A L-Band Superstrate Lens Enhanced Antenna and Array for Tactical Operations

DTIC Science & Technology

2013-07-01

unlimited 13. SUPPLEMENTARY NOTES 14. ABSTRACT The design of a 1.2 GHz microstrip antenna utilizing a superstrate layer for gain enhancement is...CA, 92152-5001 sam.chieh@navy.mil Abstract—The design of a 1.2 GHz microstrip antenna utilizing a superstrate layer for gain enhancement is...realized. The microstrip patch antenna is a widely used antenna in this regime as it is light weight and is easily scalable for increased gains. It has

Hidden sector monopole, vector dark matter and dark radiation with Higgs portal

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baek, Seungwon; Ko, P.; Park, Wan-Il, E-mail: sbaek1560@gmail.com, E-mail: pko@kias.re.kr, E-mail: wipark@kias.re.kr

2014-10-01

We show that the 't Hooft-Polyakov monopole model in the hidden sector with Higgs portal interaction makes a viable dark matter model, where monopole and massive vector dark matter (VDM) are stable due to topological conservation and the unbroken subgroup U(1 {sub X}. We show that, even though observed CMB data requires the dark gauge coupling to be quite small, a right amount of VDM thermal relic can be obtained via s-channel resonant annihilation for the mass of VDM close to or smaller than the half of SM higgs mass, thanks to Higgs portal interaction. Monopole relic density turns outmore » to be several orders of magnitude smaller than the observed dark matter relic density. Direct detection experiments, particularly, the projected XENON1T experiment, may probe the parameter space where the dark Higgs is lighter than ∼< 50 GeV. In addition, the dark photon associated with the unbroken U(1 {sub X} contributes to the radiation energy density at present, giving Δ N{sub eff}{sup ν} ∼ 0.1 as the extra relativistic neutrino species.« less

Infinite tension limit of the pure spinor superstring

NASA Astrophysics Data System (ADS)

Berkovits, Nathan

2014-03-01

Mason and Skinner recently constructed a chiral infinite tension limit of the Ramond-Neveu-Schwarz superstring which was shown to compute the Cachazo-He-Yuan formulae for tree-level d = 10 Yang-Mills amplitudes and the NS-NS sector of tree-level d = 10 supergravity amplitudes. In this letter, their chiral infinite tension limit is generalized to the pure spinor superstring which computes a d = 10 superspace version of the Cachazo-He-Yuan formulae for tree-level d = 10 super-Yang-Mills and supergravity amplitudes.

Fabrication of nanocrystal ink based superstrate-type CuInS₂ thin film solar cells.

PubMed

Cho, Jin Woo; Park, Se Jin; Kim, Woong; Min, Byoung Koun

2012-07-05

A CuInS₂ (CIS) nanocrystal ink was applied to thin film solar cell devices with superstrate-type configuration. Monodispersed CIS nanocrystals were synthesized by a colloidal synthetic route and re-dispersed in toluene to form an ink. A spray method was used to coat CIS films onto conducting glass substrates. Prior to CIS film deposition, TiO₂ and CdS thin films were also prepared as a blocking layer and a buffer layer, respectively. We found that both a TiO₂ blocking layer and a CdS buffer layer are necessary to generate photoresponses in superstrate-type devices. The best power conversion efficiency (∼1.45%) was achieved by the CIS superstrate-type thin film solar cell device with 200 and 100 nm thick TiO₂ and CdS films, respectively.

SAR reduction using a single SRR superstrate for a dual-band antenna.

PubMed

Rosaline, Imaculate; Singaravelu, Raghavan

2017-01-01

A dual-band microstrip antenna operating at GSM 900 and GSM 1800 MHz is designed initially. Then a single split ring resonator (SRR) structure is used as a superstrate for this dual-band antenna. A circular current is induced in the SRR due to the perpendicular plane wave excitation, which in turn leads to an electric excitation coupled to the magnetic resonance. It also exhibits higher order excitations at 0.9 and 1.8 GHz which ultimately resulted in specific absorption rate (SAR) reduction of human head at both the designed frequencies of the antenna. The antenna and the SRR superstrate are printed on a 1.6 mm thick FR-4 substrate of dimension 59.6 × 49.6 mm 2 . Analysis of the SRR using the classic waveguide theory approach is discussed. Radiation pattern of the antenna in the presence of SRR superstrate and human head is also discussed. Prototype of the antenna along with the SRR superstrate is fabricated and measured for return loss and radiation pattern. Measurement results fairly agree with the simulated results. A human head phantom is utilized in the calculation of SAR.

Type II superstring field theory: geometric approach and operadic description

NASA Astrophysics Data System (ADS)

Jurčo, Branislav; Münster, Korbinian

2013-04-01

We outline the construction of type II superstring field theory leading to a geometric and algebraic BV master equation, analogous to Zwiebach's construction for the bosonic string. The construction uses the small Hilbert space. Elementary vertices of the non-polynomial action are described with the help of a properly formulated minimal area problem. They give rise to an infinite tower of superstring field products defining a {N} = 1 generalization of a loop homotopy Lie algebra, the genus zero part generalizing a homotopy Lie algebra. Finally, we give an operadic interpretation of the construction.

Yukawa couplings in superstring compactification. [in quantum gravity theory

NASA Technical Reports Server (NTRS)

Strominger, A.

1985-01-01

A topological formula is given for the entire tree-level contribution to the low-energy effective action of a Calabi-Yau superstring compactification. The constraints on proton lifetime in the Calabi-Yau compactification are discussed in detail.

Neutrinos from the terrestrial passage of supersymmetric dark-matter Q-balls

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kusenko, Alexander; Institute for the Physics and Mathematics of the Universe, University of Tokyo, Kashiwa, Chiba 277-8568; Shoemaker, Ian M.

2009-07-15

Supersymmetry implies that stable nontopological solitons, Q-balls, could form in the early universe and could make up all or part of dark matter. We show that the relic Q-balls passing through Earth can produce a detectable neutrino flux. The peculiar zenith angle dependence and a small annual modulation of this flux can be used as signatures of dark-matter Q-balls.

Inhomogeneous tensionless superstrings

NASA Astrophysics Data System (ADS)

Bagchi, Arjun; Banerjee, Aritra; Chakrabortty, Shankhadeep; Parekh, Pulastya

2018-02-01

We construct a novel tensionless limit of Superstring theory that realises the Inhomogeneous Super Galilean Conformal Algebra (SGCA I ) as the residual symmetry in the analogue of the conformal gauge, as opposed to previous constructions of the tensionless superstring, where a smaller symmetry algebra called the Homogeneous SGCA emerged as the residual gauge symmetry on the worldsheet. We obtain various features of the new tensionless theory intrinsically as well as from a systematic limit of the corresponding features of the tensile theory. We discuss why it is desirable and also natural to work with this new tensionless limit and the larger algebra.

Application of 3d Model of Cultural Relics in Virtual Restoration

NASA Astrophysics Data System (ADS)

Zhao, S.; Hou, M.; Hu, Y.; Zhao, Q.

2018-04-01

In the traditional cultural relics splicing process, in order to identify the correct spatial location of the cultural relics debris, experts need to manually splice the existing debris. The repeated contact between debris can easily cause secondary damage to the cultural relics. In this paper, the application process of 3D model of cultural relic in virtual restoration is put forward, and the relevant processes and ideas are verified with the example of Terracotta Warriors data. Through the combination of traditional cultural relics restoration methods and computer virtual reality technology, virtual restoration of high-precision 3D models of cultural relics can provide a scientific reference for virtual restoration, avoiding the secondary damage to the cultural relics caused by improper restoration. The efficiency and safety of the preservation and restoration of cultural relics have been improved.

Big bang nucleosynthesis, the CMB, and the origin of matter and space-time

NASA Astrophysics Data System (ADS)

Mathews, Grant J.; Gangopadhyay, Mayukh; Sasankan, Nishanth; Ichiki, Kiyotomo; Kajino, Toshitaka

2018-04-01

We summarize some applications of big bang nucleosythesis (BBN) and the cosmic microwave background (CMB) to constrain the first moments of the creation of matter in the universe. We review the basic elements of BBN and how it constraints physics of the radiation-dominated epoch. In particular, how the existence of higher dimensions impacts the cosmic expansion through the projection of curvature from the higher dimension in the "dark radiation" term. We summarize current constraints from BBN and the CMB on this brane-world dark radiation term. At the same time, the existence of extra dimensions during the earlier inflation impacts the tensor to scalar ratio and the running spectral index as measured in the CMB. We summarize how the constraints on inflation shift when embedded in higher dimensions. Finally, one expects that the universe was born out of a complicated multiverse landscape near the Planck time. In these moments the energy scale of superstrings was obtainable during the early moments of chaotic inflation. We summarize the quest for cosmological evidence of the birth of space-time out of the string theory landscape. We will explore the possibility that a superstring excitations may have made itself known via a coupling to the field of inflation. This may have left an imprint of "dips" in the power spectrum of temperature fluctuations in the cosmic microwave background. The identification of this particle as a superstring is possible because there may be evidence for different oscillator states of the same superstring that appear on different scales on the sky. It will be shown that from this imprint one can deduce the mass, number of oscillations, and coupling constant for the superstring. Although the evidence is marginal, this may constitute the first observation of a superstring in Nature.

Brane inflation and cosmic string tension in superstring theory

NASA Astrophysics Data System (ADS)

Firouzjahi, Hassan; Tye, S.-H. Henry

2005-03-01

In a simple reanalysis of the KKLMMT scenario, we argue that the slow roll condition in the D3-overline {D}3 -brane inflationary scenario in superstring theory requires no more than a moderate tuning. The cosmic string tension is very sensitive to the conformal coupling: with less fine-tuning, the cosmic string tension (as well as the ratio of tensor to scalar perturbation mode) increases rapidly and can easily saturate the present observational bound. In a multi-throat brane inflationary scenario, this feature substantially improves the chance of detecting and measuring the properties of the cosmic strings as a window to the superstring theory and our pre-inflationary universe.

Analytical Tools for Investigating and Modeling Agent-Based Systems

DTIC Science & Technology

2005-06-01

of Black Holes Cluster 10 : Juan M. Maldacena (1924), Journal of High Energy Physics Field theory models for tachyon and gauge field string dy...namics; Super-Poincare Invariant Superstring Field The- ory; Level Four Approximation to the Tachyon Potential in Superstring Field Theory; SO(32) Spinors

Exploration and implementation of ontology-based cultural relic knowledge map integration platform

NASA Astrophysics Data System (ADS)

Yang, Weiqiang; Dong, Yiqiang

2018-05-01

To help designers to better carry out creative design and improve the ability of searching traditional cultural relic information, the ontology-based knowledge map construction method was explored and an integrated platform for cultural relic knowledge map was developed. First of all, the construction method of the ontology of cultural relics was put forward, and the construction of the knowledge map of cultural relics was completed based on the constructed cultural relic otology. Then, a personalized semantic retrieval framework for creative design was proposed. Finally, the integrated platform of the knowledge map of cultural relics was designed and realized. The platform was divided into two parts. One was the foreground display system, which was used for designers to search and browse cultural relics. The other was the background management system, which was for cultural experts to manage cultural relics' knowledge. The research results showed that the platform designed could improve the retrieval ability of cultural relic information. To sum up, the platform can provide a good support for the designer's creative design.

Stable indications of relic gravitational waves in Wilkinson Microwave Anisotropy Probe data and forecasts for the Planck mission

NASA Astrophysics Data System (ADS)

Zhao, W.; Baskaran, D.; Grishchuk, L. P.

2009-10-01

The relic gravitational waves are the cleanest probe of the violent times in the very early history of the Universe. They are expected to leave signatures in the observed cosmic microwave background anisotropies. We significantly improved our previous analysis [W. Zhao, D. Baskaran, and L. P. Grishchuk, Phys. Rev. DPRVDAQ1550-7998 79, 023002 (2009)10.1103/PhysRevD.79.023002] of the 5-year WMAP TT and TE data at lower multipoles ℓ. This more general analysis returned essentially the same maximum likelihood result (unfortunately, surrounded by large remaining uncertainties): The relic gravitational waves are present and they are responsible for approximately 20% of the temperature quadrupole. We identify and discuss the reasons by which the contribution of gravitational waves can be overlooked in a data analysis. One of the reasons is a misleading reliance on data from very high multipoles ℓ and another a too narrow understanding of the problem as the search for B modes of polarization, rather than the detection of relic gravitational waves with the help of all correlation functions. Our analysis of WMAP5 data has led to the identification of a whole family of models characterized by relatively high values of the likelihood function. Using the Fisher matrix formalism we formulated forecasts for Planck mission in the context of this family of models. We explore in detail various “optimistic,” “pessimistic,” and “dream case” scenarios. We show that in some circumstances the B-mode detection may be very inconclusive, at the level of signal-to-noise ratio S/N=1.75, whereas a smarter data analysis can reveal the same gravitational wave signal at S/N=6.48. The final result is encouraging. Even under unfavorable conditions in terms of instrumental noises and foregrounds, the relic gravitational waves, if they are characterized by the maximum likelihood parameters that we found from WMAP5 data, will be detected by Planck at the level S/N=3.65.

Better Back Contacts for Solar Cells on Flexible Substrates

NASA Technical Reports Server (NTRS)

Woods, Lawrence M.; Ribelin, Rosine M.

2006-01-01

Improved low-resistance, semitransparent back contacts, and a method of fabricating them, have been developed for solar photovoltaic cells that are made from thin films of I-III-VI2 semiconductor materials on flexible, high-temperatureresistant polyimide substrates or superstrates. The innovative aspect of the present development lies in the extension, to polyimide substrates or superstrates, of a similar prior development of improved low-resistance, semitransparent back contacts for I-III-VI2 solar cells on glass substrates or superstrates. A cell incorporating this innovation can be used either as a stand-alone photovoltaic device or as part of a monolithic stack containing another photovoltaic device that utilizes light of longer wavelengths.

Unitarity limits on the mass and radius of dark matter particles

NASA Technical Reports Server (NTRS)

Griest, Kim; Kamionkowski, Marc

1989-01-01

Using partial wave unitarity and the observed density of the Universe, it is show that a stable elementary particle which was once in thermal equilibrium cannot have a mass greater than 340 TeV. An extended object which was once in thermal equilibrium cannot have a radius less than 7.5 x 10(exp -7) fm. A lower limit to the relic abundance of such particles is also found.

Discussion of impact of relics activation on protection and utilization approaches-take the old summer palace as an example

NASA Astrophysics Data System (ADS)

Xiaoqi, J.

2015-08-01

As the popularization of cultural relics and the rapid development of cultural tourism industry, a large number of cultural relic tourism resources goes into public eyes. Activation of relics has became an important way for tourist to contact and understand culture relics. The way of how to properly interpret the historical sense and cultural uniqueness to the masses of tourists in order to achieve social service functions of relic resources has always been research focal point of site protection and utilization, so nowadays it has important significance to protection and utilization of heritage resources in our country. From the point of activation of relics and based on the analysis of resource characteristic, the paper in depth discuss ways of activation of relics of the Old Summer Palace, in order to provide reference for sustainable development of sites tourism in China.

Research on Splicing Method of Digital Relic Fragment Model

NASA Astrophysics Data System (ADS)

Yan, X.; Hu, Y.; Hou, M.

2018-04-01

In the course of archaeological excavation, a large number of pieces of cultural relics were unearthed, and the restoration of these fragments was done manually by traditional arts and crafts experts. In this process, cultural relics experts often try to splice the existing cultural relics, and then use adhesive to stick together the fragments of correct location, which will cause irreversible secondary damage to cultural relics. In order to minimize such damage, the surveyors combine 3D laser scanning with computer technology, and use the method of establishing digital cultural relics fragments model to make virtual splicing of cultural relics. The 3D software on the common market can basically achieve the model translation and rotation, using this two functions can be achieved manually splicing between models, mosaic records after the completion of the specific location of each piece of fragments, so as to effectively reduce the damage to the relics had tried splicing process.

Four-qubit systems and dyonic black Hole-Black branes in superstring theory

NASA Astrophysics Data System (ADS)

Belhaj, A.; Bensed, M.; Benslimane, Z.; Sedra, M. B.; Segui, A.

Using dyonic solutions in the type IIA superstring theory on Calabi-Yau (CY) manifolds, we reconsider the study of black objects and quantum information theory using string/string duality in six dimensions. Concretely, we relate four-qubits with a stringy quaternionic moduli space of type IIA compactification associated with a dyonic black solution formed by black holes (BHs) and black 2-branes (B2B) carrying eight electric charges and eight magnetic charges. This connection is made by associating the cohomology classes of the heterotic superstring on T4 to four-qubit states. These states are interpreted in terms of such dyonic charges resulting from the quaternionic symmetric space SO(4,4) SO(4)×SO(4) corresponding to a N = 4 sigma model superpotential in two dimensions. The superpotential is considered as a functional depending on four quaternionic fields mapped to a class of Clifford algebras denoted as Cl0,4. A link between such an algebra and the cohomology classes of T4 in heterotic superstring theory is also given.

