluorophore but at a much lower concentration if compared to that for the preparation of Film 1. As revealed by SEM and fluorescent microscopy studies, Film 1 and Film 2 exhibit well-defined microstructures, which are spherical particles and spherical pores, respectively, while Film 3 is characterized by irregular aggregates of C1. Fluorescence measurements demonstrated that Film 1 and Film 3 both display an aggregation emission, of which the emission from Film 1 is supersensitive to the presence of HCl vapor (detection limit: 0.4 ppb, a lowest value reported in the literatures). For Film 3, however, its emission is insensitive to the
THE STABILITY OF THE PINCH WITH ANISOTROPIC PRESSURE
DOE Office of Scientific and Technical Information (OSTI.GOV)
Jaggi, R.K.
1961-12-01
A dispersion equation was obtained for the stability of the pinch from the hydromagnetic equations supplemented by an equation for the pressure tensor of the ions. The dispersion equation was obtained for the marginal instability case only. It was observed that this dispersion equation coincides with the dispersion equation obtained from the Chew, Goldberger, and Low equations for the marginal instability case. It was concluded that the region of stability predicted from the equations that were used is slightly more than given by the kinetic equation used by Chandrasekhar, Kaufmann, and Watson. (auth)
Scattering of Dirac waves off Kerr black holes
NASA Astrophysics Data System (ADS)
Chakrabarti, Sandip K.; Mukhopadhyay, Banibrata
2000-10-01
Chandrasekhar separated the Dirac equation for spinning and massive particles in Kerr geometry into radial and angular parts. Here we solve the complete wave equation and find out how the Dirac wave scatters off Kerr black holes. The eigenfunctions, eigenvalues and reflection and transmission co-efficients are computed. We compare the solutions with several parameters to show how a spinning black hole recognizes the mass and energy of incoming waves. Very close to the horizon the solutions become independent of the particle parameters, indicating the universality of the behaviour.
NASA Astrophysics Data System (ADS)
Kartono, R.; Basuki, Y. T.
2014-03-01
The purpose of this paper is to examine the sets of model and literature review to prove that strategy of applying free chemical usage in purified water system for pharmaceutical industry would be help the existing and new pharmaceutical companies to comply with part of Natioanal Agency of Drug and Food Control / Badan Pengawas Obat dan Makanan (NADFC/BPOM) regulation in order to achieve "Cara Pembuatan Obat yang Baik" (CPOB) of Indonesia pharmaceutical industry. One of the main reasons is when we figured out the number of Indonesian pharmaceutical industries in 2012 are kept reducing compare to the increasing numbers of Indonesian population growth. This strategy concept also might help the industries to reducing environmental pollution, and operational cost in pharmaceutical industries, by reducing of the chemical usage for water treatment process in floculation and cougulation and chlorination for sterillization. This new model is free usage of chemicals for purified water generation system process and sterilization. The concept offering of using membrane technology- Reverse Osmosis (RO) membrane base treatment to replace traditional chemical base treatment, following enhance Electrodeionization (EDI) as final polisher for controlling conductivity, and finally Ultra Violet (UV) disinfectant technology as final guard for bacteria controls instead of chemical base system in purified water generation system.
Yue, Patrick Ying Kit; Mak, Nai Ki; Cheng, Yuen Kit; Leung, Kar Wah; Ng, Tzi Bun; Fan, David Tai Ping; Yeung, Hin Wing; Wong, Ricky Ngok Shun
2007-01-01
In Chinese medicine, ginseng (Panax ginseng C.A. Meyer) has long been used as a general tonic or an adaptogen to promote longevity and enhance bodily functions. It has also been claimed to be effective in combating stress, fatigue, oxidants, cancer and diabetes mellitus. Most of the pharmacological actions of ginseng are attributed to one type of its constituents, namely the ginsenosides. In this review, we focus on the recent advances in the study of ginsenosides on angiogenesis which is related to many pathological conditions including tumor progression and cardiovascular dysfunctions. Angiogenesis in the human body is regulated by two sets of counteracting factors, angiogenic stimulators and inhibitors. The 'Yin and Yang' action of ginseng on angiomodulation was paralleled by the experimental data showing angiogenesis was indeed related to the compositional ratio between ginsenosides Rg1 and Rb1. Rg1 was later found to stimulate angiogenesis through augmenting the production of nitric oxide (NO) and vascular endothelial growth factor (VEGF). Mechanistic studies revealed that such responses were mediated through the PI3K→Akt pathway. By means of DNA microarray, a group of genes related to cell adhesion, migration and cytoskeleton were found to be up-regulated in endothelial cells. These gene products may interact in a hierarchical cascade pattern to modulate cell architectural dynamics which is concomitant to the observed phenomena in angiogenesis. By contrast, the anti-tumor and anti-angiogenic effects of ginsenosides (e.g. Rg3 and Rh2) have been demonstrated in various models of tumor and endothelial cells, indicating that ginsenosides with opposing activities are present in ginseng. Ginsenosides and Panax ginseng extracts have been shown to exert protective effects on vascular dysfunctions, such as hypertension, atherosclerotic disorders and ischemic injury. Recent work has demonstrates the target molecules of ginsenosides to be a group of nuclear steroid
Huerta-Yepez, Sara; Vega, Mario; Escoto-Chavez, Saul E; Murdock, Benjamin; Sakai, Toshiyuki; Baritaki, Stavroula; Bonavida, Benjamin
2009-02-01
Treatment of TRAIL-resistant tumor cells with the nitric oxide donor DETANONOate sensitizes the tumor cells to TRAIL-induced apoptosis concomitantly with DR5 upregulation. The mechanism of sensitization was examined based on the hypothesis that DETANONOate inhibits a transcription repressor Yin Yang 1 (YY1) that negatively regulates DR5 transcription. Treatment of the prostate carcinoma cell lines with DETANONOate inhibited both NF-kappaB and YY1 DNA-binding activities concomitantly with upregulation of DR5 expression. The direct role of YY1 in the regulation of TRAIL resistance was demonstrated in cells treated with YY1 siRNA resulting in TRAIL-induced apoptosis. The role of YY1 in the transcriptional regulation of DR5 was examined in cells treated with a DR5 luciferase reporter system (pDR5) and two constructs, namely, the pDR5/-605 construct with a deletion of the putative YY1 DNA-binding region (-1224 to -605) and a construct pDR5-YY1 with a mutation of the YY1 DNA-binding site. A significant (3-fold) augmentation of luciferase activity over baseline transfection with pDR5 was observed in cells transfected with the modified constructs. ChIP analysis corroborated the YY1 binding to the DR5 promoter. In vivo, tissues from nude mice bearing the PC-3 xenograft and treated with DETANONOate showed inhibition of YY1 and upregulation of DR5. The present findings demonstrate that YY1 negatively regulates DR5 transcription and expression and these correlated with resistance to TRAIL-induced apoptosis. DETANONOate inhibits both NF-kappaB and YY1 and in combination with TRAIL reverses tumor cell resistance to TRAIL apoptosis.
Zeng, Ling-na; Ma, Zhi-jie; Zhao, Yan-ling; Zhang, Lin-dong; Li, Rui-sheng; Wang, Jia-bo; Zhang, Ping; Yan, Dan; Li, Qi; Jiang, Bing-qian; Pu, Shi-biao; Lü, Yang; Xiao, Xiao-he
2013-02-15
Chromium nephrotoxicity (CrNT) is thought to occur through the oxidant lesion mechanism. There is still a lack of specific remedies against CrNT. We primarily screened Chinese herbal medicines with a potential protective effect against CrNT, e.g., rhubarb (Rheum palmatum L.). However, the active constituents in rhubarb and its mechanisms remain unclear. In this study, the total rhubarb extract (TR) was successively separated into three parts: total anthraquinone extract (TA), total tannin extract (TT) and remaining component extract (RC). The effects of each extract on the potassium dichromate (K(2)Cr(2)O(7))-induced nephrotoxicity in rats were comparatively assessed. The results showed that only the administration of TT protected the kidney function in K(2)Cr(2)O(7)-injured rats. Besides, TT showed significant activity to scavenge hydroxyl radicals, which is considered to be the dominant lesion product generated by hexavalent chromium. TT also showed a reduced ability to transform toxic high valence chromium ions into non-toxic low valence ions. And TT was able to further precipitate chromium ions. These results suggested that rhubarb tannins treat CrNT as a free radical scavenger, reductant, and metal precipitant. The multiple protective routes of the plant tannins reveal a superior option for development into a promising natural remedy against CrNT. In addition, the opposite effects of rhubarb anthraquinones in treating CrNT were observed compared to rhubarb tannins, which suggested the duo-directional effects (Yin and Yang) of herbal medicines should be addressed. Copyright © 2012 Elsevier B.V. All rights reserved.
Theoretical models of highly magnetic white dwarf stars that violate the Chandrasekhar Limit
NASA Astrophysics Data System (ADS)
Shah, Hridaya
2017-08-01
Until recently, white dwarf (WD) stars were believed to be no more massive than 1.44 solar masses (M ⊙ ). This belief has been changed now with the observations of over-luminous or 'peculiar' Type la supernovae that have lead researchers to hypothesize the existence of WDs in the mass range 2.4 - 2.8 M ⊙ . This discovery also raises some doubt over the reliability of the Type Ia supernova as a standard candle. It is thought that these super-massive WDs are their most likely progenitors and that they probably have a very strong magnetic field inside them. A degenerate electron gas in a magnetic field, such as that present inside this star, will be Landau quantized. Magnetic field changes the momentum space of electrons which in turn changes their density of states (DOS) and that in turn changes the equation of state (EoS) of matter inside the star, as opposed to that without a field. When this change in the DOS is taken into account and a link between the DOS and the EoS is established, as is done in this work, I find a physical reason behind the theoretical mass-radius (M-R) relations of a super-massive WD. I start with different equations of state with at most three Landau levels occupied and then construct stellar models of magnetic WDs (MWDs) using the same. I also show the M-R relations of these stars for a particular chosen value of maximum electron Fermi energy. Once a multiple Landau level system of electrons is considered, I find that it leads to such an EoS that gives multiple branches in the MR relations. Super-massive MWDs are obtained only when the Landau level occupancy is limited to just one level and some of the mass values fall within the mass range given above.
On the resonant detonation of sub-Chandrasekhar mass white dwarfs during binary inspiral
NASA Astrophysics Data System (ADS)
McKernan, B.; Ford, K. E. S.