SCRMS: An RFID and Sensor Web-Enabled Smart Cultural Relics Management System

PubMed Central

Xiao, Changjiang; Chen, Nengcheng; Li, Dandan; Lv, You; Gong, Jianya

2016-01-01

Cultural relics represent national or even global resources of inestimable value. How to efficiently manage and preserve these cultural relics is a vitally important issue. To achieve this goal, this study proposed, designed, and implemented an RFID and Sensor Web–enabled smart cultural relics management system (SCRMS). In this system, active photovoltaic subtle energy-powered Radio Frequency Identification (RFID) is used for long-range contactless identification and lifecycle management of cultural relics during their storage and circulation. In addition, different types of ambient sensors are integrated with the RFID tags and deployed around cultural relics to monitor their environmental parameters, helping to ensure that they remain in good condition. An Android-based smart mobile application, as middleware, is used in collaboration with RFID readers to collect information and provide convenient management for the circulation of cultural relics. Moreover, multiple sensing techniques are taken advantage of simultaneously for preservation of cultural relics. The proposed system was successfully applied to a museum in the Yongding District, Fujian Province, China, demonstrating its feasibility and advantages for smart and efficient management and preservation of cultural relics. PMID:28042820

SCRMS: An RFID and Sensor Web-Enabled Smart Cultural Relics Management System.

PubMed

Xiao, Changjiang; Chen, Nengcheng; Li, Dandan; Lv, You; Gong, Jianya

2016-12-30

Cultural relics represent national or even global resources of inestimable value. How to efficiently manage and preserve these cultural relics is a vitally important issue. To achieve this goal, this study proposed, designed, and implemented an RFID and Sensor Web-enabled smart cultural relics management system (SCRMS). In this system, active photovoltaic subtle energy-powered Radio Frequency Identification (RFID) is used for long-range contactless identification and lifecycle management of cultural relics during their storage and circulation. In addition, different types of ambient sensors are integrated with the RFID tags and deployed around cultural relics to monitor their environmental parameters, helping to ensure that they remain in good condition. An Android-based smart mobile application, as middleware, is used in collaboration with RFID readers to collect information and provide convenient management for the circulation of cultural relics. Moreover, multiple sensing techniques are taken advantage of simultaneously for preservation of cultural relics. The proposed system was successfully applied to a museum in the Yongding District, Fujian Province, China, demonstrating its feasibility and advantages for smart and efficient management and preservation of cultural relics.

Analysis on the environment of cultural relic as tourist attraction--take Yungang Grottoes as an example

NASA Astrophysics Data System (ADS)

Xiangdong, Zhu; Jie, Bai

2018-03-01

Cultural relic resources are precious non-renewable resources and an important cornerstone for the development of cultural relic tourism. With the rapid development of tourism industry, the native environment of cultural relics is being squeezed constantly. Meanwhile, under the economic interests, cultural relic’s protection and heritage tourism contradictions continue to intensify. The present era which the architectural style is convergence, cultural relics protection is simplistic, restore historical sites blindly and other. In the historical process of economic development and the acceleration of new-type urbanization, the heritage industry faces the dual tasks and development challenges. As cultural relic protection workers, investigation of the utilization of cultural relic’s tourist attractions, investigation and analysis of the Yungang Grottoes, indicating cultural relics as a tourist attraction, not only to strengthen the protection of ontology, also should attach importance to the coordinated development of the protection of cultural relics and the utilization of tourism.

Relics in galaxy clusters at high radio frequencies

NASA Astrophysics Data System (ADS)

Kierdorf, M.; Beck, R.; Hoeft, M.; Klein, U.; van Weeren, R. J.; Forman, W. R.; Jones, C.

2017-04-01

Aims: We investigated the magnetic properties of radio relics located at the peripheries of galaxy clusters at high radio frequencies, where the emission is expected to be free of Faraday depolarization. The degree of polarization is a measure of the magnetic field compression and, hence, the Mach number. Polarization observations can also be used to confirm relic candidates. Methods: We observed three radio relics in galaxy clusters and one radio relic candidate at 4.85 and 8.35 GHz in total emission and linearly polarized emission with the Effelsberg 100-m telescope. In addition, we observed one radio relic candidate in X-rays with the Chandra telescope. We derived maps of polarization angle, polarization degree, and Faraday rotation measures. Results: The radio spectra of the integrated emission below 8.35 GHz can be well fitted by single power laws for all four relics. The flat spectra (spectral indices of 0.9 and 1.0) for the so-called Sausage relic in cluster CIZA J2242+53 and the so-called Toothbrush relic in cluster 1RXS 06+42 indicate that models describing the origin of relics have to include effects beyond the assumptions of diffuse shock acceleration. The spectra of the radio relics in ZwCl 0008+52 and in Abell 1612 are steep, as expected from weak shocks (Mach number ≈2.4). Polarization observations of radio relics offer a method of measuring the strength and geometry of the shock front. We find polarization degrees of more than 50% in the two prominent Mpc-sized radio relics, the Sausage and the Toothbrush, which are among the highest percentages of linear polarization detected in any extragalactic radio source to date. This is remarkable because the large beam size of the Effelsberg single-dish telescope corresponds to linear extensions of about 300 kpc at 8.35 GHz at the distances of the relics. The high degree of polarization indicates that the magnetic field vectors are almost perfectly aligned along the relic structure, as expected for shock fronts that are observed edge-on. The polarization degrees correspond to Mach numbers of >2.2. Polarized emission is also detected in the radio relics in ZwCl 0008+52 and, for the first time, in Abell 1612. The smaller sizes and lower degrees of polarizations of the latter relics indicate a weaker shock and/or an inclination between the relic and the sky plane. Abell 1612 shows a complex X-ray surface brightness distribution, indicating a recent major merger and supporting the classification of the radio emission as a radio relic. In our cluster sample, no wavelength-dependent Faraday depolarization is detected between 4.85 GHz and 8.35 GHz, except for one component of the Toothbrush relic. Faraday depolarization between 1.38 GHz and 8.35 GHz varies with distance from the center of the host cluster 1RXS 06+42, which can be explained by a decrease in electron density and/or in strength of a turbulent (or tangled) magnetic field. Faraday rotation measures show large-scale gradients along the relics, which cannot be explained by variations in the Milky Way foreground. Conclusions: Single-dish telescopes are ideal tools to confirm relic candidates and search for new relic candidates. Measurement of the wavelength-dependent depolarization along the Toothbrush relic shows that the electron density of the intra-cluster medium (ICM) and strength of the tangled magnetic field decrease with distance from the center of the foreground cluster. Large-scale regular fields appear to be present in intergalactic space around galaxy clusters. Based on observations with the 100-m telescope at Effelsberg, operated by the Max-Planck-Institut für Radioastronomie (MPIfR) on behalf of the Max-Planck-Gesellschaft.The reduced Stokes parameter images (FITS files) are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/600/A18

Quantum and conversion efficiencies optimization of superstrate CIGS thin-films solar cells using In2Se3 buffer layer

NASA Astrophysics Data System (ADS)

Bouchama, Idris; Boudour, Samah; Bouarissa, Nadir; Rouabah, Zahir

2017-10-01

In this present contribution, AMPS-1D device simulator is employed to study the performances of superstrate SLG/TCO/p-Cu(In,Ga)Se2(CIGS)/n-ODC/n-In2Se3/Metal thin film solar cells. The impact of the TCO and Metal work functions on the cell performance has been investigated. The combination of optical transparency and electrical property for TCO front contact layer is found to yield high efficiency. The obtained results show that the TCO work function should be large enough to achieve high conversion efficiency for superstrate CIGS solar cell. Nevertheless, it is desirable for Metal back contact layer to have low work function to prevent the effect of band bending in the n-In2Se3/Metal interface. Several TCOs materials and metals have been tested respectively as a front and back contact layers for superstrate CIGS solar cells. An efficiency of 20.18%, with Voc ≈ 0.71 V, Jsc ≈ 35.36 mA/cm2 and FF ≈ 80.42%, has been achieved with ZnSn2O3-based as TCO front contact layer. In the case of SnO2:F front contact and indium back contact layers, an efficiency of 16.31%, with Voc ≈ 0.64 V, Jsc ≈ 31.4 mA/cm2 and FF ≈ 79.4%, has been obtained. The present results of simulation suggest an improvement of superstrate CIGS solar cells efficiency for feasible fabrication.

Another Shock for the Bullet Cluster, and the Source of Seed Electrons for Radio Relics

NASA Technical Reports Server (NTRS)

Shimwell, Timothy W,; Markevitch, Maxim; Brown, Shea; Feretti, Luigina; Gaensler, B. M.; Johnston-Hollitt, M.; Lage, Craig; Srinivasan, Raghav

2015-01-01

With Australia Telescope Compact Array observations, we detect a highly elongated Mpc-scale diffuse radio source on the eastern periphery of the Bullet cluster 1E 0657-55.8, which we argue has the positional, spectral and polarimetric characteristics of a radio relic. This powerful relic (2:30:11025 WHz(exp -1) consists of a bright northern bulb and a faint linear tail. The bulb emits 94% of the observed radio flux and has the highest surface brightness of any known relic. Exactly coincident with the linear tail we find a sharp X-ray surface brightness edge in the deep Chandra image of the cluster - a signature of a shock front in the hot intracluster medium (ICM), located on the opposite side of the cluster to the famous bow shock. This new example of an X-ray shock coincident with a relic further supports the hypothesis that shocks in the outer regions of clusters can form relics via diffusive shock (re- )acceleration. Intriguingly, our new relic suggests that seed electrons for reacceleration are coming from a local remnant of a radio galaxy, which we are lucky to catch before its complete disruption. If this scenario, in which a relic forms when a shock crosses a well-defined region of the ICM polluted with aged relativistic plasma - as opposed to the usual assumption that seeds are uniformly mixed in the ICM - is also the case for other relics, this may explain a number of peculiar properties of peripheral relics.

Twin radio relics in the nearby low-mass galaxy cluster Abell 168

NASA Astrophysics Data System (ADS)

Dwarakanath, K. S.; Parekh, V.; Kale, R.; George, L. T.

2018-06-01

We report the discovery of twin radio relics in the outskirts of the low-mass merging galaxy cluster Abell 168 (redshift=0.045). One of the relics is elongated with a linear extent ˜800 kpc and projected width of ˜80 kpc and is located ˜900 kpc towards the north of the cluster centre, oriented roughly perpendicular to the major axis of the X-ray emission. The second relic is ring-shaped with a size ˜220 kpc and is located near the inner edge of the elongated relic at a distance of ˜600 kpc from the cluster centre. These radio sources were imaged at 323 and 608 MHz with the Giant Meterwave Radio Telescope and at 1520 MHz with the Karl G. Jansky Very Large Array (VLA). The elongated relic was detected at all frequencies, with a radio power of 1.38 ± 0.14 × 1023 W Hz-1 at 1.4 GHz and a power law in the frequency range 70-1500 MHz (S ∝ να, α = -1.1 ± 0.04). This radio power is in good agreement with that expected from the known empirical relation between the radio powers of relics and host cluster masses. This is the lowest mass (M500 = 1.24 × 1014 M⊙) cluster in which relics due to merger shocks are detected. The ring-shaped relic has a steeper spectral index (α) of -1.74 ± 0.29 in the frequency range 100-600 MHz. We propose this relic to be an old plasma, revived due to adiabatic compression by the outgoing shock that produced the elongated relic.

Reduced Cu(InGa)Se 2 Thickness in Solar Cells Using a Superstrate Configuration

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shafarman, William N.

This project by the Institute of Energy Conversion (IEC) and the Department of Electrical and Computer Engineering at the University of Delaware sought to develop the technology and underlying science to enable reduced cost of Cu(InGa)Se 2 manufacturing by reducing the thickness of the Cu(InGa)Se 2 absorber layer by half compared to typical production. The approach to achieve this was to use the superstrate cell configuration in which light is incident on the cell through the glass. This structure facilitates optical enhancement approaches needed to achieve high efficiency with Cu(InGa)Se 2 thicknesses less than 1 µm. The primary objective wasmore » to demonstrate a Cu(InGa)Se 2 cell with absorber thickness 0.5 - 0.7 µm and 17% efficiency, along with a quantitative loss analysis to define a pathway to 20% efficiency. Additional objectives were the development of stable TCO and buffer layers or contact layers to withstand the Cu(InGa)Se 2 deposition temperature and of advanced optical enhancement methods. The underlying fundamental science needed to effectively transition these outcomes to large scale was addressed by extensive materials and device characterization and by development of comprehensive optical models. Two different superstrate configurations have been investigated. A frontwall cell is illuminated through the glass to the primary front junction of the device. This configuration has been used for previous efforts on superstrate Cu(InGa)Se 2 but performance has been limited by interdiffusion or reaction with CdS or other buffer layers. In this project, several approaches to overcome these limitations were explored using CdS, ZnO and ZnSe buffer layers. In each case, mechanisms that limit device performance were identified using detailed characterization of the materials and junctions. Due to the junction formation difficulties, efforts were concentrated on a new backwall configuration in which light is incident through the substrate into the back of the absorber layer. The primary junction is then formed after Cu(InGa)Se 2 deposition. This allows the potential benefits of superstrate cells for optical enhancement while maintaining processing advantages of the substrate configuration and avoiding the harmful effects of high temperature deposition on p-n junction formation. Backwall devices have outperformed substrate cells at absorber thicknesses of 0.1-0.5 µm through enhanced JSC due to easy incorporation of a Ag reflector and, with light incident on the absorber, the elimination of parasitic absorption in the CdS buffer. An efficiency of 9.7% has been achieved for a backwall Cu(InGa)Se 2 device with absorber thickness ~0.4 μm. A critical achievement that enabled implementation of the backwall cell was the development of a transparent back contact using MoO 3 or WO 3. Processes for controlled deposition of each material by reactive rf sputtering from metal targets were developed. These contacts have wide bandgaps making them well-suited for application as contacts for backwall devices as well as potential use in bifacial cells and as the top cell of tandem CuInSe 2-based devices. Optical enhancement will be critical for further improvements. Wet chemical texturing of ZnO films has been developed for a simple, low cost light-trapping scheme for backwall superstrate devices to enhance long wavelength quantum efficiency. An aqueous oxalic acid etch was developed and found to strongly texture sputtered ZnO with high haze ≈ 0.9 observed across the whole spectrum. And finally, advanced optical models have been developed to assist the characterization and optimization of Cu(InGa)Se 2 cells with thin absorbers« less

Superstring-inspired SO(10) GUT model with intermediate scale

NASA Astrophysics Data System (ADS)

Sasaki, Ken

1987-12-01

A new mechanism is proposed for the mixing of Weinberg-Salam Higgs fields in superstring-inspired SO(10) models with no SO(10) singlet fields. The higher-dimensional terms in the superpotential can generate both Higgs field mixing and a small mass for the physical neutrino. I would like to thank Professor C. Iso for hospitality extended to me at the Tokyo Institute of Technology.

Another shock for the Bullet cluster, and the source of seed electrons for radio relics

NASA Astrophysics Data System (ADS)

Shimwell, Timothy W.; Markevitch, Maxim; Brown, Shea; Feretti, Luigina; Gaensler, B. M.; Johnston-Hollitt, M.; Lage, Craig; Srinivasan, Raghav

2015-05-01

With Australia Telescope Compact Array observations, we detect a highly elongated Mpc-scale diffuse radio source on the eastern periphery of the Bullet cluster 1E 0657-55.8, which we argue has the positional, spectral and polarimetric characteristics of a radio relic. This powerful relic (2.3 ± 0.1 × 1025 W Hz-1) consists of a bright northern bulb and a faint linear tail. The bulb emits 94 per cent of the observed radio flux and has the highest surface brightness of any known relic. Exactly coincident with the linear tail, we find a sharp X-ray surface brightness edge in the deep Chandra image of the cluster - a signature of a shock front in the hot intracluster medium (ICM), located on the opposite side of the cluster to the famous bow shock. This new example of an X-ray shock coincident with a relic further supports the hypothesis that shocks in the outer regions of clusters can form relics via diffusive shock (re-)acceleration. Intriguingly, our new relic suggests that seed electrons for reacceleration are coming from a local remnant of a radio galaxy, which we are lucky to catch before its complete disruption. If this scenario, in which a relic forms when a shock crosses a well-defined region of the ICM polluted with aged relativistic plasma - as opposed to the usual assumption that seeds are uniformly mixed in the ICM - is also the case for other relics, this may explain a number of peculiar properties of peripheral relics.

Towards the final word on neutralino dark matter

NASA Astrophysics Data System (ADS)

Bramante, Joseph; Desai, Nishita; Fox, Patrick; Martin, Adam; Ostdiek, Bryan; Plehn, Tilman

2016-03-01

We present a complete phenomenological prospectus for thermal relic neutralinos. Including Sommerfeld enhancements to relic abundance and halo annihilation calculations, we obtain direct, indirect, and collider discovery prospects for all neutralinos with mass parameters M1 , M2 , |μ |<4 TeV , which freeze out to the observed dark matter abundance, with scalar superpartners decoupled. Much of the relic neutralino sector will be uncovered by the direct detection experiments Xenon1T and LZ, as well as indirect detection with Cerenkov Telescope Array. We emphasize that thermal relic Higgsinos will be found by next-generation direct detection experiments, so long as M1 ,2<4 TeV . Charged tracks at a 100 TeV hadron collider complement indirect searches for relic winos. Thermal relic bino-winos still evade all planned experiments, including disappearing charged-track searches. However, they can be discovered by compressed electroweakino searches at a 100 TeV collider, completing the full coverage of the relic neutralino surface.

Towards the final word on neutralino dark matter

DOE PAGES

Bramante, Joseph; Desai, Nishita; Fox, Patrick; ...

2016-03-25

We present a complete phenomenological prospectus for thermal relic neutralinos. Including Sommerfeld enhancements to relic abundance and halo annihilation calculations, we obtain direct, indirect, and collider discovery prospects for all neutralinos with mass parametersmore » $$M_1,M_2,|\\mu| < 4$$ TeV, that freeze out to the observed dark matter abundance, with scalar superpartners decoupled. Much of the relic neutralino sector will be uncovered by the direct detection experiments Xenon1T and LZ, as well as indirect detection with CTA. We emphasize that thermal relic higgsinos will be found by next-generation direct detection experiments, so long as $$M_{1,2} < 4$$ TeV. Charged tracks at a 100 TeV hadron collider complement indirect searches for relic winos. Thermal relic bino-winos still evade all planned experiments, including disappearing charged-track searches. Furthermore, they can be discovered by compressed electroweakino searches at a 100 TeV collider, completing the full coverage of the relic neutralino surface.« less

Far field focusing for a microwave patch antenna with composite substrate

NASA Astrophysics Data System (ADS)

Wan, Jian; Rybin, Oleg; Shulga, Sergey

2018-03-01

Modeling for a compact microwave antenna structure on base of a miniaturized rectangular patch antenna with composite substrate and magnetic superstrates is made in this study by using FDTD simulations. The resonant frequency of the antenna structure is supposed to be 15 GHz. The design of the antenna with composite substrate and without superstrate is made up by using the microwave miniaturization concept for rectangular patch antennas created by first author of this study. The optimal distance between the superstrate and antenna surface is found by using Fabry-Perot cavity theory as maximum values of power directivity and efficiency of the antenna is achieved. The comparative analysis with regard to some far and near field parameters of the above antenna structures and the antenna with dielectric substrate having same value of the relative permittivity is performed.

High‐Volume Processed, ITO‐Free Superstrates and Substrates for Roll‐to‐Roll Development of Organic Electronics

PubMed Central

Hösel, Markus; Angmo, Dechan; Søndergaard, Roar R.; dos Reis Benatto, Gisele A.; Carlé, Jon E.; Jørgensen, Mikkel

2014-01-01

The fabrication of substrates and superstrates prepared by scalable roll‐to‐roll methods is reviewed. The substrates and superstrates that act as the flexible carrier for the processing of functional organic electronic devices are an essential component, and proposals are made about how the general availability of various forms of these materials is needed to accelerate the development of the field of organic electronics. The initial development of the replacement of indium‐tin‐oxide (ITO) for the flexible carrier materials is described and a description of how roll‐to‐roll processing development led to simplification from an initially complex make‐up to higher performing materials through a more simple process is also presented. This process intensification through process simplification is viewed as a central strategy for upscaling, increasing throughput, performance, and cost reduction. PMID:27980893

Primitive environment control for preservation of pit relics in archeology museums of China.

PubMed

Gu, Zhaolin; Luo, Xilian; Meng, Xiangzhao; Wang, Zanshe; Ma, Tao; Yu, Chuck; Rong, Bo; Li, Ku; Li, Wenwu; Tan, Ying

2013-02-05

Immovable historical relics in some archeology museums of China suffer deterioration due to their improper preservation environment. The existing environmental control systems used in archeology museums are often designed for the amenities of visitors, and these manipulated environments are often inappropriate for the conservation of abiotic relics. This paper points out that the large open space of the existing archeology museum could be a cause of deterioration of the relics from the point of view of indoor air convective flow. The paper illustrates the need to introduce a local pit environmental control, which could reintegrate a pit primitive environment for the preservation of the historical relics by using an air curtain system, orientated to isolate the unearthed relics, semiexposed in pits to the large gallery open space of the exhibition hall.

String theory, gauge theory and quantum gravity. Proceedings. Trieste Spring School and Workshop on String Theory, Gauge Theory and Quantum Gravity, Trieste (Italy), 11 - 22 Apr 1994.

NASA Astrophysics Data System (ADS)

1995-04-01

The following topics were dealt with: string theory, gauge theory, quantum gravity, quantum geometry, black hole physics and information loss, second quantisation of the Wilson loop, 2D Yang-Mills theory, topological field theories, equivariant cohomology, superstring theory and fermion masses, supergravity, topological gravity, waves in string cosmology, superstring theories, 4D space-time.

Module/array interface study

NASA Technical Reports Server (NTRS)

1978-01-01

Several aspects of module design are evaluated, including glass superstrate and metal substrate module configurations, the potential for hail damage, light absorption in glass superstrates, the economics of glass selection, and electrical design. Also, three alternate glass superstrate module configurations are evaluated by means of finite element computer analyses. Two panel sizes, 1.2 by 2.4 m (4 by 8 ft) and 2.4 by 4.8 m are used to support three module sizes, 0.6 by 1.2 m, 1.2 by 1.2 m, and 1.2 by 2.4 m, for design loadings of + or - 1.7 kPa, + or - 2.4 kPa, and + or - 3.6 kPa. Designs and cost estimates are presented for twenty panel types and nine array configurations at each of the three design loadings. Structural cost sensitivities of combined array configurations and panel cases are presented.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pern, F.J.; Glick, S.H.; Czanderna, A.W.

The stabilization effects of various superstrate materials against UV-induced EVA discoloration and the effect of photocurrent enhancement by white light-reflecting substrates are summarized. Based on the results, some alternative PV module encapsulation schemes are proposed for improved module performance, where the current or modified formulations of EVA encapsulants still can be used so that the typical processing tools and conditions need not to be changed significantly. The schemes are designed in an attempt to eliminate or minimize the EVA yellow-browning and to increase the module power output. Four key experimental results from the studies of EVA discoloration and encapsulation aremore » to employ: (1) UV-absorbing (filtering) glasses as superstrates to protect EVA from UV-induced discoloration, (2) gas-permeable polymer films as superstrates and/or substrates to prevent EVA yellowing by permitting photobleaching reactions, (3) modified EVA formulations, and (4) internal reflection of the light by white substrates. {copyright} {ital 1996 American Institute of Physics.}« less

XMM-Newton Observations of the Southeastern Radio Relic in Abell 3667

NASA Astrophysics Data System (ADS)

Storm, Emma; Vink, Jacco; Zandanel, Fabio; Akamatsu, Hiroki

2018-06-01

Radio relics, elongated, non-thermal, structures located at the edges of galaxy clusters, are the result of synchrotron radiation from cosmic-ray electrons accelerated by merger-driven shocks at the cluster outskirts. However, X-ray observations of such shocks in some clusters suggest that they are too weak to efficiently accelerate electrons via diffusive shock acceleration to energies required to produce the observed radio power. We examine this issue in the merging galaxy cluster Abell 3667 (A3667), which hosts a pair of radio relics. While the Northwest relic in A3667 has been well studied in the radio and X-ray by multiple instruments, the Southeast relic region has only been observed so far by Suzaku, which detected a temperature jump across the relic, suggesting the presence of a weak shock. We present observations of the Southeastern region of A3667 with XMM-Newton centered on the radio relic. We confirm the existence of an X-ray shock with Mach number of about 1.8 from a clear detection of temperature jump and a tentative detection of a density jump, consistent with previous measurements by Suzaku. We discuss the implications of this measurement for diffusive shock acceleration as the main mechanism for explaining the origin of radio relics. We then speculate on the plausibility of alternative scenarios, including re-acceleration and variations in the Mach number along shock fronts.

Thermoelectric generator and method for the fabrication thereof

DOEpatents

Benson, David K.; Tracy, C. Edwin

1987-01-01

A thermoelectric generator using semiconductor elements for responding to a temperature gradient to produce electrical energy with all of the semiconductor elements being of the same type is disclosed. A continuous process for forming substrates on which the semiconductor elements and superstrates are deposited and a process for forming the semiconductor elements on the substrates are also disclosed. The substrates with the semiconductor elements thereon are combined with superstrates to form modules for use thermoelectric generators.

Thermoelectric generator and method for the fabrication thereof

DOEpatents

Benson, D.K.; Tracy, C.E.

1984-08-01

A thermoelectric generator using semiconductor elements for responding to a temperature gradient to produce electrical energy with all of the semiconductor elements being of the same type is disclosed. A continuous process for forming substrates on which the semiconductor elements and superstrates are deposited and a process for forming the semiconductor elements on the substrates are also disclosed. The substrates with the semiconductor elements thereon are combined with superstrates to form modules for use as thermoelectric generators.

Amorphous oxides as electron transport layers in Cu(In,Ga)Se 2 superstrate devices: Amorphous oxides in Cu(In,Ga)Se 2 superstrate devices

DOE Office of Scientific and Technical Information (OSTI.GOV)

Heinemann, M. D.; van Hest, M. F. A. M.; Contreras, M.

Cu(In,Ga)Se2 (CIGS) solar cells in superstrate configuration promise improved light management and higher stability compared to substrate devices, but they have yet to deliver comparable power conversion efficiencies (PCEs). Chemical reactions between the CIGS layer and the front contact were shown in the past to deteriorate the p-n junction in superstrate devices, which led to lower efficiencies compared to the substrate-type devices. This work aims to solve this problem by identifying a buffer layer between the CIGS layer and the front contact, acting as the electron transport layer, with an optimized electron affinity, doping density and chemical stability. Using combinatorialmore » material exploration we identified amorphous gallium oxide (a-GaOx) as a potentially suitable buffer layer material. The best results were obtained for a-GaOx with an electron affinity that was found to be comparable to that of CIGS. Based on the results of device simulations, it is assumed that detrimental interfacial acceptor states are present at the interface between CIGS and a-GaOx. However, these initial experiments indicate the potential of a-GaOx in this application, and how to reach performance parity with substrate devices, by further increase of its n-type doping density.« less

The Big Bang, Superstring Theory and the origin of life on the Earth.

PubMed

Trevors, J T

2006-03-01

This article examines the origin of life on Earth and its connection to the Superstring Theory, that attempts to explain all phenomena in the universe (Theory of Everything) and unify the four known forces and relativity and quantum theory. The four forces of gravity, electro-magnetism, strong and weak nuclear were all present and necessary for the origin of life on the Earth. It was the separation of the unified force into four singular forces that allowed the origin of life.

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.

Localization of effective actions in open superstring field theory

NASA Astrophysics Data System (ADS)

Maccaferri, Carlo; Merlano, Alberto

2018-03-01

We consider the construction of the algebraic part of D-branes tree-level effective action from Berkovits open superstring field theory. Applying this construction to the quartic potential of massless fields carrying a specific worldsheet charge, we show that the full contribution to the potential localizes at the boundary of moduli space, reducing to elementary two-point functions. As examples of this general mechanism, we show how the Yang-Mills quartic potential and the instanton effective action of a Dp/D( p - 4) system are reproduced.

a Review of Digital Watermarking and Copyright Control Technology for Cultural Relics

NASA Astrophysics Data System (ADS)

Liu, H.; Hou, M.; Hu, Y.

2018-04-01

With the rapid growth of the application and sharing of the 3-D model data in the protection of cultural relics, the problem of Shared security and copyright control of the three-dimensional model of cultural relics is becoming increasingly prominent. Followed by a digital watermarking copyright control has become the frontier technology of 3-D model security protection of cultural relics and effective means, related technology research and application in recent years also got further development. 3-D model based on cultural relics digital watermarking and copyright control technology, introduces the research background and demand, its unique characteristics were described, and its development and application of the algorithm are discussed, and the prospects of the future development trend and some problems and the solution.

Mapping the ecological dimensions and potential distributions of endangered relic shrubs in western Ordos biodiversity center

PubMed Central

Zhu, Geng-Ping; Li, Hui-Qi; Zhao, Li; Man, Liang; Liu, Qiang

2016-01-01

Potential distributions of endemic relic shrubs in western Ordos were poorly mapped, which hindered our implementation of proper conservation. Here we investigated the applicability of ecological niche modeling for endangered relic shrubs to detect areas of priority for biodiversity conservation and analyze differences in ecological niche spaces used by relic shrubs. We applied ordination and niche modeling techniques to assess main environmental drivers of five endemic relic shrubs in western Ordos, namely, Ammopiptanthus mongolicus, Amygdalus mongolica, Helianthemum songaricum, Potaninia mongolica, and Tetraena mongolica. We calculated niche overlap metrics in gridded environmental spaces and compared geographical projections of ecological niches to determine similarities and differences of niches occupied by relic shrubs. All studied taxa presented different responses to environmental factors, which resulted in a unique combination of niche conditions. Precipitation availability and soil quality characteristics play important roles in the distributions of most shrubs. Each relic shrub is constrained by a unique set of environmental conditions, the distribution of one species cannot be implied by the distribution of another, highlighting the inadequacy of one-fits-all type of conservation measure. Our stacked habitat suitability maps revealed regions around Yellow River, which are highly suitable for most species, thereby providing high conservation value. PMID:27199260

Mapping the ecological dimensions and potential distributions of endangered relic shrubs in western Ordos biodiversity center.

PubMed

Zhu, Geng-Ping; Li, Hui-Qi; Zhao, Li; Man, Liang; Liu, Qiang

2016-05-20

Potential distributions of endemic relic shrubs in western Ordos were poorly mapped, which hindered our implementation of proper conservation. Here we investigated the applicability of ecological niche modeling for endangered relic shrubs to detect areas of priority for biodiversity conservation and analyze differences in ecological niche spaces used by relic shrubs. We applied ordination and niche modeling techniques to assess main environmental drivers of five endemic relic shrubs in western Ordos, namely, Ammopiptanthus mongolicus, Amygdalus mongolica, Helianthemum songaricum, Potaninia mongolica, and Tetraena mongolica. We calculated niche overlap metrics in gridded environmental spaces and compared geographical projections of ecological niches to determine similarities and differences of niches occupied by relic shrubs. All studied taxa presented different responses to environmental factors, which resulted in a unique combination of niche conditions. Precipitation availability and soil quality characteristics play important roles in the distributions of most shrubs. Each relic shrub is constrained by a unique set of environmental conditions, the distribution of one species cannot be implied by the distribution of another, highlighting the inadequacy of one-fits-all type of conservation measure. Our stacked habitat suitability maps revealed regions around Yellow River, which are highly suitable for most species, thereby providing high conservation value.

Cosmic superstrings: Observable remnants of brane inflation

NASA Astrophysics Data System (ADS)

Wyman, Mark Charles

Brane inflation provides a natural dynamical model for the physics which underlie the inflationary paradigm. Besides their inflationary predictions, brane models imply another observable consequence: cosmic strings. In this dissertation I outline the background of how cosmic strings arise in brane inflationary models and how the properties of the strings and the models are mutually tied (Chapter 2). I then use cosmological observations to put limits on the properties of any actually-existing cosmic string network (Chapter 3). Next, I study the question of how cosmic superstrings, as the cosmic strings arising from string theory are known, could be distinct from classical gauge- theory cosmic strings. In particular, I propose an analytical model for the cosmological evolution of a network of binding cosmic strings (Chapter 4); I also describe the distinctive gravitational lensing phenomena that are caused by binding strings (Chapter 5). Finally, I lay out the background for the numerical study of a gauge theory model for the dynamics of cosmic superstring binding (Chapter 6).

The AdS{sub 5}xS{sup 5} superstring worldsheet S matrix and crossing symmetry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Janik, Romuald A.

2006-04-15

An S matrix satisfying the Yang-Baxter equation with symmetries relevant to the AdS{sub 5}xS{sup 5} superstring recently has been determined up to an unknown scalar factor. Such scalar factors are typically fixed using crossing relations; however, due to the lack of conventional relativistic invariance, in this case its determination remained an open problem. In this paper we propose an algebraic way to implement crossing relations for the AdS{sub 5}xS{sup 5} superstring worldsheet S matrix. We base our construction on a Hopf-algebraic formulation of crossing in terms of the antipode and introduce generalized rapidities living on the universal cover of themore » parameter space which is constructed through an auxillary, coupling-constant dependent, elliptic curve. We determine the crossing transformation and write functional equations for the scalar factor of the S matrix in the generalized rapidity plane.« less

A Module Experimental Process System Development Unit (MEPSDU)

NASA Technical Reports Server (NTRS)

1981-01-01

Design work for a photovoltaic module, fabricated using single crystal silicon dendritic web sheet material, resulted in the identification of surface treatment to the module glass superstrate which improved module efficiencies. A final solar module environmental test, a simulated hailstone impact test, was conducted on full size module superstrates to verify that the module's tempered glass superstrate can withstand specified hailstone impacts near the corners and edges of the module. Process sequence design work on the metallization process selective, liquid dopant investigation, dry processing, and antireflective/photoresist application technique tasks, and optimum thickness for Ti/Pd are discussed. A noncontact cleaning method for raw web cleaning was identified and antireflective and photoresist coatings for the dendritic webs were selected. The design of a cell string conveyor, an interconnect feed system, rolling ultrasonic spot bonding heat, and the identification of the optimal commercially available programmable control system are also discussed. An economic analysis to assess cost goals of the process sequence is also given.