2016-12-01
White dwarfs (WDs) are believed to detonate via explosive Carbon-fusion in a Type Ia supernova (SN) when their temperature and/or density reach the point where Carbon is ignited in a runaway reaction. Observations of the Type Ia SN rate imply that all WD binaries that merge through the emission of gravitational radiation within a Hubble time should result in SNe, regardless of total mass. Here we investigate the conditions under which a single WD in a binary system might extract energy from its orbit, depositing enough energy into a resonant mode such that it detonates before merger. We show that, ignoring non-linear effects in a WD binary in tidal lock at small binary separations, the sustained tidal forcing of a low-order quadrupolar g mode or a harmonic of a low-order quadrupolar p mode could, in principle, drive the average temperature of Carbon nuclei in the mode over the runaway fusion threshold. If growing mode energy is thermalized at a core/atmosphere boundary, rapid Helium burning and inwards-travelling p-waves may result in core detonation. Thermalization at a boundary in the core can also result in detonation. If energy can be efficiently transferred from the orbit to modes as the WD binary passes through resonances, the WD merger time-scale will be shortened by Myr-Gyr compared to expected time-scales from gravitational wave (GW)-emission alone and GW detectors will observe deviations from predicted chirp profiles in resolved WD binaries. Future work in this area should focus on whether tidal locking in WD binaries is naturally driven towards low-order mode frequencies.
A hybrid type Ia supernova with an early flash triggered by helium-shell detonation
NASA Astrophysics Data System (ADS)
Jiang, Ji-An; Doi, Mamoru; Maeda, Keiichi; Shigeyama, Toshikazu; Nomoto, Ken'Ichi; Yasuda, Naoki; Jha, Saurabh W.; Tanaka, Masaomi; Morokuma, Tomoki; Tominaga, Nozomu; Ivezić, Željko; Ruiz-Lapuente, Pilar; Stritzinger, Maximilian D.; Mazzali, Paolo A.; Ashall, Christopher; Mould, Jeremy; Baade, Dietrich; Suzuki, Nao; Connolly, Andrew J.; Patat, Ferdinando; Wang, Lifan; Yoachim, Peter; Jones, David; Furusawa, Hisanori; Miyazaki, Satoshi
2017-10-01
Type Ia supernovae arise from the thermonuclear explosion of white-dwarf stars that have cores of carbon and oxygen. The uniformity of their light curves makes these supernovae powerful cosmological distance indicators, but there have long been debates about exactly how their explosion is triggered and what kind of companion stars are involved. For example, the recent detection of the early ultraviolet pulse of a peculiar, subluminous type Ia supernova has been claimed as evidence for an interaction between a red-giant or a main-sequence companion and ejecta from a white-dwarf explosion. Here we report observations of a prominent but red optical flash that appears about half a day after the explosion of a type Ia supernova. This supernova shows hybrid features of different supernova subclasses, namely a light curve that is typical of normal-brightness supernovae, but with strong titanium absorption, which is commonly seen in the spectra of subluminous ones. We argue that this early flash does not occur through previously suggested mechanisms such as the companion-ejecta interaction. Instead, our simulations show that it could occur through detonation of a thin helium shell either on a near-Chandrasekhar-mass white dwarf, or on a sub-Chandrasekhar-mass white dwarf merging with a less-massive white dwarf. Our finding provides evidence that one branch of previously proposed explosion models—the helium-ignition branch—does exist in nature, and that such a model may account for the explosions of white dwarfs in a mass range wider than previously supposed.
Thermal convection in a magnetized conducting fluid with the Cattaneo–Christov heat-flow model
2016-01-01
By substituting the Cattaneo–Christov heat-flow model for the more usual parabolic Fourier law, we consider the impact of hyperbolic heat-flow effects on thermal convection in the classic problem of a magnetized conducting fluid layer heated from below. For stationary convection, the system is equivalent to that studied by Chandrasekhar (Hydrodynamic and Hydromagnetic Stability, 1961), and with free boundary conditions we recover the classical critical Rayleigh number Rc(c)(Q) which exhibits inhibition of convection by the field according to Rc(c)→π2Q as Q→∞, where Q is the Chandrasekhar number. However, for oscillatory convection we find that the critical Rayleigh number Rc(o)(Q,P1,P2,C) is given by a more complicated function of the thermal Prandtl number P1, magnetic Prandtl number P2 and Cattaneo number C. To elucidate features of this dependence, we neglect P2 (in which case overstability would be classically forbidden), and thereby obtain an expression for the Rayleigh number that is far less strongly inhibited by the field, with limiting behaviour Rc(o)→πQ/C, as Q→∞. One consequence of this weaker dependence is that onset of instability occurs as overstability provided C exceeds a threshold value CT(Q); indeed, crucially we show that when Q is large, CT∝1/Q, meaning that oscillatory modes are preferred even when C itself is small. Similar behaviour is demonstrated in the case of fixed boundaries by means of a novel numerical solution. PMID:27956886
Thermal convection in a magnetized conducting fluid with the Cattaneo-Christov heat-flow model
NASA Astrophysics Data System (ADS)
Bissell, J. J.
2016-11-01
By substituting the Cattaneo-Christov heat-flow model for the more usual parabolic Fourier law, we consider the impact of hyperbolic heat-flow effects on thermal convection in the classic problem of a magnetized conducting fluid layer heated from below. For stationary convection, the system is equivalent to that studied by Chandrasekhar (Hydrodynamic and Hydromagnetic Stability, 1961), and with free boundary conditions we recover the classical critical Rayleigh number Rc(c )(Q ) which exhibits inhibition of convection by the field according to Rc(c )→π2Q as Q →∞ , where Q is the Chandrasekhar number. However, for oscillatory convection we find that the critical Rayleigh number Rc(o )(Q ,P1,P2,C ) is given by a more complicated function of the thermal Prandtl number P1, magnetic Prandtl number P2 and Cattaneo number C. To elucidate features of this dependence, we neglect P2 (in which case overstability would be classically forbidden), and thereby obtain an expression for the Rayleigh number that is far less strongly inhibited by the field, with limiting behaviour Rc(o )→π √{Q }/ C , as Q →∞ . One consequence of this weaker dependence is that onset of instability occurs as overstability provided C exceeds a threshold value CT(Q); indeed, crucially we show that when Q is large, CT∝1 / √{Q }, meaning that oscillatory modes are preferred even when C itself is small. Similar behaviour is demonstrated in the case of fixed boundaries by means of a novel numerical solution.
A hybrid type Ia supernova with an early flash triggered by helium-shell detonation.
Jiang, Ji-An; Doi, Mamoru; Maeda, Keiichi; Shigeyama, Toshikazu; Nomoto, Ken'ichi; Yasuda, Naoki; Jha, Saurabh W; Tanaka, Masaomi; Morokuma, Tomoki; Tominaga, Nozomu; Ivezić, Željko; Ruiz-Lapuente, Pilar; Stritzinger, Maximilian D; Mazzali, Paolo A; Ashall, Christopher; Mould, Jeremy; Baade, Dietrich; Suzuki, Nao; Connolly, Andrew J; Patat, Ferdinando; Wang, Lifan; Yoachim, Peter; Jones, David; Furusawa, Hisanori; Miyazaki, Satoshi
2017-10-04
Type Ia supernovae arise from the thermonuclear explosion of white-dwarf stars that have cores of carbon and oxygen. The uniformity of their light curves makes these supernovae powerful cosmological distance indicators, but there have long been debates about exactly how their explosion is triggered and what kind of companion stars are involved. For example, the recent detection of the early ultraviolet pulse of a peculiar, subluminous type Ia supernova has been claimed as evidence for an interaction between a red-giant or a main-sequence companion and ejecta from a white-dwarf explosion. Here we report observations of a prominent but red optical flash that appears about half a day after the explosion of a type Ia supernova. This supernova shows hybrid features of different supernova subclasses, namely a light curve that is typical of normal-brightness supernovae, but with strong titanium absorption, which is commonly seen in the spectra of subluminous ones. We argue that this early flash does not occur through previously suggested mechanisms such as the companion-ejecta interaction. Instead, our simulations show that it could occur through detonation of a thin helium shell either on a near-Chandrasekhar-mass white dwarf, or on a sub-Chandrasekhar-mass white dwarf merging with a less-massive white dwarf. Our finding provides evidence that one branch of previously proposed explosion models-the helium-ignition branch-does exist in nature, and that such a model may account for the explosions of white dwarfs in a mass range wider than previously supposed.
Gesammelte Werke / Collected Works
NASA Astrophysics Data System (ADS)
Schwarzschild, Karl; Voigt, Hans-Heinrich
Der bekannte Astronom Karl Schwarzschild (1873-1916) gilt als der Begründer der Astrophysik und als hervorragender Forscher mit einer erstaunlichen Bandbreite seiner Interessen. Arbeiten zur Himmelsmechanik, Elektrodynamik und Relativitätstheorie weisen ihn als vorzüglichen Mathematiker und Physiker auf der Höhe seiner Zeit aus. Untersuchungen zur Photographischen Photometrie, Optik und Spektroskopie zeigen den versierten Beobachter, der sein Meßinstrumentarium beherrscht, und schließlich arbeitete Schwarzschild als Astrophysiker an Sternatmosphären, Kometen, Struktur und Dynamik von Sternsystemen. Die in seinem kurzen Leben entstandene Fülle an wissenschaftlichen Arbeiten ist in drei Bänden der Gesamtausgabe gesammelt, ergänzt durch biographisches Material, Annotationen von Fachleuten und einen Essay des Nobelpreisträgers S. Chandrasekhar. The well-known astronomer Karl Schwarzschild (1873-1916) is regarded as the founder of astrophysics and as an exceptionally talented researcher whose interests spanned a remarkably broad spectrum. His work on celestial mechanics, electrodynamics, and relativity theory demonstrates his great abilities as a mathematician and physicist who significantly influenced the science of his times. His investigations of photographic photometry, optics, and spectroscopy display his strengths as an observer who knew his instruments. But above all Schwarzschild pursued questions of astrophysics, addressing in particular stellar atmospheres, comets, and the structure and dynamics of stellar systems. The host of scientific works that he authored in his short life is now collected in the form of this three-volume complete works; it is supplemented by biographical material, notes from some of todays experts, and an essay by the Nobel Laureate S. Chandrasekhar.
NASA Astrophysics Data System (ADS)
Maguire, K.; Sim, S. A.; Shingles, L.; Spyromilio, J.; Jerkstrand, A.; Sullivan, M.; Chen, T.-W.; Cartier, R.; Dimitriadis, G.; Frohmaier, C.; Galbany, L.; Gutiérrez, C. P.; Hosseinzadeh, G.; Howell, D. A.; Inserra, C.; Rudy, R.; Sollerman, J.
2018-03-01
The late-time spectra of Type Ia supernovae (SNe Ia) are powerful probes of the underlying physics of their explosions. We investigate the late-time optical and near-infrared spectra of seven SNe Ia obtained at the VLT with XShooter at >200 d after explosion. At these epochs, the inner Fe-rich ejecta can be studied. We use a line-fitting analysis to determine the relative line fluxes, velocity shifts, and line widths of prominent features contributing to the spectra ([Fe II], [Ni II], and [Co III]). By focussing on [Fe II] and [Ni II] emission lines in the ˜7000-7500 Å region of the spectrum, we find that the ratio of stable [Ni II] to mainly radioactively-produced [Fe II] for most SNe Ia in the sample is consistent with Chandrasekhar-mass delayed-detonation explosion models, as well as sub-Chandrasekhar mass explosions that have metallicity values above solar. The mean measured Ni/Fe abundance of our sample is consistent with the solar value. The more highly ionised [Co III] emission lines are found to be more centrally located in the ejecta and have broader lines than the [Fe II] and [Ni II] features. Our analysis also strengthens previous results that SNe Ia with higher Si II velocities at maximum light preferentially display blueshifted [Fe II] 7155 Å lines at late times. Our combined results lead us to speculate that the majority of normal SN Ia explosions produce ejecta distributions that deviate significantly from spherical symmetry.
NASA Technical Reports Server (NTRS)
Weng, Fuzhong
1992-01-01
A theory is developed for discretizing the vector integro-differential radiative transfer equation including both solar and thermal radiation. A complete solution and boundary equations are obtained using the discrete-ordinate method. An efficient numerical procedure is presented for calculating the phase matrix and achieving computational stability. With natural light used as a beam source, the Stokes parameters from the model proposed here are compared with the analytical solutions of Chandrasekhar (1960) for a Rayleigh scattering atmosphere. The model is then applied to microwave frequencies with a thermal source, and the brightness temperatures are compared with those from Stamnes'(1988) radiative transfer model.
Constraints on the invariant functions of axisymmetric turbulence
NASA Technical Reports Server (NTRS)
Kerschen, E. J.
1983-01-01
Constraints are derived for the two invariant functions Q1 and Q2 that occur in Chandrasekhar's (1950) development of the axisymmetric turbulence theory. These constraints must be satisfied for the correlation tensor derived from Q1 and Q2 to be that of a stationary random process, i.e., for the turbulence to be realizable. The equivalent results in spectrum space are also developed. Applications of the constraints in aerodynamic noise modeling are discussed. It is shown that significant errors in prediction can be introduced by the use of turbulence models which violate the constraints.
Recycling Matter in the Universe. X-Ray observations of SBS1150+599A (PN 6135.9+55.9)
NASA Technical Reports Server (NTRS)
Tovmassian, Gagik; Tomsick, John; Napiwotzki, Ralf; Yungelson, Lev; Stasinska, Grazyna; Pena, Miriam; Richer, Michael
2008-01-01
We present X-ray observations of the close binary nucleus of the planetary nebula SBS 1150+599A obtained with the XMM-Newton satellite. Only one component of the binary can be observed in optical-UV. New X-ray observations show that the previously invisible component is a very hot compact star. This finding allows us to deduce rough values for the basic parameters of the binary. With a high probability the total mass of the system exceeds Chandrasekhar limit and makes the SBS1150+599A one of the best candidate for a supernova type Ia progenitor.
Origin of excess low-energy states in a disordered superconductor in a Zeeman field.
Loh, Y L; Trivedi, N; Xiong, Y M; Adams, P W; Catelani, G
2011-08-05
Tunneling density of states measurements of disordered superconducting Al films in high Zeeman fields reveal a significant population of subgap states which cannot be explained by standard BCS theory. We provide a natural explanation of these excess states in terms of a novel disordered Larkin-Ovchinnikov phase that occurs near the spin-paramagnetic transition at the Chandrasekhar-Clogston critical field. The disordered Larkin-Ovchinnikov superconductor is characterized by a pairing amplitude that changes sign at domain walls. These domain walls carry magnetization and support Andreev bound states that lead to distinct spectral signatures at low energy.
The Changing Nature of QU Carinae: SN Ia Progenitor or a Hoax?
NASA Astrophysics Data System (ADS)
Kafka, Stella
2013-01-01
The race to the elusive Type Ia supernovae (SNe Ia) progenitors is at its zenith, with numerous clues from SNe Ia ejecta and a dearth of observational candidates. Still, the single degenerate channel is a viable route of mass accumulation onto a white dwarf to the Chandrasekhar limit. I present long-term high resolution spectroscopy of QU Carinae, one of the most promising single degenerate SNe Ia progenitors. I discuss its highly variable nature and compare it to current scenarios for mass accumulation onto high-mass white dwarfs, eventually leading to WD detonation and to a supernova explosion.
Feng, Li; Gong, Jing; Jin, Zhen-yi; Li, Ning; Sun, Li-ping; Wu, Yi-ling; Pu, Jie-lin
2009-07-05
Shen song Yang xin (SSYX) is a compound of Chinese medicine with the effect of increasing heart rate (HR). This study aimed to evaluate its electrophysiological properties at heart and cellular levels. The Chinese miniature swines were randomly assigned to two groups, administered with SSYX or placebo for 4 weeks (n = 8 per group). Cardiac electrophysiological study (EPS) was performed before and after drug administration. The guinea pig ventricular myocytes were enzymatically isolated and whole cell voltage-clamp technique was used to evaluate the effect of SSYX on cardiac action potential (AP). SSYX treatment accelerated the HR from (141.8 +/- 36.0) beats per minute to (163.0 +/- 38.0) beats per minute (P = 0.013) without changing the other parameters in surface electrocardiogram. After blockage of the autonomic nervous system with metoprolol and atropin, SSYX had no effect on intrinsic HR (IHR), but decreased corrected sinus node recovery time (CSNRT) and sinus atrium conducting time (SACT). Intra cardiac EPS showed that SSYX significantly decreased the A-H and A-V intervals as well as shortened the atrial (A), atrioventricular node (AVN) and ventricular (V) effective refractory period (ERP). In isolated guinea pig ventricular myocytes, the most obvious effect of SSYX on action potential was a shortening of the action potential duration (APD) without change in shape of action potential. The shortening rates of APD(30), APD(50) and APD(90) were 19.5%, 17.8% and 15.3%, respectively. The resting potential (Em) and the interval between the end of APD(30) and APD(90) did not significantly change. The present study demonstrates that SSYX increases the HR and enhances the conducting capacity of the heart in the condition of the intact autonomic nervous system. SSYX homogenously decreases the ERP of the heart and shortens the APD of the myocytes, suggesting its antiarrhythmic effect without proarrhythmia.
Yang, Jin-Hua; Toda, Masanori J.; Suwito, Awit; Hashim, Rosli; Gao, Jian-Jun
2017-01-01
Abstract The genus Dichaetophora Duda comprises 61 described species classified into four species groups: agbo, tenuicauda, acutissima and sinensis. This genus is distributed exclusively in the Old World, and is rich in species in the tropical and subtropical areas of the Oriental, Australasian, and Afrotropical regions. In this paper, a new species group, the trilobita group, is established for six new species discovered from the Oriental region. The delimitation of these species is firstly performed in light of morphology and further with the aid of DNA sequences of the mitochondrial COI and COII (cytochrome c oxydase, subunits I and II, respectively) genes, considering also their respective geographical origins. Then, the new species (trilobita Yang & Gao, sp. n., heterochroma Yang & Gao, sp. n., flatosternata Yang & Gao, sp. n., borneoensis Yang & Gao, sp. n., javaensis Yang & Gao, sp. n., and sumatraensis Yang & Gao, sp. n.) are described, and a key, based on not only morphological but also molecular information, is provided. PMID:28769630
Jiang, Hai-Qiang; Li, Yun-Lun; Xie, Jun
2012-03-01
To study the changes of urine metabolites in hypertension patients of ascendant hyperactivity of Gan yang syndrome (AHGYS), and to explore its essence in hypertension patients. Ten typical hypertension patients of AHGYS were recruited as the patient group, and the other twelve healthy volunteers were recruited as the normal group. The metabolite profiling in the urine were collected using by high performance liquid chromatography coupled with time of flight mass spectrometry (HPLC-TOFMS). The principal component analysis (PCA) and partial least-square discriminant analysis (PLS-DA) were analyzed using SIMCA-P Software. The differential metabolites in the urine were found out and identified. The possible relevant metabolic pathways were explained. The data from the analysis by PCA in the urine samples of the patient group and the normal group showed, two sets of data could be obviously classified in the score plot. Compared with the normal group, significant changes happened to the body metabolism in the patient group. The metabolites relevant to hypertension patients of AHGYS were determined using the PLS-DA. Fifteen compounds of the structure and metabolic pathways had been confirmed through inquiring KEGG Database, mainly including amino acids, free fatty acids, sphingosine, and so on. The hypertension patients of AHGYS were studied using HPLC-TOFMS combined with pattern recognition, thus finding out small molecular metabolic markers from the microscopic field, which was advantageous in probing the biological nature of Chinese medicine syndromes.
NASA Astrophysics Data System (ADS)
Bochicchio, Marco
2017-03-01
Yang-Mills (YM) theory and QCD are known to be renormalizable, but not ultraviolet (UV) finite, order by order, in perturbation theory. It is a fundamental question whether YM theory or QCD is UV finite, or only renormalizable, order by order, in the large-N 't Hooft or Veneziano expansions. We demonstrate that the renormalization group (RG) and asymptotic freedom imply that in 't Hooft large-N expansion the S matrix in YM theory is UV finite, while in both 't Hooft and Veneziano large-N expansions, the S matrix in confining massless QCD is renormalizable but not UV finite. By the same argument, the large-N N =1 supersymmetry (SUSY) YM S matrix is UV finite as well. Besides, we demonstrate that, in both 't Hooft and Veneziano large-N expansions, the correlators of local gauge-invariant operators, as opposed to the S matrix, are renormalizable but, in general, not UV finite, either in YM theory and N =1 SUSY YM theory or a fortiori in massless QCD. Moreover, we compute explicitly the counterterms that arise from renormalizing the 't Hooft and Veneziano expansions by deriving in confining massless QCD-like theories a low-energy theorem of the Novikov-Shifman-Vainshtein-Zakharov type that relates the log derivative with respect to the gauge coupling of a k -point correlator, or the log derivative with respect to the RG-invariant scale, to a (k +1 )-point correlator with the insertion of Tr F2 at zero momentum. Finally, we argue that similar results hold in the large-N limit of a vast class of confining massive QCD-like theories, provided a renormalization scheme exists—as, for example, MS ¯ —in which the beta function is not dependent on the masses. Specifically, in both 't Hooft and Veneziano large-N expansions, the S matrix in confining massive QCD and massive N =1 SUSY QCD is renormalizable but not UV finite.