The impact of the SZ effect on cm-wavelength (1-30 GHz) observations of galaxy cluster radio relics

NASA Astrophysics Data System (ADS)

Basu, Kaustuv; Vazza, Franco; Erler, Jens; Sommer, Martin

2016-07-01

Radio relics in galaxy clusters are believed to be associated with powerful shock fronts that originate during cluster mergers, and are a testbed for the acceleration of relativistic particles in the intracluster medium. Recently, radio relic observations have pushed into the cm-wavelength domain (1-30 GHz) where a break from the standard synchrotron power law spectrum has been found, most noticeably in the famous "Sausage" relic. Such spectral steepening is seen as an evidence for non-standard relic models, such as ones requiring seed electron population with a break in their energy spectrum. In this paper, however, we point to an important effect that has been ignored or considered insignificant while interpreting these new high-frequency radio data, namely the contamination due to the Sunyaev-Zel'dovich (SZ) effect that changes the observed synchrotron flux. Even though the radio relics reside in the cluster outskirts, the shock-driven pressure boost increases the SZ signal locally by roughly an order of magnitude. The resulting flux contamination for some well-known relics are non-negligible already at 10 GHz, and at 30 GHz the observed synchrotron fluxes can be diminished by a factor of several from their true values. At higher redshift the contamination gets stronger due to the redshift independence of the SZ effect. Interferometric observations are not immune to this contamination, since the change in the SZ signal occurs roughly at the same length scale as the synchrotron emission, although there the flux loss is less severe than single-dish observations. Besides presenting this warning to observers, we suggest that the negative contribution from the SZ effect can be regarded as one of the best evidence for the physical association between radio relics and shock waves. We present a simple analytical approximation for the synchrotron-to-SZ flux ratio, based on a theoretical radio relic model that connects the nonthermal emission to the thermal gas properties, and show that by measuring this ratio one can potentially estimate the relic magnetic fields or the particle acceleration efficiency.

Grand unification scale primordial black holes: consequences and constraints.

PubMed

Anantua, Richard; Easther, Richard; Giblin, John T

2009-09-11

A population of very light primordial black holes which evaporate before nucleosynthesis begins is unconstrained unless the decaying black holes leave stable relics. We show that gravitons Hawking radiated from these black holes would source a substantial stochastic background of high frequency gravititational waves (10(12) Hz or more) in the present Universe. These black holes may lead to a transient period of matter-dominated expansion. In this case the primordial Universe could be temporarily dominated by large clusters of "Hawking stars" and the resulting gravitational wave spectrum is independent of the initial number density of primordial black holes.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gillioz, M.; von Manteuffel, A.; Schwaller, P.

We study skyrmions in the littlest Higgs model and discuss their possible role as dark matter candidates. Stable massive skyrmions can exist in the littlest Higgs model also in absence of an exact parity symmetry, since they carry a conserved topological charge due to the non-trivial third homotopy group of the SU(5)/SO(5) coset. We find a spherically symmetric skyrmion solution in this coset. The effects of gauge fields on the skyrmion solutions are analyzed and found to lead to an upper bound on the skyrmion mass. The relic abundance is in agreement with the observed dark matter density for reasonablemore » parameter choices.« less

TURBULENT COSMIC-RAY REACCELERATION AT RADIO RELICS AND HALOS IN CLUSTERS OF GALAXIES

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fujita, Yutaka; Takizawa, Motokazu; Yamazaki, Ryo

Radio relics are synchrotron emission found on the periphery of galaxy clusters. From the position and the morphology, it is often believed that the relics are generated by cosmic-ray (CR) electrons accelerated at shocks through a diffusive shock acceleration (DSA) mechanism. However, some radio relics have harder spectra than the prediction of the standard DSA model. One example is observed in the cluster 1RXS J0603.3+4214, which is often called the “Toothbrush Cluster.” Interestingly, the position of the relic is shifted from that of a possible shock. In this study, we show that these discrepancies in the spectrum and the positionmore » can be solved if turbulent (re)acceleration is very effective behind the shock. This means that for some relics turbulent reacceleration may be the main mechanism to produce high-energy electrons, contrary to the common belief that it is the DSA. Moreover, we show that for efficient reacceleration, the effective mean free path of the electrons has to be much smaller than their Coulomb mean free path. We also study the merging cluster 1E 0657−56, or the “Bullet Cluster,” in which a radio relic has not been found at the position of the prominent shock ahead of the bullet. We indicate that a possible relic at the shock is obscured by the observed large radio halo that is generated by strong turbulence behind the shock. We propose a simple explanation of the morphological differences of radio emission among the Toothbrush, the Bullet, and the Sausage (CIZA J2242.8+5301) Clusters.« less

On the BV formalism of open superstring field theory in the large Hilbert space

NASA Astrophysics Data System (ADS)

Matsunaga, Hiroaki; Nomura, Mitsuru

2018-05-01

We construct several BV master actions for open superstring field theory in the large Hilbert space. First, we show that a naive use of the conventional BV approach breaks down at the third order of the antifield number expansion, although it enables us to define a simple "string antibracket" taking the Darboux form as spacetime antibrackets. This fact implies that in the large Hilbert space, "string fields-antifields" should be reassembled to obtain master actions in a simple manner. We determine the assembly of the string anti-fields on the basis of Berkovits' constrained BV approach, and give solutions to the master equation defined by Dirac antibrackets on the constrained string field-antifield space. It is expected that partial gauge-fixing enables us to relate superstring field theories based on the large and small Hilbert spaces directly: reassembling string fields-antifields is rather natural from this point of view. Finally, inspired by these results, we revisit the conventional BV approach and construct a BV master action based on the minimal set of string fields-antifields.

REVIEWS OF TOPICAL PROBLEMS: Relic gravitational waves and cosmology

NASA Astrophysics Data System (ADS)

Grishchuk, Leonid P.

2005-12-01

The paper begins with a brief recollection of interactions of the author with Ya B Zeldovich in the context of the study of relic gravitational waves. The principles and early results on the quantum-mechanical generation of cosmological perturbations are then summarized. The expected amplitudes of relic gravitational waves differ in various frequency windows, and therefore the techniques and prospects of their detection are distinct. One section of the paper describes the present state of efforts in direct detection of relic gravitational waves. Another section is devoted to indirect detection via the anisotropy and polarization measurements of the cosmic microwave background (CMB) radiation. It is emphasized throughout the paper that the inference about the existence and expected amount of relic gravitational waves is based on a solid theoretical foundation and the best available cosmological observations. It is also explained in great detail what went wrong with the so-called 'inflationary gravitational waves', whose amount is predicted by inflationary theorists to be negligibly small, thus depriving them of any observational significance.

The Birth of String Theory

NASA Astrophysics Data System (ADS)

Cappelli, Andrea; Castellani, Elena; Colomo, Filippo; Di Vecchia, Paolo

2012-04-01

Part I. Overview: 1. Introduction and synopsis; 2. Rise and fall of the hadronic string G. Veneziano; 3. Gravity, unification, and the superstring J. H. Schwarz; 4. Early string theory as a challenging case study for philosophers E. Castellani; Part II. The Prehistory: The Analytic S-Matrix: 5. Introduction to Part II; 6. Particle theory in the sixties: from current algebra to the Veneziano amplitude M. Ademollo; 7. The path to the Veneziano model H. R. Rubinstein; 8. Two-component duality and strings P. G. O. Freund; 9. Note on the prehistory of string theory M. Gell-Mann; Part III. The Dual Resonance Model: 10. Introduction to Part III; 11. From the S-matrix to string theory P. Di Vecchia; 12. Reminiscence on the birth of string theory J. A. Shapiro; 13. Personal recollections D. Amati; 14. Early string theory at Fermilab and Rutgers L. Clavelli; 15. Dual amplitudes in higher dimensions: a personal view C. Lovelace; 16. Personal recollections on dual models R. Musto; 17. Remembering the 'supergroup' collaboration F. Nicodemi; 18. The '3-Reggeon vertex' S. Sciuto; Part IV. The String: 19. Introduction to Part IV; 20. From dual models to relativistic strings P. Goddard; 21. The first string theory: personal recollections L. Susskind; 22. The string picture of the Veneziano model H. B. Nielsen; 23. From the S-matrix to string theory Y. Nambu; 24. The analogue model for string amplitudes D. B. Fairlie; 25. Factorization in dual models and functional integration in string theory S. Mandelstam; 26. The hadronic origins of string theory R. C. Brower; Part V. Beyond the Bosonic String: 27. Introduction to Part V; 28. From dual fermion to superstring D. I. Olive; 29. Dual models with fermions: memoirs of an early string theorist P. Ramond; 30. Personal recollections A. Neveu; 31. Aspects of fermionic dual models E. Corrigan; 32. The dual quark models K. Bardakci and M. B. Halpern; 33. Remembering the dawn of relativistic strings J.-L. Gervais; 34. Early string theory in Cambridge: personal recollections C. Montonen; Part VI. The Superstring: 35. Introduction to Part VI; 36. Supersymmetry in string theory F. Gliozzi; 37. Gravity from strings: personal reminiscences of early developments T. Yoneya; 38. From the Nambu-Goto to the σ-model action L. Brink; 39. Locally supersymmetric action for superstring P. Di Vecchia; 40. Personal recollections E. Cremmer; 41. The scientific contributions of Joël Scherk J. H. Schwarz; Part VII. Preparing the String Renaissance: 42. Introduction to Part VII; 43. From strings to superstrings: a personal perspective M. B. Green; 44. Quarks, strings and beyond A. M. Polyakov; 45. The rise of the superstring theory A. Cappelli and F. Colomo; Appendices; Index.

Linking axionlike dark matter to neutrino masses

NASA Astrophysics Data System (ADS)

Carvajal, C. D. R.; Sánchez-Vega, B. L.; Zapata, O.

2017-12-01

We present a framework linking axionlike particles (ALPs) to neutrino masses through the minimal inverse seesaw (ISS) mechanism in order to explain the dark matter (DM) puzzle. Specifically, we explore three minimal ISS cases where mass scales are generated through gravity-induced operators involving a scalar field hosting ALPs. In all of these cases, we find gravity-stable models that provide the observed DM relic density and, simultaneously, are consistent with the phenomenology of neutrinos and ALPs. Remarkably, in one of the ISS cases, the DM can be made of ALPs and sterile neutrinos. Furthermore, other considered ISS cases have ALPs with parameters that are within the reach of proposed ALP experiments.

Axion dark matter in a 3 -3 -1 model

NASA Astrophysics Data System (ADS)

Montero, J. C.; Romero Castellanos, Ana R.; Sánchez-Vega, B. L.

2018-03-01

Slightly extending a right-handed neutrino version of the 3 -3 -1 model, we show that it is not only possible to solve the strong C P problem but also to give the total dark matter abundance reported by the Planck collaboration. Specifically, we consider the possibility of introducing a 3 -3 -1 scalar singlet to implement a gravity stable Peccei-Quinn mechanism in this model. Remarkably, for allowed regions of the parameter space, the arising axions with masses ma≈meV can both make up the total dark matter relic density through nonthermal production mechanisms and be very close to the region to be explored by the IAXO helioscope.

Radio observations of the double-relic galaxy cluster Abell 1240

NASA Astrophysics Data System (ADS)

Hoang, D. N.; Shimwell, T. W.; van Weeren, R. J.; Intema, H. T.; Röttgering, H. J. A.; Andrade-Santos, F.; Akamatsu, H.; Bonafede, A.; Brunetti, G.; Dawson, W. A.; Golovich, N.; Best, P. N.; Botteon, A.; Brüggen, M.; Cassano, R.; de Gasperin, F.; Hoeft, M.; Stroe, A.; White, G. J.

2018-05-01

We present LOFAR 120 - 168 MHz images of the merging galaxy cluster Abell 1240 that hosts double radio relics. In combination with the GMRT 595 - 629 MHz and VLA 2 - 4 GHz data, we characterised the spectral and polarimetric properties of the radio emission. The spectral indices for the relics steepen from their outer edges towards the cluster centre and the electric field vectors are approximately perpendicular to the major axes of the relics. The results are consistent with the picture that these relics trace large-scale shocks propagating outwards during the merger. Assuming diffusive shock acceleration (DSA), we obtain shock Mach numbers of M=2.4 and 2.3 for the northern and southern shocks, respectively. For M≲ 3 shocks, a pre-existing population of mildly relativistic electrons is required to explain the brightness of the relics due to the high (>10 per cent) particle acceleration efficiency required. However, for M≳ 4 shocks the required efficiency is ≳ 1% and ≳ 0.5%, respectively, which is low enough for shock acceleration directly from the thermal pool. We used the fractional polarization to constrain the viewing angle to ≥53 ± 3° and ≥39 ± 5° for the northern and southern shocks, respectively. We found no evidence for diffuse emission in the cluster central region. If the halo spans the entire region between the relics (˜1.8 Mpc) our upper limit on the power is P1.4GHz = (1.4 ± 0.6) × 1023 W Hz-1 which is approximately equal to the anticipated flux from a cluster of this mass. However, if the halo is smaller than this, our constraints on the power imply that the halo is underluminous.

DIFFUSIVE SHOCK ACCELERATION SIMULATIONS OF RADIO RELICS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kang, Hyesung; Ryu, Dongsu; Jones, T. W., E-mail: kang@uju.es.pusan.ac.kr, E-mail: ryu@canopus.cnu.ac.kr, E-mail: twj@msi.umn.edu

2012-09-01

Recent radio observations have identified a class of structures, so-called radio relics, in clusters of galaxies. The radio emission from these sources is interpreted as synchrotron radiation from GeV electrons gyrating in {mu}G-level magnetic fields. Radio relics, located mostly in the outskirts of clusters, seem to associate with shock waves, especially those developed during mergers. In fact, they seem to be good structures to identify and probe such shocks in intracluster media (ICMs), provided we understand the electron acceleration and re-acceleration at those shocks. In this paper, we describe time-dependent simulations for diffusive shock acceleration at weak shocks that aremore » expected to be found in ICMs. Freshly injected as well as pre-existing populations of cosmic-ray (CR) electrons are considered, and energy losses via synchrotron and inverse Compton are included. We then compare the synchrotron flux and spectral distributions estimated from the simulations with those in two well-observed radio relics in CIZA J2242.8+5301 and ZwCl0008.8+5215. Considering that CR electron injection is expected to be rather inefficient at weak shocks with Mach number M {approx}< a few, the existence of radio relics could indicate the pre-existing population of low-energy CR electrons in ICMs. The implication of our results on the merger shock scenario of radio relics is discussed.« less

Classical and quantum production of cornucopions at energies below 1018 GeV

NASA Astrophysics Data System (ADS)

Banks, T.; O'loughlin, M.

1993-01-01

We argue that the paradoxes associated with infinitely degenerate states, which plague relic particle scenarios for the end point of black hole evaporation, may be absent when the relics are horned particles. Most of our arguments are based on simple observations about the classical geometry of extremal dilaton black holes, but at a crucial point we are forced to speculate about classical solutions to string theory in which the infinite coupling singularity of the extremal dilaton solution is shielded by a condensate of massless modes propagating in its infinite horn. We use the nonsingular c=1 solution of (1+1)-dimensional string theory as a crude model for the properties of the condensate. We also present a brief discussion of more general relic scenarios based on large relics of low mass.

Multiloop amplitudes of light-cone gauge superstring field theory: odd spin structure contributions

NASA Astrophysics Data System (ADS)

Ishibashi, Nobuyuki; Murakami, Koichi

2018-03-01

We study the odd spin structure contributions to the multiloop amplitudes of light-cone gauge superstring field theory. We show that they coincide with the amplitudes in the conformal gauge with two of the vertex operators chosen to be in the pictures different from the standard choice, namely (-1, -1) picture in the type II case and -1 picture in the heterotic case. We also show that the contact term divergences can be regularized in the same way as in the amplitudes for the even structures and we get the amplitudes which coincide with those obtained from the first-quantized approach.

Scaling properties of cosmic (super)string networks

NASA Astrophysics Data System (ADS)

Martins, C. J. A. P.

2014-10-01

I use a combination of state-of-the-art numerical simulations and analytic modelling to discuss the scaling properties of cosmic defect networks, including superstrings. Particular attention is given to the role of extra degrees of freedom in the evolution of these networks. Compared to the 'plain vanilla' case of Goto-Nambu strings, three such extensions play important but distinct roles in the network dynamics: the presence of charges/currents on the string worldsheet, the existence of junctions, and the possibility of a hierarchy of string tensions. I also comment on insights gained from studying simpler defect networks, including Goto-Nambu strings themselves, domain walls and semilocal strings.

Apollo(R) Thin Film Process Development: Final Technical Report, April 1998 - April 2002

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cunningham, D.W.