Rayleigh-Bénard convection with uniform vertical magnetic field.
Basak, Arnab; Raveendran, Rohit; Kumar, Krishna
2014-09-01
We present the results of direct numerical simulations of Rayleigh-Bénard convection in the presence of a uniform vertical magnetic field near instability onset. We have done simulations in boxes with square as well as rectangular cross sections in the horizontal plane. We have considered the horizontal aspect ratio η=L(y)/L(x)=1 and 2. The onset of the primary and secondary instabilities are strongly suppressed in the presence of the vertical magnetic field for η=1. The Nusselt number Nu scales with the Rayleigh number Ra close to the primary instability as [{Ra-Ra(c)(Q)}/Ra(c)(Q)](0.91), where Ra(c)(Q) is the threshold for onset of stationary convection at a given value of the Chandrasekhar number Q. Nu also scales with Ra/Q as (Ra/Q)(μ). The exponent μ varies in the range 0.39≤μ≤0.57 for Ra/Q≥25. The primary instability is stationary as predicted by Chandrasekhar. The secondary instability is temporally periodic for Pr=0.1 but quasiperiodic for Pr=0.025 for moderate values of Q. Convective patterns for higher values of Ra consist of periodic, quasiperiodic, and chaotic wavy rolls above the onset of the secondary instability for η=1. In addition, stationary as well as time-dependent cross rolls are observed, as Ra is further raised. The ratio r(o)/Pr is independent of Q for smaller values of Q. The delay in the onset of the oscillatory instability is significantly reduced in a simulation box with η=2. We also observe inclined stationary rolls for smaller values of Q for η=2.
Discovery of the Closest Hot Subdwarf Binary with White Dwarf Companion
NASA Astrophysics Data System (ADS)
Geier, S.; Marsh, T. R.; Dunlap, B. H.; Barlow, B. N.; Schaffenroth, V.; Ziegerer, E.; Heber, U.; Kupfer, T.; Maxted, P. F. L.; Miszalski, B.; Shporer, A.; Telting, J. H.; Ostensen, R. H.; O'Toole, S. J.; Gänsicke, B. T.; Napiwotzki, R.
2013-01-01
We report the discovery of an extremely close, eclipsing binary system. A white dwarf is orbited by a core He-burning compact hot subdwarf star with a period as short as ≃ 0.04987 d making this system the most compact hot subdwarf binary discovered so far. The subdwarf will start to transfer helium-rich material on short timescales of less than 50 Myr. The ignition of He-burning at the surface may trigger carbon-burning in the core although the WD is less massive than the Chandrasekhar limit (> 0.74 M⊙) making this binary a possible progenitor candidate for a supernova type Ia event.
Nonvalidity of I-Love-Q Relations for Hot White Dwarf Stars
NASA Astrophysics Data System (ADS)
Boshkayev, K.; Quevedo, H.
2018-05-01
The equilibrium configurations of uniformly rotating white dwarfs at finite temperatures are investigated, exploiting the Chandrasekhar equation of state for different isothermal cores. The Hartle-Thorne formalism is applied to construct white dwarf configurations in the framework of Newtonian physics. The equations of structure are considered in the slow rotation approximation and all basic parameters of rotating hot white dwarfs are computed to test the so-called moment of inertia, tidal Love number and quadrupole moment (I-Love-Q) relations. It is shown that even within the same equation of state the I-Love-Q relations are not universal for white dwarfs at finite temperatures.
Polarized Light Reflected and Transmitted by Thick Rayleigh Scattering Atmospheres
NASA Astrophysics Data System (ADS)
Natraj, Vijay; Hovenier, J. W.
2012-03-01
Accurate values for the intensity and polarization of light reflected and transmitted by optically thick Rayleigh scattering atmospheres with a Lambert surface underneath are presented. A recently reported new method for solving integral equations describing Chandrasekhar's X- and Y-functions is used. The results have been validated using various tests and techniques, including the doubling-adding method, and are accurate to within one unit in the eighth decimal place. Tables are stored electronically and expected to be useful as benchmark results for the (exo)planetary science and astrophysics communities. Asymptotic expressions to obtain Stokes parameters for a thick layer from those of a semi-infinite atmosphere are also provided.
Holography for field theory solitons
NASA Astrophysics Data System (ADS)
Domokos, Sophia K.; Royston, Andrew B.
2017-07-01
We extend a well-known D-brane construction of the AdS/dCFT correspondence to non-abelian defects. We focus on the bulk side of the correspondence and show that there exists a regime of parameters in which the low-energy description consists of two approximately decoupled sectors. The two sectors are gravity in the ambient spacetime, and a six-dimensional supersymmetric Yang-Mills theory. The Yang-Mills theory is defined on a rigid AdS4 × S 2 background and admits sixteen supersymmetries. We also consider a one-parameter deformation that gives rise to a family of Yang-Mills theories on asymptotically AdS4 × S 2 spacetimes, which are invariant under eight supersymmetries. With future holographic applications in mind, we analyze the vacuum structure and perturbative spectrum of the Yang-Mills theory on AdS4 × S 2, as well as systems of BPS equations for finite-energy solitons. Finally, we demonstrate that the classical Yang-Mills theory has a consistent truncation on the two-sphere, resulting in maximally supersymmetric Yang-Mills on AdS4.
Xu, Weiwei; Meng, Xianjun; Zhu, Anning; Wang, Yu; Luo, Wuyougumo; Kuang, Zifang
2017-01-12
Professor ZHANG Yongshu , who studied from professor LIU Zhangjie , is a famous acupuncturist in Quanzhou of Southern Fujian. The publications authored by professor ZHANG Yongshu were collected in this study to summarize his academic characteristics of acupuncture and moxibustion. The result indicated he highly valued the regulation of yang qi , and established the theory of "developing yang to nourish yin ", which proposes to develop yang qi to achieve the effect of culturing yin ; he summarized eight methods to regulate the governor vessel and conception vessel, which can condition the body's yin and yang ; he paid attention to moxibustion therapy and its dosage, and made the best of direct moxibustion. In addition, he focused on meridian theory with effective application of meridian syndrome differentiation; in clinical treatment, he regulated the hand- yangming meridian to treat diseases by nourishing yang , generating yin and regulating fu .
Stimulus Law Revs up Research on Energy
ERIC Educational Resources Information Center
Basken, Paul
2009-01-01
When President Obama dreams out loud, as he did in a speech last week, of a future when solar panels are as "cheap as paint" and buildings produce their own energy, researchers like the physicist Yang Yang are dreaming right along with him. Mr. Yang's laboratory is among hundreds at colleges around the country that stand to benefit from a new…
Solar abundance ratios of the iron-peak elements in the Perseus cluster.
2017-11-23
The metal abundance of the hot plasma that permeates galaxy clusters represents the accumulation of heavy elements produced by billions of supernovae. Therefore, X-ray spectroscopy of the intracluster medium provides an opportunity to investigate the nature of supernova explosions integrated over cosmic time. In particular, the abundance of the iron-peak elements (chromium, manganese, iron and nickel) is key to understanding how the progenitors of typical type Ia supernovae evolve and explode. Recent X-ray studies of the intracluster medium found that the abundance ratios of these elements differ substantially from those seen in the Sun, suggesting differences between the nature of type Ia supernovae in the clusters and in the Milky Way. However, because the K-shell transition lines of chromium and manganese are weak and those of iron and nickel are very close in photon energy, high-resolution spectroscopy is required for an accurate determination of the abundances of these elements. Here we report observations of the Perseus cluster, with statistically significant detections of the resonance emission from chromium, manganese and nickel. Our measurements, combined with the latest atomic models, reveal that these elements have near-solar abundance ratios with respect to iron, in contrast to previous claims. Comparison between our results and modern nucleosynthesis calculations disfavours the hypothesis that type Ia supernova progenitors are exclusively white dwarfs with masses well below the Chandrasekhar limit (about 1.4 times the mass of the Sun). The observed abundance pattern of the iron-peak elements can be explained by taking into account a combination of near- and sub-Chandrasekhar-mass type Ia supernova systems, adding to the mounting evidence that both progenitor types make a substantial contribution to cosmic chemical enrichment.
Solar abundance ratios of the iron-peak elements in the Perseus cluster
Aharonian, Felix; Akamatsu, Hiroki; Akimoto, Fumie; ...
2017-11-13
The metal abundance of the hot plasma that permeates galaxy clusters represents the accumulation of heavy elements produced by billions of supernovae1. Therefore, X-ray spectroscopy of the intracluster medium provides an opportunity to investigate the nature of supernova explosions integrated over cosmic time. In particular, the abundance of the iron-peak elements (chromium, manganese, iron and nickel) is key to understanding how the progenitors of typical type Ia supernovae evolve and explode2–6. Recent X-ray studies of the intracluster medium found that the abundance ratios of these elements differ substantially from those seen in the Sun, suggesting differences between the nature ofmore » type Ia supernovae in the clusters and in the Milky Way. However, because the K-shell transition lines of chromium and manganese are weak and those of iron and nickel are very close in photon energy, highresolution spectroscopy is required for an accurate determination of the abundances of these elements. Here in this paper we report observations of the Perseus cluster, with statistically significant detections of the resonance emission from chromium, manganese and nickel. Our measurements, combined with the latest atomic models, reveal that these elements have near-solar abundance ratios with respect to iron, in contrast to previous claims. Comparison between our results and modern nucleosynthesis calculations disfavours the hypothesis that type Ia supernova progenitors are exclusively white dwarfs with masses well below the Chandrasekhar limit (about 1.4 times the mass of the Sun). The observed abundance pattern of the iron-peak elements can be explained by taking into account a combination of near- and sub-Chandrasekhar-mass type Ia supernova systems, adding to the mounting evidence that both progenitor types make a substantial contribution to cosmic chemical enrichment.« less
White Dwarf/M Dwarf Binaries as Single Degenerate Progenitors of Type Ia Supernovae
NASA Astrophysics Data System (ADS)
Wheeler, J. Craig
2012-10-01
Limits on the companions of white dwarfs in the single-degenerate scenario for the origin of Type Ia supernovae (SNe Ia) have gotten increasingly tight, yet igniting a nearly Chandrasekhar mass C/O white dwarf from a condition of near hydrostatic equilibrium provides compelling agreement with observed spectral evolution. The only type of non-degenerate stars that survive the tight limits, MV >~ 8.4 on the SN Ia in SNR 0509-67.5 and MV >~ 9.5 in the remnant of SN 1572, are M dwarfs. While M dwarfs are observed in cataclysmic variables, they have special properties that have not been considered in most work on the progenitors of SNe Ia: they have small but finite magnetic fields and they flare frequently. These properties are explored in the context of SN Ia progenitors. White dwarf/M dwarf pairs may be sufficiently plentiful to provide, in principle, an adequate rate of explosions even with slow orbital evolution due to magnetic braking or gravitational radiation. Even modest magnetic fields on the white dwarf and M dwarf will yield adequate torques to lock the two stars together, resulting in a slowly rotating white dwarf, with the magnetic poles pointing at one another in the orbital plane. The mass loss will be channeled by a "magnetic bottle" connecting the two stars, landing on a concentrated polar area on the white dwarf. This enhances the effective rate of accretion compared to spherical accretion. Luminosity from accretion and hydrogen burning on the surface of the white dwarf may induce self-excited mass transfer. The combined effects of self-excited mass loss, polar accretion, and magnetic inhibition of mixing of accretion layers give possible means to beat the "nova limit" and grow the white dwarf to the Chandrasekhar mass even at rather moderate mass accretion rates.
Solar abundance ratios of the iron-peak elements in the Perseus cluster
DOE Office of Scientific and Technical Information (OSTI.GOV)
Aharonian, Felix; Akamatsu, Hiroki; Akimoto, Fumie
The metal abundance of the hot plasma that permeates galaxy clusters represents the accumulation of heavy elements produced by billions of supernovae1. Therefore, X-ray spectroscopy of the intracluster medium provides an opportunity to investigate the nature of supernova explosions integrated over cosmic time. In particular, the abundance of the iron-peak elements (chromium, manganese, iron and nickel) is key to understanding how the progenitors of typical type Ia supernovae evolve and explode2–6. Recent X-ray studies of the intracluster medium found that the abundance ratios of these elements differ substantially from those seen in the Sun, suggesting differences between the nature ofmore » type Ia supernovae in the clusters and in the Milky Way. However, because the K-shell transition lines of chromium and manganese are weak and those of iron and nickel are very close in photon energy, highresolution spectroscopy is required for an accurate determination of the abundances of these elements. Here in this paper we report observations of the Perseus cluster, with statistically significant detections of the resonance emission from chromium, manganese and nickel. Our measurements, combined with the latest atomic models, reveal that these elements have near-solar abundance ratios with respect to iron, in contrast to previous claims. Comparison between our results and modern nucleosynthesis calculations disfavours the hypothesis that type Ia supernova progenitors are exclusively white dwarfs with masses well below the Chandrasekhar limit (about 1.4 times the mass of the Sun). The observed abundance pattern of the iron-peak elements can be explained by taking into account a combination of near- and sub-Chandrasekhar-mass type Ia supernova systems, adding to the mounting evidence that both progenitor types make a substantial contribution to cosmic chemical enrichment.« less
NASA Technical Reports Server (NTRS)
1999-01-01
The primary objective of the STS-93 mission was to deploy the Advanced X-ray Astrophysical Facility, which had been renamed the Chandra X-ray Observatory in honor of the late Indian-American Nobel Laureate Subrahmanyan Chandrasekhar. The mission was launched at 12:31 on July 23, 1999 onboard the space shuttle Columbia. The mission was led by Commander Eileen Collins. The crew was Pilot Jeff Ashby and Mission Specialists Cady Coleman, Steve Hawley and Michel Tognini from the Centre National d'Etudes Spatiales (CNES). This videotape shows the astronauts arrival at Kennedy Space Center a week before the launch. Each of the astronauts gives brief remarks, beginning with Eileen Collins, the first woman to command a space mission.
NASA Technical Reports Server (NTRS)
Banks, H. T.; Ito, K.
1991-01-01
A hybrid method for computing the feedback gains in linear quadratic regulator problem is proposed. The method, which combines use of a Chandrasekhar type system with an iteration of the Newton-Kleinman form with variable acceleration parameter Smith schemes, is formulated to efficiently compute directly the feedback gains rather than solutions of an associated Riccati equation. The hybrid method is particularly appropriate when used with large dimensional systems such as those arising in approximating infinite-dimensional (distributed parameter) control systems (e.g., those governed by delay-differential and partial differential equations). Computational advantages of the proposed algorithm over the standard eigenvector (Potter, Laub-Schur) based techniques are discussed, and numerical evidence of the efficacy of these ideas is presented.
Probabilistic Fretting Fatigue Life Prediction of Ti-6Al-4V (PREPRINT)
2010-01-01
Ceramics & NDE Division Harry R. Millwater and Xiaobin Yang University of Texas at San Antonio JANUARY 2010 Approved for...Patrick J. Golden (AFRL/RXLM) Harry R. Millwater and Xiaobin Yang (University of Texas at San Antonio) 5d. PROJECT NUMBER 4347 5e. TASK NUMBER...Patterson AFB, OH 45433, USA Harry R. Millwater and Xiaobin Yang University of Texas at San Antonio, San Antonio, TX 78249, USA Abstract A
Kakizaki, Fumihiko; Sonoshita, Masahiro; Miyoshi, Hiroyuki; Itatani, Yoshiro; Ito, Shinji; Kawada, Kenji; Sakai, Yoshiharu; Taketo, M Mark
2016-11-01
We recently found that the product of the AES gene functions as a metastasis suppressor of colorectal cancer (CRC) in both humans and mice. Expression of amino-terminal enhancer of split (AES) protein is significantly decreased in liver metastatic lesions compared with primary colon tumors. To investigate its downregulation mechanism in metastases, we searched for transcriptional regulators of AES in human CRC and found that its expression is reduced mainly by transcriptional dysregulation and, in some cases, by additional haploidization of its coding gene. The AES promoter-enhancer is in a typical CpG island, and contains a Yin-Yang transcription factor recognition sequence (YY element). In human epithelial cells of normal colon and primary tumors, transcription factor YY2, a member of the YY family, binds directly to the YY element, and stimulates expression of AES. In a transplantation mouse model of liver metastases, however, expression of Yy2 (and therefore of Aes) is downregulated. In human CRC metastases to the liver, the levels of AES protein are correlated with those of YY2. In addition, we noticed copy-number reduction for the AES coding gene in chromosome 19p13.3 in 12% (5/42) of human CRC cell lines. We excluded other mechanisms such as point or indel mutations in the coding or regulatory regions of the AES gene, CpG methylation in the AES promoter enhancer, expression of microRNAs, and chromatin histone modifications. These results indicate that Aes may belong to a novel family of metastasis suppressors with a CpG-island promoter enhancer, and it is regulated transcriptionally. © 2016 The Authors. Cancer Science published by John Wiley & Sons Australia, Ltd on behalf of Japanese Cancer Association.
Linear-response time-dependent density-functional theory with pairing fields.
Peng, Degao; van Aggelen, Helen; Yang, Yang; Yang, Weitao
2014-05-14
Recent development in particle-particle random phase approximation (pp-RPA) broadens the perspective on ground state correlation energies [H. van Aggelen, Y. Yang, and W. Yang, Phys. Rev. A 88, 030501 (2013), Y. Yang, H. van Aggelen, S. N. Steinmann, D. Peng, and W. Yang, J. Chem. Phys. 139, 174110 (2013); D. Peng, S. N. Steinmann, H. van Aggelen, and W. Yang, J. Chem. Phys. 139, 104112 (2013)] and N ± 2 excitation energies [Y. Yang, H. van Aggelen, and W. Yang, J. Chem. Phys. 139, 224105 (2013)]. So far Hartree-Fock and approximated density-functional orbitals have been utilized to evaluate the pp-RPA equation. In this paper, to further explore the fundamentals and the potential use of pairing matrix dependent functionals, we present the linear-response time-dependent density-functional theory with pairing fields with both adiabatic and frequency-dependent kernels. This theory is related to the density-functional theory and time-dependent density-functional theory for superconductors, but is applied to normal non-superconducting systems for our purpose. Due to the lack of the proof of the one-to-one mapping between the pairing matrix and the pairing field for time-dependent systems, the linear-response theory is established based on the representability assumption of the pairing matrix. The linear response theory justifies the use of approximated density-functionals in the pp-RPA equation. This work sets the fundamentals for future density-functional development to enhance the description of ground state correlation energies and N ± 2 excitation energies.
The peculiar Type Ia supernova iPTF14atg: Chandrasekhar-mass explosion or violent merger?
NASA Astrophysics Data System (ADS)
Kromer, M.; Fremling, C.; Pakmor, R.; Taubenberger, S.; Amanullah, R.; Cenko, S. B.; Fransson, C.; Goobar, A.; Leloudas, G.; Taddia, F.; Röpke, F. K.; Seitenzahl, I. R.; Sim, S. A.; Sollerman, J.
2016-07-01
iPTF14atg, a subluminous peculiar Type Ia supernova (SN Ia) similar to SN 2002es, is the first SN Ia for which a strong UV flash was observed in the early-time light curves. This has been interpreted as evidence for a single-degenerate (SD) progenitor system, where such a signal is expected from interactions between the SN ejecta and the non-degenerate companion star. Here, we compare synthetic observables of multidimensional state-of-the-art explosion models for different progenitor scenarios to the light curves and spectra of iPTF14atg. From our models, we have difficulties explaining the spectral evolution of iPTF14atg within the SD progenitor channel. In contrast, we find that a violent merger of two carbon-oxygen white dwarfs with 0.9 and 0.76 M⊙, respectively, provides an excellent match to the spectral evolution of iPTF14atg from 10 d before to several weeks after maximum light. Our merger model does not naturally explain the initial UV flash of iPTF14atg. We discuss several possibilities like interactions of the SN ejecta with the circumstellar medium and surface radioactivity from an He-ignited merger that may be able to account for the early UV emission in violent merger models.
Combustion and Conversion Efficiency of Nanoaluminum-Water Mixtures
2008-12-01
Sabourin b, Vigor Yang b, Richard A. Yetter b, Steven F. Son c, and Bryce C. Tappan d a The Pennsylvania State University—Altoona, Altoona, PA, USA...smpp/title~content=t713456315 Combustion and Conversion Efficiency of Nanoaluminum-Water Mixtures Grant A. Risha a; Justin L. Sabourin b; Vigor Yang b...Online Publication Date: 01 December 2008 To cite this Article Risha, Grant A., Sabourin , Justin L., Yang, Vigor, Yetter, Richard A., Son, Steven F. and
Wilson loops in supersymmetric gauge theories
NASA Astrophysics Data System (ADS)
Pestun, Vasily
This thesis is devoted to several exact computations in four-dimensional supersymmetric gauge field theories. In the first part of the thesis we prove conjecture due to Erickson-Semenoff-Zarembo and Drukker-Gross which relates supersymmetric circular Wilson loop operators in the N = 4 supersymmetric Yang-Mills theory with a Gaussian matrix model. We also compute the partition function and give a new matrix model formula for the expectation value of a supersymmetric circular Wilson loop operator for the pure N = 2 and the N* = 2 supersymmetric Yang-Mills theory on a four-sphere. Circular supersymmetric Wilson loops in four-dimensional N = 2 superconformal gauge theory are treated similarly. In the second part we consider supersymmetric Wilson loops of arbitrary shape restricted to a two-dimensional sphere in the four-dimensional N = 4 supersymmetric Yang-Mills theory. We show that expectation value for these Wilson loops can be exactly computed using a two-dimensional theory closely related to the topological two-dimensional Higgs-Yang-Mills theory, or two-dimensional Yang-Mills theory for the complexified gauge group.