2002-10-01

BP Solar first started investigative work on CdTe photovoltaics in 1986. The module product name chosen for the CdTe devices is Apollo. The deposition method chosen was electrochemical deposition due to its simplicity and good control of stoichiometric composition. The window layer used is CdS, produced from a chemical-bath deposition. Initial work focused on increasing photovoltaic cell size from a few mm2 to 900 cm2. At BP Solar's Fairfield plant, work is focused on increasing semiconductor deposition to 1 m2. The primary objective of this subcontract is to establish the conditions required for the efficient plating of CdS/CdTe on large-area,more » transparent conducting tin-oxide-coated glass superstrate. The initial phase concentrates on superstrate sizes up to 0.55 m2. Later phases will include work on 0.94 m2 superstrates. The tasks in this subcontract have been split into four main categories: (1) CdS and CdTe film studies; (2) Enhanced laser processing; (3) Outdoor testing program for the Apollo module; and (4) Production waste abatement and closed loop study.« less

Relic galaxies: where are they?

NASA Astrophysics Data System (ADS)

Peralta de Arriba, L.; Quilis, V.; Trujillo, I.; Cebrián, M.; Balcells, M.

2017-03-01

The finding that massive galaxies grow with cosmic time fired the starting gun for the search of objects which could have survived up to the present day without suffering substantial changes (neither in their structures, neither in their stellar populations). Nevertheless, and despite the community efforts, up to now only one firm candidate to be considered one of these relics is known: NGC 1277. Curiously, this galaxy is located at the centre of one of the most rich near galaxy clusters: Perseus. Is its location a matter of chance? Should relic hunters focus their search on galaxy clusters? In order to reply this question, we have performed a simultaneous and analogous analysis using simulations (Millennium I-WMAP7) and observations (New York University Value-Added Galaxy Catalogue). Our results in both frameworks agree: it is more probable to find relics in high density environments.

Multi-wavelength Observations of the Dissociative Merger in the Galaxy Cluster CIZA J0107.7+5408

NASA Astrophysics Data System (ADS)

Randall, S. W.; Clarke, T. E.; van Weeren, R. J.; Intema, H. T.; Dawson, W. A.; Mroczkowski, T.; Blanton, E. L.; Bulbul, E.; Giacintucci, S.

2016-06-01

We present results based on X-ray, optical, and radio observations of the massive galaxy cluster CIZA J0107.7+5408. We find that this system is a post-core-passage, dissociative, binary merger, with the optical galaxy density peaks of each subcluster leading their associated X-ray emission peaks. This separation occurs because the diffuse gas experiences ram pressure forces, while the effectively collisionless galaxies (and presumably their associated dark matter (DM) halos) do not. This system contains double-peaked diffuse radio emission, possibly a double radio relic with the relics lying along the merger axis and also leading the X-ray cores. We find evidence for a temperature peak associated with the SW relic, likely created by the same merger shock that is powering the relic radio emission in this region. Thus, this system is a relatively rare, clean example of a dissociative binary merger, which can in principle be used to place constraints on the self-interaction cross-section of DM. Low-frequency radio observations reveal ultra-steep spectrum diffuse radio emission that is not correlated with the X-ray, optical, or high-frequency radio emission. We suggest that these sources are radio phoenixes, which are preexisting non-thermal particle populations that have been re-energized through adiabatic compression by the same merger shocks that power the radio relics. Finally, we place upper limits on inverse Compton emission from the SW radio relic.

MULTI-WAVELENGTH OBSERVATIONS OF THE DISSOCIATIVE MERGER IN THE GALAXY CLUSTER CIZA J0107.7+5408

DOE Office of Scientific and Technical Information (OSTI.GOV)

Randall, S. W.; Weeren, R. J. van; Clarke, T. E.

We present results based on X-ray, optical, and radio observations of the massive galaxy cluster CIZA J0107.7+5408. We find that this system is a post-core-passage, dissociative, binary merger, with the optical galaxy density peaks of each subcluster leading their associated X-ray emission peaks. This separation occurs because the diffuse gas experiences ram pressure forces, while the effectively collisionless galaxies (and presumably their associated dark matter (DM) halos) do not. This system contains double-peaked diffuse radio emission, possibly a double radio relic with the relics lying along the merger axis and also leading the X-ray cores. We find evidence for amore » temperature peak associated with the SW relic, likely created by the same merger shock that is powering the relic radio emission in this region. Thus, this system is a relatively rare, clean example of a dissociative binary merger, which can in principle be used to place constraints on the self-interaction cross-section of DM. Low-frequency radio observations reveal ultra-steep spectrum diffuse radio emission that is not correlated with the X-ray, optical, or high-frequency radio emission. We suggest that these sources are radio phoenixes, which are preexisting non-thermal particle populations that have been re-energized through adiabatic compression by the same merger shocks that power the radio relics. Finally, we place upper limits on inverse Compton emission from the SW radio relic.« less

Multi-wavelength Observations of the Dissociative Merger in the Galaxy Cluster CIZA J0107.7+5408

DOE Office of Scientific and Technical Information (OSTI.GOV)

Randall, S. W.; Clarke, T. E.; Weeren, R. J. van

We present results based on X-ray, optical, and radio observations of the massive galaxy cluster CIZA J0107.7+5408. We find that this system is a post-core-passage, dissociative, binary merger, with the optical galaxy density peaks of each subcluster leading their associated X-ray emission peaks. This separation occurs because the diffuse gas experiences ram pressure forces, while the effectively collisionless galaxies (and presumably their associated dark matter (DM) halos) do not. This system contains double-peaked diffuse radio emission, possibly a double radio relic with the relics lying along the merger axis and also leading the X-ray cores. We find evidence for amore » temperature peak associated with the SW relic, likely created by the same merger shock that is powering the relic radio emission in this region. Thus, this system is a relatively rare, clean example of a dissociative binary merger, which can in principle be used to place constraints on the self-interaction cross-section of DM. Low-frequency radio observations reveal ultra-steep spectrum diffuse radio emission that is not correlated with the X-ray, optical, or high-frequency radio emission. Here, we suggest that these sources are radio phoenixes, which are preexisting non-thermal particle populations that have been re-energized through adiabatic compression by the same merger shocks that power the radio relics. Finally, we place upper limits on inverse Compton emission from the SW radio relic.« less

Multi-wavelength Observations of the Dissociative Merger in the Galaxy Cluster CIZA J0107.7+5408

DOE PAGES

Randall, S. W.; Clarke, T. E.; Weeren, R. J. van; ...

2016-05-25

We present results based on X-ray, optical, and radio observations of the massive galaxy cluster CIZA J0107.7+5408. We find that this system is a post-core-passage, dissociative, binary merger, with the optical galaxy density peaks of each subcluster leading their associated X-ray emission peaks. This separation occurs because the diffuse gas experiences ram pressure forces, while the effectively collisionless galaxies (and presumably their associated dark matter (DM) halos) do not. This system contains double-peaked diffuse radio emission, possibly a double radio relic with the relics lying along the merger axis and also leading the X-ray cores. We find evidence for amore » temperature peak associated with the SW relic, likely created by the same merger shock that is powering the relic radio emission in this region. Thus, this system is a relatively rare, clean example of a dissociative binary merger, which can in principle be used to place constraints on the self-interaction cross-section of DM. Low-frequency radio observations reveal ultra-steep spectrum diffuse radio emission that is not correlated with the X-ray, optical, or high-frequency radio emission. Here, we suggest that these sources are radio phoenixes, which are preexisting non-thermal particle populations that have been re-energized through adiabatic compression by the same merger shocks that power the radio relics. Finally, we place upper limits on inverse Compton emission from the SW radio relic.« less

Two new confirmed massive relic galaxies: red nuggets in the present-day Universe

NASA Astrophysics Data System (ADS)

Ferré-Mateu, Anna; Trujillo, Ignacio; Martín-Navarro, Ignacio; Vazdekis, Alexandre; Mezcua, Mar; Balcells, Marc; Domínguez, Lilian

2017-05-01

We confirm two new local massive relic galaxies, I.e. untouched survivors of the early Universe massive population: Mrk 1216 and PGC 032873. Both show early and peaked formation events within very short time-scales (<1 Gyr) and thus old mean mass-weighted ages (˜13 Gyr). Their star formation histories remain virtually unchanged out to several effective radii, even when considering the steeper initial-mass-function values inferred out to ˜3 effective radii. Their morphologies, kinematics and density profiles are like those found in the z > 2 massive population, setting them apart from the typical z ˜ 0 massive early-type galaxies. We find that there seems to exist a degree of relic that is related to how far into the path, to become one of these typical z ˜ 0 massive galaxies, the compact relic has moved. This path is partly dictated by the environment the galaxy lives in. For galaxies in rich environments, such as the previously reported relic galaxy NGC 1277, the most extreme properties (e.g. sizes, short formation time-scales, larger supermassive black holes) are expected, while lower density environments will have galaxies with delayed and/or extended star formations, slightly larger sizes and not that extreme black hole masses. The confirmation of three relic galaxies up to a distance of 106 Mpc, implies a lower limit in the number density of these red nuggets in the local Universe of 6 × 10-7 Mpc3, which is within the theoretical expectations.

Relic neutralino surface at a 100 TeV collider

DOE PAGES

Bramante, Joseph; Fox, Patrick J.; Martin, Adam; ...

2015-03-11

We map the parameter space for minimal supersymmetric Standard Model neutralino dark matter which freezes out to the observed relic abundance, in the limit that all superpartners except the neutralinos and charginos are decoupled. In this space of relic neutralinos, we show the dominant dark matter annihilation modes, the mass splittings among the electroweakinos, direct detection rates, and collider cross sections. The mass difference between the dark matter and the next-to-lightest neutral and charged states is typically much less than electroweak gauge boson masses. With these small mass differences, the relic neutralino surface is accessible to a future 100 TeVmore » hadron collider, which can discover interneutralino mass splittings down to 1 GeV and thermal relic dark matter neutralino masses up to 1.5 TeV with a few inverse attobarns of luminosity. This coverage is a direct consequence of the increased collider energy: in the Standard Model events with missing transverse momentum in the TeV range have mostly hard electroweak radiation, distinct from the soft radiation shed in compressed electroweakino decays. As a result, we exploit this kinematic feature in final states including photons and leptons, tailored to the 100 TeV collider environment.« less

Symmetry States of the physical space: an expanded reference frame for understanding human consciousness.

PubMed

Manek, Nisha J

2012-01-01

A remarkable phenomenon is taking place around the globe, one that I have been fortunate enough to witness and in which to participate. The relics of the historical Buddha, also known as Siddhartha or Shakyamuni Buddha, still survive today over 2500 years since his enlightenment, and, for the first time in history, are traveling throughout the world. In common Buddhist practice, relics are highly venerated and treasured remains of realized Masters. It is very rare for relics to travel from city to city and be available for viewing by the general public. The Buddha relic tour is demonstrating that a direct experience of the spiritual state is not mysterious, nor is it for a select few. The spiritual state, here defined as a universal theme of unconditional love, is a component of human evolutionary unfoldment, a process through which thousands of human beings have passed, and through which thousands more will pass. We are "waking up" as a species. Consequently, more information is required about this transformation of human consciousness. The Buddha relics offer us a priceless means by which we can obtain a richer perspective about the nature of human consciousness, spiritual realities such as love, and ultimately understanding ourselves.

Quark soup al dente: applied superstring theory

NASA Astrophysics Data System (ADS)

Myers, R. C.; Vázquez, S. E.

2008-06-01

In recent years, experiments have discovered an exotic new state of matter known as the strongly coupled quark gluon plasma (sQGP). At present, it seems that standard theoretical tools, such as perturbation theory and lattice gauge theory, are poorly suited to understand this new phase. However, recent progress in superstring theory has provided us with a theoretical laboratory for studying very similar systems of strongly interacting hot non-Abelian plasmas. This surprising new perspective extracts the fluid properties of the sQGP from physical processes in a black hole spacetime. Hence we may find the answers to difficult particle physics questions about the sQGP from straightforward calculations in classical general relativity.

MC2: Subaru and Hubble Space Telescope Weak-lensing Analysis of the Double Radio Relic Galaxy Cluster PLCK G287.0+32.9

NASA Astrophysics Data System (ADS)

Finner, Kyle; Jee, M. James; Golovich, Nathan; Wittman, David; Dawson, William; Gruen, Daniel; Koekemoer, Anton M.; Lemaux, Brian C.; Seitz, Stella

2017-12-01

The second most significant detection of the Planck Sunyaev‑Zel’dovich survey, PLCK G287.0+32.9 (z = 0.385), boasts two similarly bright radio relics and a radio halo. One radio relic is located ∼ 400 {kpc} NW of the X-ray peak and the other ∼ 2.8 Mpc to the SE. This large difference suggests that a complex merging scenario is required. A key missing puzzle for the merging scenario reconstruction is the underlying dark matter distribution in high resolution. We present a joint Subaru Telescope and Hubble Space Telescope weak-lensing analysis of the cluster. Our analysis shows that the mass distribution features four significant substructures. Of the substructures, a primary cluster of mass {M}200{{c}}={1.59}-0.22+0.25× {10}15 {h}70-1 {M}ȯ dominates the weak-lensing signal. This cluster is likely to be undergoing a merger with one (or more) subcluster whose mass is approximately a factor of 10 lower. One candidate is the subcluster of mass {M}200{{c}}={1.16}-0.13+0.15× {10}14 {h}70-1 {M}ȯ located ∼ 400 {kpc} to the SE. The location of this subcluster suggests that its interaction with the primary cluster could be the source of the NW radio relic. Another subcluster is detected ∼ 2 Mpc to the SE of the X-ray peak with mass {M}200{{c}}={1.68}-0.20+0.22× {10}14 {h}70-1 {M}ȯ . This SE subcluster is in the vicinity of the SE radio relic and may have created the SE radio relic during a past merger with the primary cluster. The fourth subcluster, {M}200{{c}}={1.87}-0.22+0.24× {10}14 {h}70-1 {M}ȯ , is NW of the X-ray peak and beyond the NW radio relic.

Chandra and JVLA Observations of HST Frontier Fields Cluster MACS J0717.5+3745

DOE PAGES

van Weeren, R. J.; Ogrean, G. A.; Jones, C.; ...

2017-01-31

To investigate the relationship between thermal and non-thermal components in merger galaxy clusters, we present deep JVLA and Chandra observations of the HST Frontier Fields cluster MACS J0717.5+3745. The Chandra image shows a complex merger event, with at least four components belonging to different merging subclusters. Northwest of the cluster, ~0.7 Mpc from the center, there is a ram-pressure-stripped core that appears to have traversed the densest parts of the cluster after entering the intracluster medium (ICM) from the direction of a galaxy filament to the southeast. Here, we detect a density discontinuity north-northeast of this core, which we speculatemore » is associated with a cold front. Our radio images reveal new details for the complex radio relic and radio halo in this cluster. In addition, we discover several new filamentary radio sources with sizes of 100–300 kpc. A few of these seem to be connected to the main radio relic, while others are either embedded within the radio halo or projected onto it. A narrow-angled-tailed (NAT) radio galaxy, a cluster member, is located at the center of the radio relic. The steep spectrum tails of this active galactic nucleus lead into the large radio relic where the radio spectrum flattens again. This morphological connection between the NAT radio galaxy and relic provides evidence for re-acceleration (revival) of fossil electrons. The presence of hot ≳20 keV ICM gas detected by Chandra near the relic location provides additional support for this re-acceleration scenario.« less

Chandra and JVLA Observations of HST Frontier Fields Cluster MACS J0717.5+3745

NASA Astrophysics Data System (ADS)

van Weeren, R. J.; Ogrean, G. A.; Jones, C.; Forman, W. R.; Andrade-Santos, F.; Pearce, Connor J. J.; Bonafede, A.; Brüggen, M.; Bulbul, E.; Clarke, T. E.; Churazov, E.; David, L.; Dawson, W. A.; Donahue, M.; Goulding, A.; Kraft, R. P.; Mason, B.; Merten, J.; Mroczkowski, T.; Nulsen, P. E. J.; Rosati, P.; Roediger, E.; Randall, S. W.; Sayers, J.; Umetsu, K.; Vikhlinin, A.; Zitrin, A.

2017-02-01

To investigate the relationship between thermal and non-thermal components in merger galaxy clusters, we present deep JVLA and Chandra observations of the HST Frontier Fields cluster MACS J0717.5+3745. The Chandra image shows a complex merger event, with at least four components belonging to different merging subclusters. Northwest of the cluster, ˜0.7 Mpc from the center, there is a ram-pressure-stripped core that appears to have traversed the densest parts of the cluster after entering the intracluster medium (ICM) from the direction of a galaxy filament to the southeast. We detect a density discontinuity north-northeast of this core, which we speculate is associated with a cold front. Our radio images reveal new details for the complex radio relic and radio halo in this cluster. In addition, we discover several new filamentary radio sources with sizes of 100-300 kpc. A few of these seem to be connected to the main radio relic, while others are either embedded within the radio halo or projected onto it. A narrow-angled-tailed (NAT) radio galaxy, a cluster member, is located at the center of the radio relic. The steep spectrum tails of this active galactic nucleus lead into the large radio relic where the radio spectrum flattens again. This morphological connection between the NAT radio galaxy and relic provides evidence for re-acceleration (revival) of fossil electrons. The presence of hot ≳20 keV ICM gas detected by Chandra near the relic location provides additional support for this re-acceleration scenario.

On the absence of radio haloes in clusters with double relics

NASA Astrophysics Data System (ADS)

Bonafede, A.; Cassano, R.; Brüggen, M.; Ogrean, G. A.; Riseley, C. J.; Cuciti, V.; de Gasperin, F.; Golovich, N.; Kale, R.; Venturi, T.; van Weeren, R. J.; Wik, D. R.; Wittman, D.

2017-09-01

Pairs of radio relics are believed to form during cluster mergers, and are best observed when the merger occurs in the plane of the sky. Mergers can also produce radio haloes, through complex processes likely linked to turbulent re-acceleration of cosmic ray electrons. However, only some clusters with double relics also show a radio halo. Here, we present a novel method to derive upper limits on the radio halo emission, and analyse archival X-ray Chandra data, as well as galaxy velocity dispersions and lensing data, in order to understand the key parameter that switches on radio halo emission. We place upper limits on the halo power below the P1.4 GHz-M500 correlation for some clusters, confirming that clusters with double relics have different radio properties. Computing X-ray morphological indicators, we find that clusters with double relics are associated with the most disturbed clusters. We also investigate the role of different mass-ratios and time-since-merger. Data do not indicate that the merger mass-ratio has an impact on the presence or absence of radio haloes (the null hypothesis that the clusters belong to the same group cannot be rejected). However, the data suggest that the absence of radio haloes could be associated with early and late mergers, but the sample is too small to perform a statistical test. Our study is limited by the small number of clusters with double relics. Future surveys with LOFAR, ASKAP, MeerKat and SKA will provide larger samples to better address this issue.

Chandra and JVLA Observations of HST Frontier Fields Cluster MACS J0717.5+3745

DOE Office of Scientific and Technical Information (OSTI.GOV)

Van Weeren, R. J.; Jones, C.; Forman, W. R.

To investigate the relationship between thermal and non-thermal components in merger galaxy clusters, we present deep JVLA and Chandra observations of the HST Frontier Fields cluster MACS J0717.5+3745. The Chandra image shows a complex merger event, with at least four components belonging to different merging subclusters. Northwest of the cluster, ∼0.7 Mpc from the center, there is a ram-pressure-stripped core that appears to have traversed the densest parts of the cluster after entering the intracluster medium (ICM) from the direction of a galaxy filament to the southeast. We detect a density discontinuity north-northeast of this core, which we speculate ismore » associated with a cold front. Our radio images reveal new details for the complex radio relic and radio halo in this cluster. In addition, we discover several new filamentary radio sources with sizes of 100–300 kpc. A few of these seem to be connected to the main radio relic, while others are either embedded within the radio halo or projected onto it. A narrow-angled-tailed (NAT) radio galaxy, a cluster member, is located at the center of the radio relic. The steep spectrum tails of this active galactic nucleus lead into the large radio relic where the radio spectrum flattens again. This morphological connection between the NAT radio galaxy and relic provides evidence for re-acceleration (revival) of fossil electrons. The presence of hot ≳20 keV ICM gas detected by Chandra near the relic location provides additional support for this re-acceleration scenario.« less

Chandra and JVLA Observations of HST Frontier Fields Cluster MACS J0717.5+3745

DOE Office of Scientific and Technical Information (OSTI.GOV)

van Weeren, R. J.; Ogrean, G. A.; Jones, C.

To investigate the relationship between thermal and non-thermal components in merger galaxy clusters, we present deep JVLA and Chandra observations of the HST Frontier Fields cluster MACS J0717.5+3745. The Chandra image shows a complex merger event, with at least four components belonging to different merging subclusters. Northwest of the cluster, ~0.7 Mpc from the center, there is a ram-pressure-stripped core that appears to have traversed the densest parts of the cluster after entering the intracluster medium (ICM) from the direction of a galaxy filament to the southeast. Here, we detect a density discontinuity north-northeast of this core, which we speculatemore » is associated with a cold front. Our radio images reveal new details for the complex radio relic and radio halo in this cluster. In addition, we discover several new filamentary radio sources with sizes of 100–300 kpc. A few of these seem to be connected to the main radio relic, while others are either embedded within the radio halo or projected onto it. A narrow-angled-tailed (NAT) radio galaxy, a cluster member, is located at the center of the radio relic. The steep spectrum tails of this active galactic nucleus lead into the large radio relic where the radio spectrum flattens again. This morphological connection between the NAT radio galaxy and relic provides evidence for re-acceleration (revival) of fossil electrons. The presence of hot ≳20 keV ICM gas detected by Chandra near the relic location provides additional support for this re-acceleration scenario.« less

Type IIB supergravity solution for the T-dual of the η-deformed AdS 5 × S 5 superstring

NASA Astrophysics Data System (ADS)

Hoare, B.; Tseytlin, A. A.

2015-10-01

We find an exact type IIB supergravity solution that represents a one-parameter deformation of the T-dual of the AdS 5 × S 5 background (with T-duality applied in all 6 abelian bosonic isometric directions). The non-trivial fields are the metric, dilaton and RR 5-form only. The latter has remarkably simple "undeformed" form when written in terms of a "deformation-rotated" vielbein basis. An unusual feature of this solution is that the dilaton contains a linear dependence on the isometric coordinates of the metric precluding a straightforward reversal of T-duality. If we still formally dualize back, we find exactly the metric, B-field and product of dilaton with RR field strengths as recently extracted from the η-deformed AdS 5 × S 5 superstring action in arXiv:1507.04239. We also discuss similar solutions for deformed AdS n × S n backgrounds with n = 2 , 3. In the η → i limit we demonstrate that all these backgrounds can be interpreted as special limits of gauged WZW models and are also related to (a limit of) the Pohlmeyer-reduced models of the AdS n × S n superstrings.

Long-lived stops in MSSM scenarios with a neutralino LSP

NASA Astrophysics Data System (ADS)

Johansen, M.; Edsjö, J.; Hellman, S.; Milstead, D.

2010-08-01

This work investigates the possibility of a long-lived stop squark in supersymmetric models with the neutralino as the lightest supersymmetric particle (LSP). We study the implications of meta-stable stops on the sparticle mass spectra and the dark matter density. We find that in order to obtain a sufficiently long stop lifetime so as to be observable as a stable R-hadron at an LHC experiment, we need to fine tune the mass degeneracy between the stop and the LSP considerably. This increases the stop-neutralino co-anihilation cross section, leaving the neutralino relic density lower than what is expected from the WMAP results for stop masses ≲1.5 TeV/ c 2. However, if such scenarios are realised in nature we demonstrate that the long-lived stops will be produced at the LHC and that stop-based R-hadrons with masses up to 1 TeV/c2 can be detected after one year of running at design luminosity.

A thiamin-utilizing ribozyme decarboxylates a pyruvate-like substrate

NASA Astrophysics Data System (ADS)

Cernak, Paul; Sen, Dipankar

2013-11-01

Vitamins are hypothesized to be relics of an RNA world, and were probably participants in RNA-mediated primordial metabolism. If catalytic RNAs, or ribozymes, could harness vitamin cofactors to aid their function in a manner similar to protein enzymes, it would enable them to catalyse a much larger set of chemical reactions. The cofactor thiamin diphosphate, a derivative of vitamin B1 (thiamin), is used by enzymes to catalyse difficult metabolic reactions, including decarboxylation of stable α-keto acids such as pyruvate. Here, we report a ribozyme that uses free thiamin to decarboxylate a pyruvate-based suicide substrate (LnkPB). Thiamin conjugated to biotin was used to isolate catalytic individuals from a pool of random-sequence RNAs attached to LnkPB. Analysis of a stable guanosine adduct obtained via digestion of an RNA sequence (clone dc4) showed the expected decarboxylation product. The discovery of a prototypic thiamin-utilizing ribozyme has implications for the role of RNA in orchestrating early metabolic cycles.

a Method of 3d Measurement and Reconstruction for Cultural Relics in Museums

NASA Astrophysics Data System (ADS)

Zheng, S.; Zhou, Y.; Huang, R.; Zhou, L.; Xu, X.; Wang, C.

2012-07-01

Three-dimensional measurement and reconstruction during conservation and restoration of cultural relics have become an essential part of a modem museum regular work. Although many kinds of methods including laser scanning, computer vision and close-range photogrammetry have been put forward, but problems still exist, such as contradiction between cost and good result, time and fine effect. Aimed at these problems, this paper proposed a structure-light based method for 3D measurement and reconstruction of cultural relics in museums. Firstly, based on structure-light principle, digitalization hardware has been built and with its help, dense point cloud of cultural relics' surface can be easily acquired. To produce accurate 3D geometry model from point cloud data, multi processing algorithms have been developed and corresponding software has been implemented whose functions include blunder detection and removal, point cloud alignment and merge, 3D mesh construction and simplification. Finally, high-resolution images are captured and the alignment of these images and 3D geometry model is conducted and realistic, accurate 3D model is constructed. Based on such method, a complete system including hardware and software are built. Multi-kinds of cultural relics have been used to test this method and results prove its own feature such as high efficiency, high accuracy, easy operation and so on.

Electromagnetic characterization of conformal antennas

NASA Technical Reports Server (NTRS)

Volakis, John L.; Kempel, Leo C.; Alexanian, Angelos; Jin, J. M.; Yu, C. L.; Woo, Alex C.

1992-01-01

The ultimate objective of this project is to develop a new technique which permits an accurate simulation of microstrip patch antennas or arrays with various feed, superstrate and/or substrate configurations residing in a recessed cavity whose aperture is planar, cylindrical or otherwise conformed to the substructure. The technique combines the finite element and boundary integral methods to formulate a system suitable for solution via the conjugate gradient method in conjunction with the fast Fourier transform. The final code is intended to compute both scattering and radiation patterns of the structure with an affordable memory demand. With upgraded capabilities, the four included papers examined the radar cross section (RCS), input impedance, gain, and resonant frequency of several rectangular configurations using different loading and substrate/superstrate configurations.

Nondecoupling of maximal supergravity from the superstring.

PubMed

Green, Michael B; Ooguri, Hirosi; Schwarz, John H

2007-07-27

We consider the conditions necessary for obtaining perturbative maximal supergravity in d dimensions as a decoupling limit of type II superstring theory compactified on a (10-d) torus. For dimensions d=2 and d=3, it is possible to define a limit in which the only finite-mass states are the 256 massless states of maximal supergravity. However, in dimensions d>or=4, there are infinite towers of additional massless and finite-mass states. These correspond to Kaluza-Klein charges, wound strings, Kaluza-Klein monopoles, or branes wrapping around cycles of the toroidal extra dimensions. We conclude that perturbative supergravity cannot be decoupled from string theory in dimensions>or=4. In particular, we conjecture that pure N=8 supergravity in four dimensions is in the Swampland.

Expanding (3+1)-dimensional universe from a lorentzian matrix model for superstring theory in (9+1) dimensions.

PubMed

Kim, Sang-Woo; Nishimura, Jun; Tsuchiya, Asato

2012-01-06

We reconsider the matrix model formulation of type IIB superstring theory in (9+1)-dimensional space-time. Unlike the previous works in which the Wick rotation was used to make the model well defined, we regularize the Lorentzian model by introducing infrared cutoffs in both the spatial and temporal directions. Monte Carlo studies reveal that the two cutoffs can be removed in the large-N limit and that the theory thus obtained has no parameters other than one scale parameter. Moreover, we find that three out of nine spatial directions start to expand at some "critical time," after which the space has SO(3) symmetry instead of SO(9).

The next generation CdTe technology- Substrate foil based solar cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ferekides, Chris

The main objective of this project was the development of one of the most promising Photovoltaic (PV) materials CdTe into a versatile, cost effective, and high throughput technology, by demonstrating substrate devices on foil substrates using high throughput fabrication conditions. The typical CdTe cell is of the superstrate configuration where the solar cell is fabricated on a glass superstrate by the sequential deposition of a TCO, n-type heterojunction partner, p-CdTe absorber, and back contact. Large glass modules are heavy and present significant challenges during manufacturing (uniform heating, etc.). If a substrate CdTe cell could be developed (the main goal ofmore » this project) a roll-to-toll high throughput technology could be developed.« less

LOFAR, VLA, and Chandra observations of the Toothbrush Galaxy Cluster

DOE PAGES

van Weeren, R. J.; Brunetti, G.; Bruggen, M.; ...

2016-02-22

We present deep LOFAR observations between 120 {181 MHz of the `Toothbrush' (RX J0603.3+4214), a cluster that contains one of the brightest radio relic sources known. Our LOFAR observations exploit a new and novel calibration scheme to probe 10 times deeper than any previous study in this relatively unexplored part of the spectrum. The LOFAR observations, when combined with VLA, GMRT, and Chandra X-ray data, provide new information about the nature of cluster merger shocks and their role in re-accelerating relativistic particles. We derive a spectral index of α = -0:8±0:1 at the northern edge of the main radio relic,more » steepening towards the south to α ≈ -2. The spectral index of the radio halo is remarkably uniform (α = -1:16, with an intrinsic scatter of ≤ 0:04). The observed radio relic spectral index gives a Mach number of M = 2:8 +0:5 -0:3, assuming diffusive shock acceleration (DSA). However, the gas density jump at the northern edge of the large radio relic implies a much weaker shock (M≈1:2, with an upper limit ofM≈1:5). The discrepancy between the Mach numbers calculated from the radio and X-rays can be explained if either (i) the relic traces a complex shock surface along the line of sight, or (ii) if the radio relic emission is produced by a re-accelerated population of fossil particles from a radio galaxy. Our results highlight the need for additional theoretical work and numerical simulations of particle acceleration and re-acceleration at cluster merger shocks.« less

Implications for the Cosmological Landscape: Can Thermal Inputs from a Prior Universe Account for Relic Graviton Production?

NASA Astrophysics Data System (ADS)

Beckwith, A. W.

2008-01-01

Sean Carroll's pre-inflation state of low temperature-low entropy provides a bridge between two models with different predictions. The Wheeler-de Witt equation provides thermal input into today's universe for graviton production. Also, brane world models by Sundrum allow low entropy conditions, as given by Carroll & Chen (2005). Moreover, this paper answers the question of how to go from a brane world model to the 10 to the 32 power Kelvin conditions stated by Weinberg in 1972 as necessary for the initiation of quantum gravity processes. This is a way of getting around the fact CMBR is cut off at a red shift of z = 1100. This paper discusses the difference in values of the upper bound of the cosmological constant between a large upper bound predicated for a temperature dependent vacuum energy predicted by Park (2002), and the much lower bound predicted by Barvinsky (2006). with the difference in values in vacuum energy contributing to relic graviton production. This paper claims that this large thermal influx, with a high initial cosmological constant and a large region of space for relic gravitons interacting with space-time up to the z = 1100 CMBR observational limit are interlinked processes delineated in the Lloyd (2002) analogy of the universe as a quantum computing system. Finally, the paper claims that linking a shrinking prior universe via a worm hole solution for a pseudo time dependent Wheeler-De Witt equation permits graviton generation as thermal input from the prior universe, transferred instantaneously to relic inflationary conditions today. The existence of a wormhole is presented as a necessary condition for relic gravitons. Proving the sufficiency of the existence of a worm hole for relic gravitons is a future project.

VLA Radio Observations of the HST Frontier Fields Cluster Abell 2744: The Discovery of New Radio Relics

NASA Astrophysics Data System (ADS)

Pearce, C. J. J.; van Weeren, R. J.; Andrade-Santos, F.; Jones, C.; Forman, W. R.; Brüggen, M.; Bulbul, E.; Clarke, T. E.; Kraft, R. P.; Medezinski, E.; Mroczkowski, T.; Nonino, M.; Nulsen, P. E. J.; Randall, S. W.; Umetsu, K.

2017-08-01

Cluster mergers leave distinct signatures in the intracluster medium (ICM) in the form of shocks and diffuse cluster radio sources that provide evidence for the acceleration of relativistic particles. However, the physics of particle acceleration in the ICM is still not fully understood. Here we present new 1-4 GHz Jansky Very Large Array (VLA) and archival Chandra observations of the HST Frontier Fields Cluster Abell 2744. In our new VLA images, we detect the previously known ˜2.1 Mpc radio halo and ˜1.5 Mpc radio relic. We carry out a radio spectral analysis from which we determine the relic’s injection spectral index to be {α }{inj}=-1.12+/- 0.19. This corresponds to a shock Mach number of { M }={2.05}-0.19+0.31 under the assumption of diffusive shock acceleration. We also find evidence for spectral steepening in the post-shock region. We do not find evidence for a significant correlation between the radio halo’s spectral index and ICM temperature. In addition, we observe three new polarized diffuse sources and determine two of these to be newly discovered giant radio relics. These two relics are located in the southeastern and northwestern outskirts of the cluster. The corresponding integrated spectral indices measure -1.81 ± 0.26 and -0.63 ± 0.21 for the SE and NW relics, respectively. From an X-ray surface brightness profile we also detect a possible density jump of R={1.39}-0.22+0.34 co-located with the newly discovered SE relic. This density jump would correspond to a shock front Mach number of { M }={1.26}-0.15+0.25.