Sun, Jing; Dai, Yaohua; Zhang, Shuaiming; Huang, Jian; Yang, Zhenyu; Huo, Junsheng; Chen, Chunming
2011-10-01
In China, a full fat soy powder mixed with multiple micronutrient powders (Ying Yang Bao (YYB)) was developed, and the efficacy of YYB was shown in controlling anaemia and improving child growth and development. However, prior to 2008, there was no sustainable way to provide YYB to vulnerable populations, except through free distribution by the government. This study was to test the concept of public-private partnership (PPP) to deliver YYB and to evaluate the effectiveness of marketing YYB through PPP. Programme activities included development of a complementary food supplement (CFS) national standard, product concept test, product development and marketing, behavior change communication, monitoring and evaluation. Baseline and end-line surveys were used to evaluate product awareness, purchasing and the impacts of the project on anaemia and feeding practices. A Chinese CFS standard was approved. Caregivers and their 6- to-24-month-old children participated in the baseline (n=226) and the end-line survey (n=221). A concept test at the baseline survey showed that 78% of caregivers were willing to buy YYB at 0.1 USD. After developing the product and implementing the intervention for 8 months, 59.6% of surveyed caregivers purchased YYB. While not significant, the prevalence of anaemia was marginally lower at the end line (28.8%) than at the baseline (36.2%). For those purchasing YYB, the risk of anaemia was significantly reduced by 87% of odds (P<0.009). The end-line survey found that feeding practices had improved significantly following the intervention. An enabling policy and regulatory environment in which CFSs are defined and parameters for appropriate marketing are identified as a prerequisite for marketing YYB or other nutritious CFS. Public and private advocacy and marketing could successfully increase awareness of YYB and access and use through market channels. The YYB project may be effective for reducing anaemia and improving feeding practices. © 2011
Benchmarking quantum mechanical calculations with experimental NMR chemical shifts of 2-HADNT
NASA Astrophysics Data System (ADS)
Liu, Yuemin; Junk, Thomas; Liu, Yucheng; Tzeng, Nianfeng; Perkins, Richard
2015-04-01
In this study, both GIAO-DFT and GIAO-MP2 calculations of nuclear magnetic resonance (NMR) spectra were benchmarked with experimental chemical shifts. The experimental chemical shifts were determined experimentally for carbon-13 (C-13) of seven carbon atoms for the TNT degradation product 2-hydroxylamino-4,6-dinitrotoluene (2-HADNT). Quantum mechanics GIAO calculations were implemented using Becke-3-Lee-Yang-Parr (B3LYP) and other six hybrid DFT methods (Becke-1-Lee-Yang-Parr (B1LYP), Becke-half-and-half-Lee-Yang-Parr (BH and HLYP), Cohen-Handy-3-Lee-Yang-Parr (O3LYP), Coulomb-attenuating-B3LYP (CAM-B3LYP), modified-Perdew-Wang-91-Lee-Yang-Parr (mPW1LYP), and Xu-3-Lee-Yang-Parr (X3LYP)) which use the same correlation functional LYP. Calculation results showed that the GIAO-MP2 method gives the most accurate chemical shift values, and O3LYP method provides the best prediction of chemical shifts among the B3LYP and other five DFT methods. Three types of atomic partial charges, Mulliken (MK), electrostatic potential (ESP), and natural bond orbital (NBO), were also calculated using MP2/aug-cc-pVDZ method. A reasonable correlation was discovered between NBO partial charges and experimental chemical shifts of carbon-13 (C-13).
Federal Register 2010, 2011, 2012, 2013, 2014
2011-07-20
... preliminary intent to rescind the new shipper review (``NSR'') of Xiang Yang Automobile Bearing Co., Ltd... Rescind the New Shipper Review of Xiang Yang Automobile Bearing Co., Ltd. (``ZXY''), dated June 17, 2011...
2017-10-03
Physics of Solids, 78 (314-332). 2014. 6. C . X. Zhang, J . Z. Song, Q. D. Yang, “Periodic buckling patterns of graphene/hexagonal boron nitride...Mechanics, 139 (78-97), 2015. 9. Y. C . Gu, J . Jung, Q. D. Yang, and W. Q. Chen, “A New Stabilizing Method for Numerical Analyses with Severe...Local and Global Instability”, ASME Journal of Applied Mechanics, 82 (101010-1, -12), 2015 10. J . Jung, B. C . Do, and Q. D. Yang, “A-FEM for Arbitrary
Diagnosis of Plasma States in X-Ray Laser Experiments
1992-10-01
J e AD-A256 909 FOREIGN AEROSPACE SCIENCE AND TECHNOLOGY CENTER DTIC 4 OCT 2 6 1992’ DIAGNOSIS OF PLASMA STATES IN X-RAY LASER EXPERIMENTS by Yang ...0619-92 HUMAN TRANSLATION FASTC-ID(RS)T-0619-92 8 October 1992 DIAGNOSIS OF PLASMA STATES IN X-RAY LASER EXPERIMENTS By: Yang Shangjin, Cai Yuqin, Chunyu... Yang Shangjin, Cai Yuqin, and Chunyu Shutai China Academy of Engineering Physics Abstract At an LF-12 laser installation, an Nd glass laser of
Influence of I-ching (Yijing, or The Book Of Changes) on Chinese medicine, philosophy and science.
Lu, Dominic P
2013-01-01
I-Ching or Yi-Jing ([see text] also known as The Book of Changes) is the earliest classic in China. It simply explained the formation of the universe and the relationship of man to the universe. Most, if not all, branches of various knowledge, including traditional Chinese medicine, can be traced back its origin to this Book in which Fu Shi ([see text] 2852 B.C.) theorized how the universe was formed, through his keen observation of environment and orbits of sun, moon and stars. He used symbols to represent his views. The essence of I-Ching is basically the expression and function of Yang symbolized as "--" (from <---->) and Yin symbolized "- -" (from --><--), and [see text] Yin and Yang as interaction and circulation of Yang and Yin. Both Yin and Yang were derived from the same origin, Tai-Chi. Fu Shi believed Yin and Yang were the two opposite background force and energy that make the universe as what it is. Yang and Yin manifest in great variety of phenomena such as mind and body, masculine and feminine, sun and moon, hot and cold, heaven and earth, positive and negative electricity etc. The entire theory of Chinese medicine is based on the theories of Yin and Yang as well as that of 5 Element Cycles which are also related to the orderly arrangement of 8 trigrams ([see text]) by King Wen ([see text]1099-1050 B.C.). The 5 Elements Theory explains the "check and balance" mechanism created by the background force of Yin and Yang Qi and illustrated the relationships that are either strengthened or weakened by "acting and controlling" among the 5 elements. I-Ching has exerted profound influences on some well- known European philosophers and scientists, notably Leibnitz and Hegel. Between I-Ching and modern cosmology and the physics of sub-atomic particles, there are some basic theories in common.
Kristopher J. Abell; Leah S. Bauer; Deborah L. Miller; Jian J. Duan; Roy G. Van Driesche
2016-01-01
The emerald ash borer, Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), is an important invasive pest of ash (Fraxinus) trees in North America. Two larval parasitoid species, Tetrastichus planipennisi Yang (Hymenoptera: Eulophidae) and Spathius agrili Yang (Hymenoptera:...
NASA Astrophysics Data System (ADS)
Oze, C.; Kumarathilaka, P. R.; Indraratne, S.; Vithanage, M. S.
2015-12-01
Prasanna Kumarathilaka Chemical and Environmental Systems Modeling Research Group, National Institute of Fundamental Studies, Kandy, Sri LankaPerchlorate (ClO4-) concentrations as high as 1 Wt.% have been reported in Martian regolith. Perchlorate is a strong oxidizer capable of accelerating heavy and/or trace metal release into regolith/soil and reacting with organic matter/compounds (if present). Here, we assess interactions between perchlorate and an analogous Martian regolith (i.e., serpentine soil) to simulate and understand the fate of Mn, Ni and Co and organic carbon. Pre-characterized serpentine soil collected from Sri Lanka was used for this study. Incubation experiments were performed with three perchlorate concentrations (1, 0.75 and 0.5 w/w) and sequential and single extractions assessed solid phase metal fractionation in serpentine sediments after 3 weeks and 1 year, respectively. Additionally, total organic carbon (TOC) of the residues were analyzed. These experiments demonstrate a high release of Mn compared to Ni and Co. Metal concentrations in exchangeable and bioavailable fractions increased with increasing perchlorate concentrations. Exchangeable Ni, Mn and Co increased 5.9, 69.6 and 44.6% and bioavailable Ni, Mn and Co increased 5.5, 92.3 and 72.8%, respectively, after 1 year compared to 3 weeks. Additionally, TOC decreased with increasing perchlorate concentration. For example, TOC decreased by 14.3% after 1 year compared to a 3 week incubation period. Overall, this study confirms the accelerated release of metals and the removal of organic carbon with increasing perchlorate concentrations. Furthermore, this study illustrates how perchlorate may present additional challenges to current Martian life studies and the future human habitation of Mars.Prasanna Kumarathilaka Chemical and Environmental Systems Modeling Research Group, National Institute of Fundamental Studies, Kandy, Sri LankaPerchlorate (ClO4-) concentrations as high as 1 Wt.% have
The application of the principles of invariance to the radiative transfer equation in plant canopies
NASA Technical Reports Server (NTRS)
Ganapol, B. D.; Myneni, R. B.
1992-01-01
Solutions of the radiative transfer equation describing photon interactions with vegetation canopies are important in remote sensing since they provide the canopy reflectance distribution required in the interpretation of satellite acquired information. The general one-dimensional two-angle transport problem for a finite copy of arbitrary leaf angle distribution is considered. Analytical solutions are obtained in terms of generalized Chandrasekhar's X- and Y-functions by invoking the principles of invariance. A critical step in the formulation involves the decomposition of the integral of the scattering phase function into a product of known functions of the incident and scattered photon directions. Several simplified cases previously considered in the literature are derived from the generalized solution. Various symmetries obeyed by the scattering operator and reciprocity relations are formally proved.