A Nearby Ancient “Relic Galaxy” on This Week @NASA – March 16, 2018

NASA Image and Video Library

2018-03-16

Uncovering a relic galaxy in our own cosmic backyard, preparing for launch to the space station, and honoring the legacy of Stephen Hawking – a few of the stories to tell you about – This Week at NASA!

A Study about the 3S-based Great Ruins Monitoring and Early-warning System

NASA Astrophysics Data System (ADS)

Xuefeng, W.; Zhongyuan, H.; Gongli, L.; Li, Z.

2015-08-01

Large-scale urbanization construction and new countryside construction, frequent natural disasters, and natural corrosion pose severe threat to the great ruins. It is not uncommon that the cultural relics are damaged and great ruins are occupied. Now the ruins monitoring mainly adopt general monitoring data processing system which can not effectively exert management, display, excavation analysis and data sharing of the relics monitoring data. Meanwhile those general software systems require layout of large number of devices or apparatuses, but they are applied to small-scope relics monitoring only. Therefore, this paper proposes a method to make use of the stereoscopic cartographic satellite technology to improve and supplement the great ruins monitoring index system and combine GIS and GPS to establish a highly automatic, real-time and intelligent great ruins monitoring and early-warning system in order to realize collection, processing, updating, spatial visualization, analysis, distribution and sharing of the monitoring data, and provide scientific and effective data for the relics protection, scientific planning, reasonable development and sustainable utilization.

IR and py/GC/MS examination of amber relics excavated from 6th century royal tomb in Korean Peninsula.

PubMed

Park, Jongseo; Yun, Eunyoung; Kang, Hyungtae; Ahn, Jooyoung; Kim, Gyuho

2016-08-05

Relics of amber were excavated from King Muryeong's tomb constructed in the 6th century on the Korean peninsula. To estimate the provenance, FTIR (Fourier transform infrared spectroscopy) and py/GC/MS (pyrolysis/gas chromatography/mass spectrometry) analysis were utilized. The reference Baltic amber sample was also analyzed with the same method for comparison. The relics were confirmed to be amber from the FTIR analysis where an absorption band near 1150cm(-1), characteristic one in Baltic amber, was also observed. In py/GC/MS analysis, pyrolyzed products like butanedioic acid and dehydroabietic acid, known constituents of amber, were observed. In addition, d-fenchyl alcohol, camphor, borneol and butanedioic acid, typical constituents of Baltic amber, were observed in some samples. From this, it appears that some of relics were made from Baltic amber and that Baltic amber was transported to the Korean peninsula in the time of tomb construction. Copyright © 2016 Elsevier B.V. All rights reserved.

MC 2: Subaru and Hubble Space Telescope Weak-lensing Analysis of the Double Radio Relic Galaxy Cluster PLCK G287.0+32.9

DOE Office of Scientific and Technical Information (OSTI.GOV)

Finner, Kyle; Jee, M. James; Golovich, Nathan

The second most significant detection of the Planck Sunyaev-Zel'dovich survey, PLCK G287.0+32.9 (z = 0.385), boasts two similarly bright radio relics and a radio halo. One radio relic is locatedmore » $$\\sim 400\\,\\mathrm{kpc}$$ NW of the X-ray peak and the other $$\\sim 2.8$$ Mpc to the SE. This large difference suggests that a complex merging scenario is required. A key missing puzzle for the merging scenario reconstruction is the underlying dark matter distribution in high resolution. Here, we present a joint Subaru Telescope and Hubble Space Telescope weak-lensing analysis of the cluster. Our analysis shows that the mass distribution features four significant substructures. Of the substructures, a primary cluster of mass $${M}_{200{\\rm{c}}}={1.59}_{-0.22}^{+0.25}\\times {10}^{15}\\ {h}_{70}^{-1}\\ {M}_{\\odot }$$ dominates the weak-lensing signal. This cluster is likely to be undergoing a merger with one (or more) subcluster whose mass is approximately a factor of 10 lower. One candidate is the subcluster of mass $${M}_{200{\\rm{c}}}={1.16}_{-0.13}^{+0.15}\\times {10}^{14}\\ {h}_{70}^{-1}\\ {M}_{\\odot }$$ located $$\\sim 400\\,\\mathrm{kpc}$$ to the SE. The location of this subcluster suggests that its interaction with the primary cluster could be the source of the NW radio relic. Another subcluster is detected $$\\sim 2$$ Mpc to the SE of the X-ray peak with mass $${M}_{200{\\rm{c}}}={1.68}_{-0.20}^{+0.22}\\times {10}^{14}\\ {h}_{70}^{-1}\\ {M}_{\\odot }$$. This SE subcluster is in the vicinity of the SE radio relic and may have created the SE radio relic during a past merger with the primary cluster. The fourth subcluster, $${M}_{200{\\rm{c}}}={1.87}_{-0.22}^{+0.24}\\times {10}^{14}\\ {h}_{70}^{-1}\\ {M}_{\\odot }$$, is NW of the X-ray peak and beyond the NW radio relic.« less

MC 2: Subaru and Hubble Space Telescope Weak-lensing Analysis of the Double Radio Relic Galaxy Cluster PLCK G287.0+32.9

DOE PAGES

Finner, Kyle; Jee, M. James; Golovich, Nathan; ...

2017-12-11

The second most significant detection of the Planck Sunyaev-Zel'dovich survey, PLCK G287.0+32.9 (z = 0.385), boasts two similarly bright radio relics and a radio halo. One radio relic is locatedmore » $$\\sim 400\\,\\mathrm{kpc}$$ NW of the X-ray peak and the other $$\\sim 2.8$$ Mpc to the SE. This large difference suggests that a complex merging scenario is required. A key missing puzzle for the merging scenario reconstruction is the underlying dark matter distribution in high resolution. Here, we present a joint Subaru Telescope and Hubble Space Telescope weak-lensing analysis of the cluster. Our analysis shows that the mass distribution features four significant substructures. Of the substructures, a primary cluster of mass $${M}_{200{\\rm{c}}}={1.59}_{-0.22}^{+0.25}\\times {10}^{15}\\ {h}_{70}^{-1}\\ {M}_{\\odot }$$ dominates the weak-lensing signal. This cluster is likely to be undergoing a merger with one (or more) subcluster whose mass is approximately a factor of 10 lower. One candidate is the subcluster of mass $${M}_{200{\\rm{c}}}={1.16}_{-0.13}^{+0.15}\\times {10}^{14}\\ {h}_{70}^{-1}\\ {M}_{\\odot }$$ located $$\\sim 400\\,\\mathrm{kpc}$$ to the SE. The location of this subcluster suggests that its interaction with the primary cluster could be the source of the NW radio relic. Another subcluster is detected $$\\sim 2$$ Mpc to the SE of the X-ray peak with mass $${M}_{200{\\rm{c}}}={1.68}_{-0.20}^{+0.22}\\times {10}^{14}\\ {h}_{70}^{-1}\\ {M}_{\\odot }$$. This SE subcluster is in the vicinity of the SE radio relic and may have created the SE radio relic during a past merger with the primary cluster. The fourth subcluster, $${M}_{200{\\rm{c}}}={1.87}_{-0.22}^{+0.24}\\times {10}^{14}\\ {h}_{70}^{-1}\\ {M}_{\\odot }$$, is NW of the X-ray peak and beyond the NW radio relic.« less

75 FR 53013 - Culturally Significant Objects Imported for Exhibition Determinations: “Treasures of Heaven...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-08-30

... DEPARTMENT OF STATE [Public Notice 7138] Culturally Significant Objects Imported for Exhibition Determinations: ``Treasures of Heaven: Saints, Relics, and Devotion in Medieval Europe'' SUMMARY: Notice is..., Relics, and Devotion in Medieval Europe,'' imported from abroad for temporary exhibition within the...

27 CFR 478.26 - Curio and relic determination.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 27 Alcohol, Tobacco Products and Firearms 3 2013-04-01 2013-04-01 false Curio and relic determination. 478.26 Section 478.26 Alcohol, Tobacco Products, and Firearms BUREAU OF ALCOHOL, TOBACCO, FIREARMS, AND EXPLOSIVES, DEPARTMENT OF JUSTICE FIREARMS AND AMMUNITION COMMERCE IN FIREARMS AND AMMUNITION...

27 CFR 478.26 - Curio and relic determination.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 27 Alcohol, Tobacco Products and Firearms 3 2011-04-01 2010-04-01 true Curio and relic determination. 478.26 Section 478.26 Alcohol, Tobacco Products, and Firearms BUREAU OF ALCOHOL, TOBACCO, FIREARMS, AND EXPLOSIVES, DEPARTMENT OF JUSTICE FIREARMS AND AMMUNITION COMMERCE IN FIREARMS AND AMMUNITION...

27 CFR 478.26 - Curio and relic determination.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 27 Alcohol, Tobacco Products and Firearms 3 2014-04-01 2014-04-01 false Curio and relic determination. 478.26 Section 478.26 Alcohol, Tobacco Products, and Firearms BUREAU OF ALCOHOL, TOBACCO, FIREARMS, AND EXPLOSIVES, DEPARTMENT OF JUSTICE FIREARMS AND AMMUNITION COMMERCE IN FIREARMS AND AMMUNITION...

27 CFR 478.26 - Curio and relic determination.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 27 Alcohol, Tobacco Products and Firearms 3 2012-04-01 2010-04-01 true Curio and relic determination. 478.26 Section 478.26 Alcohol, Tobacco Products, and Firearms BUREAU OF ALCOHOL, TOBACCO, FIREARMS, AND EXPLOSIVES, DEPARTMENT OF JUSTICE FIREARMS AND AMMUNITION COMMERCE IN FIREARMS AND AMMUNITION...

27 CFR 478.26 - Curio and relic determination.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 27 Alcohol, Tobacco Products and Firearms 3 2010-04-01 2010-04-01 false Curio and relic determination. 478.26 Section 478.26 Alcohol, Tobacco Products, and Firearms BUREAU OF ALCOHOL, TOBACCO, FIREARMS, AND EXPLOSIVES, DEPARTMENT OF JUSTICE FIREARMS AND AMMUNITION COMMERCE IN FIREARMS AND AMMUNITION...

Explaining the DAMPE e+e- excess using the Higgs triplet model with a vector dark matter

NASA Astrophysics Data System (ADS)

Chen, Chuan-Hung; Chiang, Cheng-Wei; Nomura, Takaaki

2018-03-01

We explain the e+e- excess observed by the DAMPE Collaboration using a dark matter model based upon the Higgs triplet model and an additional hidden S U (2 )X gauge symmetry. Two of the S U (2 )X gauge bosons are stable due to a residual discrete symmetry and serve as the dark matter candidate. We search the parameter space for regions that can explain the observed relic abundance, and compute the flux of e+e- coming from a nearby dark matter subhalo. With the inclusion of background cosmic rays, we show that the model can render a good fit to the entire energy spectrum covering the AMS-02, Fermi-LAT, CALET and DAMPE data.

Buried nanoantenna arrays: versatile antireflection coating.

PubMed

Kabiri, Ali; Girgis, Emad; Capasso, Federico

2013-01-01

Reflection is usually a detrimental phenomenon in many applications such as flat-panel-displays, solar cells, photodetectors, infrared sensors, and lenses. Thus far, to control and suppress the reflection from a substrate, numerous techniques including dielectric interference coatings, surface texturing, adiabatic index matching, and scattering from plasmonic nanoparticles have been investigated. A new technique is demonstrated to manage and suppress reflection from lossless and lossy substrates. It provides a wider flexibility in design versus previous methods. Reflection from a surface can be suppressed over a narrowband, wideband, or multiband frequency range. The antireflection can be dependent or independent of the incident wave polarization. Moreover, antireflection at a very wide incidence angle can be attained. The reflection from a substrate is controlled by a buried nanoantenna array, a structure composed of (1) a subwavelength metallic array and (2) a dielectric cover layer referred to as a superstrate. The material properties and thickness of the superstrate and nanoantennas' geometry and periodicity control the phase and intensity of the wave circulating inside the superstrate cavity. A minimum reflectance of 0.02% is achieved in various experiments in the mid-infrared from a silicon substrate. The design can be integrated in straightforward way in optical devices. The proposed structure is a versatile AR coating to optically impedance matches any substrate to free space in selected any narrow and broadband spectral response across the entire visible and infrared spectrum.

Thin film module development

NASA Technical Reports Server (NTRS)

Jester, T.

1985-01-01

The design of ARCO Solar, Inc.'s Genesis G100 photovoltaic module was driven by several criteria, including environmental stability (both electrical and mechanical), consumer aesthetics, low materials costs, and manufacturing ease. The module circuitry is designed as a 12 volt battery charger, using monolithic patterning techniques on a glass superstrate. This patterning and interconnect method proves amenable to high volume, low cost production throughput, and the use of glass serves the dual role of handling ease and availability. The mechanical design of the module centers on environmental stability. Packaging of the glass superstrate circuit must provide good resistance to thermal and humidity exposure along with hi-pot insulation and hailstone impact resistance. The options considered are given. Ethylene vinyl acetate (EVA) is chosen as the pottant material for its excellent weatherability.

Observations and Modeling of Merging Galaxy Clusters

NASA Astrophysics Data System (ADS)

Golovich, Nathan Ryan

Context: Galaxy clusters grow hierarchically with continuous accretion bookended by major merging events that release immense gravitational potential energy (as much as ˜1065 erg). This energy creates an environment for rich astrophysics. Precise measurements of the dark matter halo, intracluster medium, and galaxy population have resulted in a number of important results including dark matter constraints and explanations of the generation of cosmic rays. However, since the timescale of major mergers (˜several Gyr) relegates observations of individual systems to mere snapshots, these results are difficult to understand under a consistent dynamical framework. While computationally expensive simulations are vital in this regard, the vastness of parameter space has necessitated simulations of idealized mergers that are unlikely to capture the full richness. Merger speeds, geometries, and timescales each have a profound consequential effect, but even these simple dynamical properties of the mergers are often poorly understood. A method to identify and constrain the best systems for probing the rich astrophysics of merging clusters is needed. Such a method could then be utilized to prioritize observational follow up and best inform proper exploration of dynamical phase space. Task: In order to identify and model a large number of systems, in this dissertation, we compile an ensemble of major mergers each containing radio relics. We then complete a pan-chromatic study of these 29 systems including wide field optical photometry, targeted optical spectroscopy of member galaxies, radio, and X-ray observations. We use the optical observations to model the galaxy substructure and estimate line of sight motion. In conjunction with the radio and X-ray data, these substructure models helped elucidate the most likely merger scenario for each system and further constrain the dynamical properties of each system. We demonstrate the power of this technique through detailed analyses of two individual merging clusters. Each are largely bimodal mergers occurring in the plane of the sky. We build on the dynamical analyses of Dawson (2013b) and Ng et al. (2015) in order to constrain the merger speeds, timescales, and geometry for these two systems, which are among a gold sample earmarked for further follow up. Findings: MACS J1149.5+2223 has a previously unidentified southern subcluster involved in a major merger with the well-studied northern subcluster. We confirm the system to be among the most massive clusters known, and we study the dynamics of the merger. MACS J1149.5+2223 appears to be a more evolved system than the Bullet Cluster observed near apocenter. ZwCl 0008.8+5215 is a less massive but a bimodal system with two radio relics and a cool-core "bullet" analogous to the namesake of the Bullet Cluster. These two systems occupy different regions of merger phase space with the pericentric relative velocities of ˜2800 km s-1 and ˜1800 km s-1 for MACS J1149.5+2223 and ZwCl 0008.8+5215, respectively. The time since pericenter for the observed states are ˜1.2 Gyr and ˜0.8 Gyr, respectivel. In the ensemble analysis, we confirm that radio relic selection is an efficient trigger for the identification of major mergers. In particular, 28 of the 29 systems exhibit galaxy substructure aligned with the radio relics and the disturbed intra-cluster medium. Radio relics are typically aligned within 20° of the axis connecting the two galaxy subclusters. Furthermore, when radio relics are aligned with substructure, the line of sight velocity difference between the two subclusters is small compared with the infall velocity. This strongly implies radio relic selection is an efficient selector of systems merging in the plane of the sky. While many of the systems are complex with several simultaneous merging subclusters, these systems generally only contain one radio relic. Systems with double radio relics uniformly suggest major mergers with two dominant substructures well aligned between the radio relics. Conclusions: Radio relics are efficient triggers for identifying major mergers occurring within the plane of the sky. This is ideal for observing offsets between galaxies and dark matter distributions as well as cluster shocks. Double radio relic systems, in particular, have the simplest geometries, which allow for accurate dynamical models and inferred astrophysics. Comparing and contrasting the dynamical models of MACS J1149.5+2223 and ZwCl 0008.8+5215 with similar studies in the literature (Dawson, 2013b; Ng et al., 2015; van Weeren et al., 2017), a wide range of dynamical phase space (˜ 1500 - 3000 km -1 at pericenter and ˜ 500 - 1500 Myr after pericenter) may be sampled with radio relic mergers. With sufficient samples of bimodal systems, velocity dependence of underlying astrophysics may be uncovered. (Abstract shortened by ProQuest.).