A numerical algorithm for optimal feedback gains in high dimensional LQR problems
NASA Technical Reports Server (NTRS)
Banks, H. T.; Ito, K.
1986-01-01
A hybrid method for computing the feedback gains in linear quadratic regulator problems is proposed. The method, which combines the use of a Chandrasekhar type system with an iteration of the Newton-Kleinman form with variable acceleration parameter Smith schemes, is formulated so as to efficiently compute directly the feedback gains rather than solutions of an associated Riccati equation. The hybrid method is particularly appropriate when used with large dimensional systems such as those arising in approximating infinite dimensional (distributed parameter) control systems (e.g., those governed by delay-differential and partial differential equations). Computational advantage of the proposed algorithm over the standard eigenvector (Potter, Laub-Schur) based techniques are discussed and numerical evidence of the efficacy of our ideas presented.
STS-93 Crew Interview: Michel Tognini
NASA Technical Reports Server (NTRS)
1999-01-01
This NASA Johnson Space Center (JSC) video release presents a one-on-one interview with Mission Specialist 3, Michel Tognini (Col., French Air Force and Centre Nacional Etudes Spatiales (CNES) Astronaut). Subjects discussed include early influences that made Michel want to be a pilot and astronaut, his experience as a French military pilot and his flying history. Also discussed were French participation in building the International Space Station (ISS), the STS-93 primary mission objective, X-ray observation using the Advanced X-ray Astrophysics Facility (AXAF), and failure scenarios associated with AXAF deployment. The STS-93 mission objective was to deploy the Advanced X-ray Astrophysics Facility (AXAF), later renamed the Chandra X-Ray Observatory in honor of the late Indian-American Nobel Laureate Subrahmanyan Chandrasekhar.
I -Love- Q relations for white dwarf stars
NASA Astrophysics Data System (ADS)
Boshkayev, K.; Quevedo, H.; Zhami, B.
2017-02-01
We investigate the equilibrium configurations of uniformly rotating white dwarfs, using Chandrasekhar and Salpeter equations of state in the framework of Newtonian physics. The Hartle formalism is applied to integrate the field equation together with the hydrostatic equilibrium condition. We consider the equations of structure up to the second order in the angular velocity, and compute all basic parameters of rotating white dwarfs to test the so-called moment of inertia, rotational Love number, and quadrupole moment (I-Love-Q) relations. We found that the I-Love-Q relations are also valid for white dwarfs regardless of the equation of state and nuclear composition. In addition, we show that the moment of inertia, quadrupole moment, and eccentricity (I-Q-e) relations are valid as well.
Chen Ning Yang’s New Contributions After He Returned to Where He Started
NASA Astrophysics Data System (ADS)
Zhu, Bang-Fen
2018-01-01
Chen Ning Yang returned to Tsinghua University as a full professor in 2003. Regarding the fact that very few people know what Professor Yang has contributed to science and to China after his return, in this article new contributions of Chen Ning Yang are introduced as far as the author knows, including his leading role in China’s sciences, the research in statistical physics, the role in cultivating gifted students, his research in history of science, and all other aspects relating to China’s developments.
Anticommutative extension of the Adler map
NASA Astrophysics Data System (ADS)
Konstantinou-Rizos, S.; Mikhailov, A. V.
2016-07-01
We construct a noncommutative (Grassmann) extension of the well-known Adler Yang-Baxter map. It satisfies the Yang-Baxter equation, it is reversible and birational. Our extension preserves all the properties of the original map except the involutivity.
Wave Propagation in Second-order Nonlinear Piezoelectric Media
2011-09-01
the theory of invariants, from invariant polynomial constitutive relations, Yang and Batra (23) investigated the second-order theory for piezoelectric...29, 30). Several commonly used transformation are shown in table 1. Yang and Batra (31) used a set of transformations that are very different from... Yang /Batra (31) DA = JF−1Aa D̂a EA = JF −1 Aa Êa ΠA = JF −1 Aa P̂a Dorfmann/Ogden (29) DA = JF−1Aa D̂a EA = FaAÊa ΠA = JF −1 Aa P̂a Clayton (30) DA
International Aviation (Selected Articles)
1991-06-05
The Manufacturing Capabilities of the Shanghai Aviation Company Leap to a New Level, by Yang Xinbang Zhang Shiyuan , Zheng Huilin............9 Setting...international cooperation. 8 THE MANUFACTURING CAPABILITIES OF THE SHANGHAI AVIATION COMPANY LEAP TO A NEW LEVEL Yang Xinbang Zhang Shiyuan Zheng
Yang, Juan; Zhang, Sujiong; Li, Weihai
2017-03-05
The following two new species from Shiwandashan of Guangxi Zhuang Autonomous Region, China are described, Neoperla bicolor Yang, Zhang & Li, sp. nov. and N. muranyii Yang, Zhang & Li, sp. nov. The new species are compared with related congeners of their respective species subgroups.
NASA Astrophysics Data System (ADS)
Starrfield, Sumner; Bose, Maitrayee; Iliadis, Christian; Hix, William R.; José, Jordi; Hernanz, Margarita
2017-08-01
We have continued our studies of accretion onto white dwarfs by following the evolution of thermonuclear runaways (TNRs) on Carbon Oxygen (CO) white dwarfs. We have varied the mass of the white dwarf and the composition of the accreted material. We use the results of the multi-dimensional studies of TNRs in white dwarfs, accreting only Solar matter, which show that sufficient core material is dredged-up by the TNR and then ejected by the explosion to agree with the observations of the ejecta abundances. We have also found that the initial 12C abundance is inversely proportional to the amount of material accreted prior to the TNR. Therefore, we first accrete Solar material and follow the evolution until a TNR occurs. Because the 12C abundance is significantly smaller then if we had initially mixed the accreting gas with the carbon-oxygen core, more matter takes part in the explosion than if we had begun the evolution with the mixed composition. We then instantaneously switch the composition to a mixture with either 25% core material or 50% core material (plus accreted material) and follow the resulting evolution of the TNR. We use our 1D, Lagrangian, hydrodynamic code: NOVA. We report on the results of these new simulations and compare the ejecta abundances to those measured in pre-solar grains that are thought to arise from classical nova explosions. These results will also be compared to recent results with SHIVA (Josè and Hernanz). We find that there are some white dwarf masses where significantly less mass is ejected than accreted during the Classical Nova event and, therefore, the white dwarf is growing in mass as a result of the accretion and in spite of the resulting explosion.This work was supported in part by NASA under the Astrophysics Theory Program grant 14-ATP14-0007 and the U.S. DOE under Contract No. DE-FG02- 97ER41041. SS acknowledges partial support from NASA, NSF, and HST grants to ASU and WRH is supported by the U.S. Department of Energy, Office of Nuclear Physics. The results reported herein benefitted from collaborations and/or information exchange within NASA’s Nexus for Exoplanet System Science (NExSS) research coordination network sponsored by NASA’s Science Mission Directorate.
LI, YACHAN; LIANG, WENNA; LI, XIHAI; GAO, BIZHEN; GAN, HUIJUAN; YIN, LIANHUA; SHEN, JIANYING; KANG, JIE; DING, SHANSHAN; LIN, XUEJUAN; LIAO, LINGHONG; LI, CANDONG
2015-01-01
The aim of the present study was to investigate the underlying mechanism of the Kidney-Yang deficiency (KYD) pattern of osteoporosis in postmenopausal women of a certain age range by comparing the effect of serum from postmenopausal women with osteoporosis exhibiting the KYD pattern with that of serum from postmenopausal women without osteoporosis on bone formation in an hFOB 1.19 human osteoblastic cell line. A random selection of 30 female, postmenopausal volunteers aged 60–70 years, including 15 cases without osteoporosis and 15 cases with the KYD pattern of osteoporosis, were enrolled at the Physical Examination Center of the Second Affiliated Hospital of Fujian University of Traditional Chinese Medicine. Venous blood was extracted and the serum was separated. The hFOB 1.19 cells were treated with 10% KYD pattern-serum or control serum from postmenopausal women of the same age range without osteoporosis. It was found that the KYD pattern-serum significantly decreased the cell viability, activity of alkaline phosphatase and number of calcified nodules, as well as downregulated the expression of osteocalcin and osteoprotegerin (OPG) and upregulated that of receptor activator of nuclear factor κB ligand (RANKL) in the hFOB 1.19 cells. In addition, the present results showed that the concentrations of estradiol (E2), OPG and insulin-like factor-1 (IGF-1) in the KYD pattern-serum were lower than those in the control serum. In combination, these findings suggest that the downregulation of E2, OPG and IGF-1 in the KYD pattern-serum inhibits the OPG/RANKL system, leading to a decrease in bone formation in the hFOB 1.19 cells. This indicates that the alterations in E2, OPG and IGF-1 may account for the susceptibility of certain postmenopausal women to the KYD pattern of osteoporosis. PMID:26622445
A Self-Adaptive Energy-Efficient Framework for Large Unattended Wireless Sensor Networks
2014-11-06
Transactions on Vehicular Technology, (10 2011): 3919. doi: 10.1109/ TVT .2011.2166093 Miao Zhao, Yuanyuan Yang. Optimization-Based DistributedAlgorithms for...Networks, IEEE Transactions on Vehicular Technology, (05 2013): 0. doi: 10.1109/ TVT .2012.2229309 Miao Zhao, Ming Ma, Yuanyuan Yang. Applying
Extremal functions for singular Trudinger-Moser inequalities in the entire Euclidean space
NASA Astrophysics Data System (ADS)
Li, Xiaomeng; Yang, Yunyan
2018-04-01
In a previous work (Adimurthi and Yang, 2010 [2]), Adimurthi-Yang proved a singular Trudinger-Moser inequality in the entire Euclidean space RN (N ≥ 2). Precisely, if 0 ≤ β < 1 and 0 < γ ≤ 1 - β, then there holds for any τ > 0,
USDA-ARS?s Scientific Manuscript database
Emerald ash borer (EAB), Agrilus planipennis Fairmaire, is an important invasive pest of ash (Fraxinus) trees in North America. Two larval parasitoids, Tetrastichus planipennisi Yang and Spathius agrili Yang, and one egg parasitoid, Oobius agrili Zhang and Huang, were introduced into the United Sta...
Stability and instability of hydromagnetic Taylor-Couette flows
NASA Astrophysics Data System (ADS)
Rüdiger, Günther; Gellert, Marcus; Hollerbach, Rainer; Schultz, Manfred; Stefani, Frank
2018-04-01
Decades ago S. Lundquist, S. Chandrasekhar, P. H. Roberts and R. J. Tayler first posed questions about the stability of Taylor-Couette flows of conducting material under the influence of large-scale magnetic fields. These and many new questions can now be answered numerically where the nonlinear simulations even provide the instability-induced values of several transport coefficients. The cylindrical containers are axially unbounded and penetrated by magnetic background fields with axial and/or azimuthal components. The influence of the magnetic Prandtl number Pm on the onset of the instabilities is shown to be substantial. The potential flow subject to axial fields becomes unstable against axisymmetric perturbations for a certain supercritical value of the averaged Reynolds number Rm bar =√{ Re ṡ Rm } (with Re the Reynolds number of rotation, Rm its magnetic Reynolds number). Rotation profiles as flat as the quasi-Keplerian rotation law scale similarly but only for Pm ≫ 1 while for Pm ≪ 1 the instability instead sets in for supercritical Rm at an optimal value of the magnetic field. Among the considered instabilities of azimuthal fields, those of the Chandrasekhar-type, where the background field and the background flow have identical radial profiles, are particularly interesting. They are unstable against nonaxisymmetric perturbations if at least one of the diffusivities is non-zero. For Pm ≪ 1 the onset of the instability scales with Re while it scales with Rm bar for Pm ≫ 1. Even superrotation can be destabilized by azimuthal and current-free magnetic fields; this recently discovered nonaxisymmetric instability is of a double-diffusive character, thus excluding Pm = 1. It scales with Re for Pm → 0 and with Rm for Pm → ∞. The presented results allow the construction of several new experiments with liquid metals as the conducting fluid. Some of them are described here and their results will be discussed together with relevant diversifications of
The reflection for dense plant canopies from the one-angle radiative transfer equation
NASA Technical Reports Server (NTRS)
Ganapol, B. D.; Lawless, James G. (Technical Monitor)
1994-01-01
An essential component of remote sensing of vegetation canopies from satellites is fundamental understanding. Since passive remote is driven by photons, the modeling of photon interactions with vegetation is a basic building block in that understanding. Several such photon transport models have been developed during the past two decades and continue to be developed. Different approaches have been followed including monte carlo, radiosity methods, geometric shadowing, and radiative transfer. In general, each approach has application for canopies with specific attributes. This presentation concerns the application of radiative transfer to dense vegetation canopies in which the soil does not participate. The approach taken here is novel in that a consistent theory for photon transport for non-rotationally invariant leaf scattering is developed in a canopy with a general leaf angle distribution (LAD). The theory is limited to the one-angle approximation (azimuthally averaged radiance) and is based on Chandrasekhar's analytical theory. While such a model is admittedly only approximate, it does fulfill a unique function in our search for understanding. In particular, the model is simple in its construct yet contains the essential features of canopy architecture that are mainly responsible for observed responses. Thus, this model will not only be a predictive tool but also an educational one. The mathematical setting is the radiative transfer equation in a dense (semiinfinite) canopy. The leaf scattering phase function is assumed to be Lambertian with different reflectance and transmittance. In addition, abaxial and adaxial differentiation is allowed which effectively destroys optical reciprocity. The analytical solution for the canopy BRDF is obtained by manipulation of the integral transport equation (a la Chandrasekhar) for a general LAD. With discretization of the. leaf angle, the resulting set of integral equations are solved iteratively including an acceleration
Plausibility and the Theoreticians' Regress: Constructing the evolutionary fate of stars
NASA Astrophysics Data System (ADS)
Ipe, Alex Ike
2002-10-01
This project presents a case-study of a scientific controversy that occurred in theoretical astrophysics nearly seventy years ago following the conceptual discovery of a novel phenomenon relating to the evolution and structure of stellar matter, known as the limiting mass. The ensuing debate between the author of the finding, Subrahmanyan Chandrasekhar and his primary critic, Arthur Stanley Eddington, witnessed both scientists trying to convince one another, as well as the astrophysical community, that their respective positions on the issue was the correct one. Since there was no independent criterion—that is, no observational evidence—at the time of the dispute that could have been drawn upon to test the validity of the limiting mass concept, a logical, objective resolution to the controversy was not possible. In this respect, I argue that the dynamics of the Chandrasekhar-Eddington debate succinctly resonates with Kennefick's notion of the Theoreticians' Regress. However, whereas this model predicts that such a regress can be broken if both parties in a dispute come to agree on who was in error and collaborate on a calculation whose technical foundation can be agreed to, I argue that a more pragmatic path by which the Theoreticians' Regress is broken is when one side in a dispute is able to construct its argument as being more plausible than that of its opponent, and is so successful in doing so, that its opposition is subsequently forced to withdraw from the debate. In order to adequately deal with the construction of plausibility in the context of scientific controversies, I draw upon Harvey's Plausibility Model as well as Pickering's work on the role socio-cultural factors play in the resolution of intellectual disputes. It is believed that the ideas embedded in these social- relativist-constructivist perspectives provide the most parsimonious explanation as to the reasons for the genesis and ultimate closure of this particular scientific controversy.
On integrable boundaries in the 2 dimensional O(N) σ-models
NASA Astrophysics Data System (ADS)
Aniceto, Inês; Bajnok, Zoltán; Gombor, Tamás; Kim, Minkyoo; Palla, László
2017-09-01
We make an attempt to map the integrable boundary conditions for 2 dimensional non-linear O(N) σ-models. We do it at various levels: classically, by demanding the existence of infinitely many conserved local charges and also by constructing the double row transfer matrix from the Lax connection, which leads to the spectral curve formulation of the problem; at the quantum level, we describe the solutions of the boundary Yang-Baxter equation and derive the Bethe-Yang equations. We then show how to connect the thermodynamic limit of the boundary Bethe-Yang equations to the spectral curve.
Multiple lesion track structure model
NASA Technical Reports Server (NTRS)
Wilson, John W.; Cucinotta, Francis A.; Shinn, Judy L.
1992-01-01
A multilesion cell kinetic model is derived, and radiation kinetic coefficients are related to the Katz track structure model. The repair-related coefficients are determined from the delayed plating experiments of Yang et al. for the C3H10T1/2 cell system. The model agrees well with the x ray and heavy ion experiments of Yang et al. for the immediate plating, delaying plating, and fractionated exposure protocols employed by Yang. A study is made of the effects of target fragments in energetic proton exposures and of the repair-deficient target-fragment-induced lesions.
Kardos, P
2014-12-01
After 8 years the Global Initiative for Asthma (GINA) presented a fully revised report. In May 2014 the new GINA was published online [www.ginasthma.org]. On a live GINA Session at the European Respiratory Society (ERS) conference 2014 in Munich members of the board of directors and of the science committee presented the new contents, e.g. the GINA statement from page one, that GINA is "Not a guideline, but a practical approach to managing asthma in clinical practice"--was explicitly emphasized on the ERS. This may reflect a changing claim towards a more pragmatic attempt (but probably also the fear of liability). © Georg Thieme Verlag KG Stuttgart · New York.
Perron-Frobenius theorem on the superfluid transition of an ultracold Fermi gas
NASA Astrophysics Data System (ADS)
Sakumichi, Naoyuki; Kawakami, Norio; Ueda, Masahito
2014-05-01
The Perron-Frobenius theorem is applied to identify the superfluid transition of the BCS-BEC crossover based on a cluster expansion method of Lee and Yang. Here, the cluster expansion is a systematic expansion of the equation of state (EOS) in terms of the fugacity z = exp (βμ) as βpλ3 = 2 z +b2z2 +b3z3 + ⋯ , with inverse temperature β =(kB T) - 1 , chemical potential μ, pressure p, and thermal de Broglie length λ =(2 πℏβ / m) 1 / 2 . According to the method of Lee and Yang, EOS is expressed by the Lee-Yang graphs. A singularity of an infinite series of ladder-type Lee-Yang graphs is analyzed. We point out that the singularity is governed by the Perron-Frobenius eigenvalue of a certain primitive matrix which is defined in terms of the two-body cluster functions and the Fermi distribution functions. As a consequence, it is found that there exists a unique fugacity at the phase transition point, which implies that there is no fragmentation of Bose-Einstein condensates of dimers and Cooper pairs at the ladder-approximation level of Lee-Yang graphs. An application to a BEC of strongly bounded dimers is also made.
Michael D. Ulyshen; Jian J. Duan; Leah S. Bauer; Juli Gould; Phil Taylor; Dick Bean; Carol Holko; Roy Van Driesche
2011-01-01
Field-cage methods were developed to evaluate the abilities of Tetrastichus planipennisi Yang (Hymenoptera: Eulophidae) and Spathius agrili Yang (Hymenoptera: Braconidae), biocontrol agents of Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), to parasitize, develop and overwinter following three late-season releases at both a northern (Michigan) and a southern (...
Conditions for the existence of Kelvin-Helmholtz instability in a CME
NASA Astrophysics Data System (ADS)
Páez, Andrés; Jatenco-Pereira, Vera; Falceta-Gonçcalves, Diego; Opher, Merav
The presence of Kelvin-Helmholtz instability (KHI) in the sheaths of Coronal Mass Ejections (CMEs) has been proposed and observed by several authors in the literature. In the present work, we assume their existence and propose a method to constrain the local properties, like the CME magnetic field intensity for the development of KHI. We study a CME in the initiation phase interacting with the slow solar wind (Zone I) and with the fast solar wind (Zone II). Based on the theory of magnetic KHI proposed by Chandrasekhar (1961) we found the radial heliocentric interval for the KHI existence, in particular we constrain it with the CME magnetic field intensity. We conclude that KHI may exist in both CME Zones but it is perceived that Zone I is more appropriated for the KHI formation.
Kim, Chang-Jun; Lelej, Arkady S; Park, Bia; Lee, Jong-Wook
2016-04-11
Kozlov (1994) established a new parasitic proctotrupoid family, Renyxidae, for a single species, Renyxa incredibilis, from Primorskij Krai, in the Russian Far East. A new genus and species, Hsiufuropronia chaoi, was described from China, Beijing (Yang 1997) in the family Roproniidae. Lelej and Kozlov (1999) noticed that Renyxa was preoccupied and was initially used by Kurochkin and Slankis (1973) for a genus of flatworms (Cestoda: Litobothridae). According to Articles 39, 60 of the Code (ICZN 1999), the names of the genus and family were changed to Proctorenyxa Lelej & Kozlov, 1999 (Lelej & Kozlov 1999). He et al. (2002) transferred Hsiufuropronia from Roproniidae to Proctorenyxidae based on Yang's original description and illustrations, and synonymized Hsiufuropronia Yang under Proctorenyxa Lelej & Kozlov. Later, He and Xu (2015) proposed that the family name Proctorenyxidae should be replaced by Hsiufuroproniidae and the genera Proctonenyxa Lelej & Kozlov and Hsiufuropronia Yang should be separate. However, the replacement name Hsiufuroproniidae contradicts article 39 of the Code (ICZN 1999).