RELICS: Reionization Lensing Cluster Survey - Discovering Brightly Lensed Distant Galaxies for JWST

NASA Astrophysics Data System (ADS)

Coe, Dan; Bradley, Larry; Salmon, Brett; Avila, Roberto J.; Ogaz, Sara; Bradac, Marusa; Huang, Kuang-Han; Strait, Victoria; Hoag, Austin; Sharon, Keren q.; Cerny, Catherine; Paterno-Mahler, Rachel; Johnson, Traci Lin; Mahler, Guillaume; Zitrin, Adi; Sendra Server, Irene; Acebron, Ana; Cibirka, Nathália; Rodney, Steven; Strolger, Louis; Riess, Adam; Dawson, William; Jones, Christine; Andrade-Santos, Felipe; Lovisari, Lorenzo; Czakon, Nicole; Umetsu, Keiichi; Trenti, Michele; Vulcani, Benedetta; Carrasco, Daniela; Livermore, Rachael; Stark, Daniel P.; Mainali, Ramesh; Frye, Brenda; Oesch, Pascal; Lam, Daniel; Toft, Sune; Ryan, Russell; Peterson, Avery; Past, Matthew; Kikuchihara, Shotaro; Ouchi, Masami; Oguri, Masamune

2018-01-01

The Reionization Lensing Cluster Survey (RELICS) Hubble Treasury Program has completed observations of 41 massive galaxy clusters with 188 orbits of HST ACS and WFC3/IR imaging and 390 hours of Spitzer IRAC imaging. This poster presents an overview of the program and data releases. Reduced images, catalogs, and lens models for all clusters are now available on MAST. RELICS is studying the clusters, supernovae, and lensed high-redshift galaxies. A companion poster presents our high-redshift results: over 300 lensed z ~ 6 - 10 candidates, including some of the brightest known at these redshifts (Salmon et al. 2018). These will be excellent targets for detailed follow-up study in JWST Cycle 1 GO proposals.

Phenomenology of left-right symmetric dark matter

DOE Office of Scientific and Technical Information (OSTI.GOV)

Garcia-Cely, Camilo; Heeck, Julian, E-mail: Camilo.Alfredo.Garcia.Cely@ulb.ac.be, E-mail: Julian.Heeck@ulb.ac.be

We present a detailed study of dark matter phenomenology in low-scale left-right symmetric models. Stability of new fermion or scalar multiplets is ensured by an accidental matter parity that survives the spontaneous symmetry breaking of the gauge group by scalar triplets. The relic abundance of these particles is set by gauge interactions and gives rise to dark matter candidates with masses above the electroweak scale. Dark matter annihilations are thus modified by the Sommerfeld effect, not only in the early Universe, but also today, for instance, in the Center of the Galaxy. Majorana candidates—triplet, quintuplet, bi-doublet, and bi-triplet—bring only onemore » new parameter to the model, their mass, and are hence highly testable at colliders and through astrophysical observations. Scalar candidates—doublet and 7-plet, the latter being only stable at the renormalizable level—have additional scalar-scalar interactions that give rise to rich phenomenology. The particles under discussion share many features with the well-known candidates wino, Higgsino, inert doublet scalar, sneutrino, and Minimal Dark Matter. In particular, they all predict a large gamma-ray flux from dark matter annihilations, which can be searched for with Cherenkov telescopes. We furthermore discuss models with unequal left-right gauge couplings, g{sub R} ≠ g{sub L}, taking the recent experimental hints for a charged gauge boson with 2 TeV mass as a benchmark point. In this case, the dark matter mass is determined by the observed relic density.« less

Asymmetric thermal-relic dark matter: Sommerfeld-enhanced freeze-out, annihilation signals and unitarity bounds

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baldes, Iason; Petraki, Kalliopi, E-mail: iason.baldes@desy.de, E-mail: kpetraki@lpthe.jussieu.fr

Dark matter that possesses a particle-antiparticle asymmetry and has thermalised in the early universe, requires a larger annihilation cross-section compared to symmetric dark matter, in order to deplete the dark antiparticles and account for the observed dark matter density. The annihilation cross-section determines the residual symmetric component of dark matter, which may give rise to annihilation signals during CMB and inside haloes today. We consider dark matter with long-range interactions, in particular dark matter coupled to a light vector or scalar force mediator. We compute the couplings required to attain a final antiparticle-to-particle ratio after the thermal freeze-out of themore » annihilation processes in the early universe, and then estimate the late-time annihilation signals. We show that, due to the Sommerfeld enhancement, highly asymmetric dark matter with long-range interactions can have a significant annihilation rate, potentially larger than symmetric dark matter of the same mass with contact interactions. We discuss caveats in this estimation, relating to the formation of stable bound states. Finally, we consider the non-relativistic partial-wave unitarity bound on the inelastic cross-section, we discuss why it can be realised only by long-range interactions, and showcase the importance of higher partial waves in this regime of large inelasticity. We derive upper bounds on the mass of symmetric and asymmetric thermal-relic dark matter for s -wave and p -wave annihilation, and exhibit how these bounds strengthen as the dark asymmetry increases.« less

Superpixel segmentation and pigment identification of colored relics based on visible spectral image.

PubMed

Li, Junfeng; Wan, Xiaoxia

2018-01-15

To enrich the contents of digital archive and to guide the copy and restoration of colored relics, non-invasive methods for extraction of painting boundary and identification of pigment composition are proposed in this study based on the visible spectral images of colored relics. Superpixel concept is applied for the first time to the field of oversegmentation of visible spectral images and implemented on the visible spectral images of colored relics to extract their painting boundary. Since different pigments are characterized by their own spectrum and the same kind of pigment has the similar geometric profile in spectrum, an automatic identification method is established by comparing the proximity between the geometric profiles of the unknown spectrum from each superpixel and the pre-known spectrum from a deliberately prepared database. The methods are validated using the visible spectral images of the ancient wall paintings in Mogao Grottoes. By the way, the visible spectral images are captured by a multispectral imaging system consisting of two broadband filters and a RGB camera with high spatial resolution. Copyright © 2017 Elsevier B.V. All rights reserved.

Curved Radio Spectra of Weak Cluster Shocks

NASA Astrophysics Data System (ADS)

Kang, Hyesung; Ryu, Dongsu

2015-08-01

In order to understand certain observed features of arc-like giant radio relics such as the rareness, uniform surface brightness, and curved integrated spectra, we explore a diffusive shock acceleration (DSA) model for radio relics in which a spherical shock impinges on a magnetized cloud containing fossil relativistic electrons. Toward this end, we perform DSA simulations of spherical shocks with the parameters relevant for the Sausage radio relic in cluster CIZA J2242.8+5301, and calculate the ensuing radio synchrotron emission from re-accelerated electrons. Three types of fossil electron populations are considered: a delta-function like population with the shock injection momentum, a power-law distribution, and a power law with an exponential cutoff. The surface brightness profile of the radio-emitting postshock region and the volume-integrated radio spectrum are calculated and compared with observations. We find that the observed width of the Sausage relic can be explained reasonably well by shocks with speed {u}{{s}}˜ 3× {10}3 {km} {{{s}}}-1 and sonic Mach number {M}{{s}}˜ 3. These shocks produce curved radio spectra that steepen gradually over (0.1-10){ν }{br} with a break frequency {ν }{br}˜ 1 GHz if the duration of electron acceleration is ˜60-80 Myr. However, the abrupt increase in the spectral index above ˜1.5 GHz observed in the Sausage relic seems to indicate that additional physical processes, other than radiative losses, operate for electrons with {γ }{{e}}≳ {10}4.

A powerful double radio relic system discovered in PSZ1 G108.18-11.53: evidence for a shock with non-uniform Mach number?

DOE PAGES

de Gasperin, F.; Intema, H. T.; van Weeren, R. J.; ...

2015-09-09

Diffuse radio emission in the form of radio haloes and relics has been found in a number of merging galaxy clusters. These structures indicate that shock and turbulence associated with the merger accelerate electrons to relativistic energies. We report the discovery of a radio relic + radio halo system in PSZ1 G108.18-11.53 (z = 0.335). This cluster hosts the second most powerful double radio relic system ever discovered. We observed PSZ1 G108.18-11.53 with the Giant Meterwave Radio Telescope and the Westerbork Synthesis Radio Telescope. We obtained radio maps at 147, 323, 607 and 1380 MHz. We also observed the cluster with the Keck telescope, obtaining the spectroscopic redshift for 42 cluster members. From the injection index, we obtained the Mach number of the shocks generating the two radio relics. For the southern shock, we foundmore » $M$ = 2.33 $$+0.19\\atop{-0.26}$$ while the northern shock Mach number goes from $M$2.20 $$+0.07\\atop{-0.14}$$ in the north part down to $M$ = 200 $$+0.03\\atop{-0.08}$$ in the southern region. Finally, if the relation between the injection index and the Mach number predicted by diffusive shock acceleration theory holds, this is the first observational evidence for a gradient in the Mach number along a galaxy cluster merger shock.« less

Threshold Effects Beyond the Standard Model

NASA Astrophysics Data System (ADS)

Taylor, T. R.

In this contribution to the Festschrift celebrating Gabriele Veneziano on his 65th birthday, I discuss the threshold effects of extra dimensions and their applications to physics beyond the standard model, focusing on superstring theory.

DIS off glueballs from string theory: the role of the chiral anomaly and the Chern-Simons term

NASA Astrophysics Data System (ADS)

Kovensky, Nicolas; Michalski, Gustavo; Schvellinger, Martin

2018-04-01

We calculate the structure function F 3( x, q 2) of the hadronic tensor of deep inelastic scattering (DIS) of charged leptons from glueballs of N=4 SYM theory at strong coupling and at small values of the Bjorken parameter in the gauge/string theory duality framework. This is done in terms of type IIB superstring theory scattering amplitudes. From the AdS5 perspective, the relevant part of the scattering amplitude comes from the five-dimensional non-Abelian Chern-Simons terms in the SU(4) gauged supergravity obtained from dimensional reduction on S 5. From type IIB superstring theory we derive an effective Lagrangian describing the four-point interaction in the local approximation. The exponentially small regime of the Bjorken parameter is investigated using Pomeron techniques.

Relict grains in chondrules: Evidence for chondrule recycling

NASA Technical Reports Server (NTRS)

Jones, R. H.

1994-01-01

The presence of relict grains in chondrules, which offers some insight into the degree to which chondrule material was recycled in the chondrule-forming region, is discussed in this report. Relics are grains that clearly did not crystallize in situ in the host chondrule. They represent coarse-grained precursor material that did not melt during chondrule formation, and provide the only tangible record of chondrule precursor grains. Relics are commonly identified by a large difference in size, textural differences, and/or significant compositional differences compared with normal grains in the host chondrule. Two important types of relics are: (1) 'dusty,' metal-bearing grains of olivine and pyroxene; and (2) forsterite (Mg-rich olivine) grains present in FeO-rich chondrules.

A 750 GeV portal: LHC phenomenology and dark matter candidates

DOE PAGES

D’Eramo, Francesco; de Vries, Jordy; Panci, Paolo

2016-05-16

We study the effective field theory obtained by extending the Standard Model field content with two singlets: a 750 GeV (pseudo-)scalar and a stable fermion. Accounting for collider productions initiated by both gluon and photon fusion, we investigate where the theory is consistent with both the LHC diphoton excess and bounds from Run 1. We analyze dark matter phenomenology in such regions, including relic density constraints as well as collider, direct, and indirect bounds. Scalar portal dark matter models are very close to limits from direct detection and mono-jet searches if gluon fusion dominates, and not constrained at all otherwise.more » In conclusion, pseudo-scalar models are challenged by photon line limits and mono-jet searches in most of the parameter space.« less

A 750 GeV portal: LHC phenomenology and dark matter candidates

DOE Office of Scientific and Technical Information (OSTI.GOV)

D’Eramo, Francesco; de Vries, Jordy; Panci, Paolo

We study the effective field theory obtained by extending the Standard Model field content with two singlets: a 750 GeV (pseudo-)scalar and a stable fermion. Accounting for collider productions initiated by both gluon and photon fusion, we investigate where the theory is consistent with both the LHC diphoton excess and bounds from Run 1. We analyze dark matter phenomenology in such regions, including relic density constraints as well as collider, direct, and indirect bounds. Scalar portal dark matter models are very close to limits from direct detection and mono-jet searches if gluon fusion dominates, and not constrained at all otherwise.more » In conclusion, pseudo-scalar models are challenged by photon line limits and mono-jet searches in most of the parameter space.« less

Warped unification, proton stability, and dark matter.

PubMed

Agashe, Kaustubh; Servant, Géraldine

2004-12-03

We show that solving the problem of baryon-number violation in nonsupersymmetric grand unified theories (GUT's) in warped higher-dimensional spacetime can lead to a stable Kaluza-Klein particle. This exotic particle has gauge quantum numbers of a right-handed neutrino, but carries fractional baryon number and is related to the top quark within the higher-dimensional GUT. A combination of baryon number and SU(3) color ensures its stability. Its relic density can easily be of the right value for masses in the 10 GeV-few TeV range. An exciting aspect of these models is that the entire parameter space will be tested at near future dark matter direct detection experiments. Other exotic GUT partners of the top quark are also light and can be produced at high energy colliders with distinctive signatures.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Diaz-Cruz, J. Lorenzo

We propose a dark matter candidate within the class of models where electroweak symmetry breaking is triggered by a light composite Higgs boson. In these dual anti-de Sitter/conformal field theory models, the Higgs boson emerges as a holographic pseudo-Goldstone boson, while dark matter can be identified with a stable composite fermion X{sup 0}. The effective Lagrangian description of the Higgs and X{sup 0}-multiplets, including higher-dimensional operators, can be tested at future colliders (LHC, ILC) and through astrophysical signals (ultrahigh-energy cosmic rays). The expected mass of X{sup 0}, m{sub X{sup 0}} < or approx. 4{pi}f{approx_equal}O (TeV), satisfies the bounds extracted frommore » the cosmological relic density, while the experimental searches for dark matter further constrains the possible models.« less

Effective theories and thresholds in particle physics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gaillard, M.K.

1991-06-07

The role of effective theories in probing a more fundamental underlying theory and in indicating new physics thresholds is discussed, with examples from the standard model and more speculative applications to superstring theory. 38 refs.

Dusty Relic to Shining Treasure: Embedded in a Multicultural Environment

ERIC Educational Resources Information Center

Avery, Beth Fuseler; Batman, Cindy

2014-01-01

Far from being dusty old relics who are guardians of the book, embedded librarians need to be proactively leading students through the digital maze of the virtual library. Working with students more than 7,000 miles away changed perceptions of how to teach and learn, and how people interact online. We will share how as embedded librarians we…

The relic Criollo cacao in Belize- genetic diversity and relationship with Trinitario and other cacao clones held in the International Cocoa Genebank, Trinidad

USDA-ARS?s Scientific Manuscript database

Cacao (Theobroma cacao L.) is native to the South American rainforest but it was domesticated in Mesoamerica. The relic Criollo cocoa in Belize has been well known in the premium chocolate market for its high-quality. Knowledge of genetic diversity in this variety is essential for efficient conserva...

Ecophysiology of seedling establishment in contrasting spruce-fir forests of southern Appalachian and Rocky Mountain ecotones, USA

Treesearch

William K. Smith; Keith N.C. Reinhardt; Daniel M. Johnson

2010-01-01

Fraser fir (Abies fraseri [Pursh] Poiret) and red spruce (Picea rubens Sarg.) occur as codominant trees in six relic, mountain-top populations that make up the high-elevation forests of the Southern Appalachian Mountains (SA). These two relic species of the former boreal forest have experienced a significant decline over the past...

RELIC: a novel dye-bias correction method for Illumina Methylation BeadChip.

PubMed

Xu, Zongli; Langie, Sabine A S; De Boever, Patrick; Taylor, Jack A; Niu, Liang

2017-01-03

The Illumina Infinium HumanMethylation450 BeadChip and its successor, Infinium MethylationEPIC BeadChip, have been extensively utilized in epigenome-wide association studies. Both arrays use two fluorescent dyes (Cy3-green/Cy5-red) to measure methylation level at CpG sites. However, performance difference between dyes can result in biased estimates of methylation levels. Here we describe a novel method, called REgression on Logarithm of Internal Control probes (RELIC) to correct for dye bias on whole array by utilizing the intensity values of paired internal control probes that monitor the two color channels. We evaluate the method in several datasets against other widely used dye-bias correction methods. Results on data quality improvement showed that RELIC correction statistically significantly outperforms alternative dye-bias correction methods. We incorporated the method into the R package ENmix, which is freely available from the Bioconductor website ( https://www.bioconductor.org/packages/release/bioc/html/ENmix.html ). RELIC is an efficient and robust method to correct for dye-bias in Illumina Methylation BeadChip data. It outperforms other alternative methods and conveniently implemented in R package ENmix to facilitate DNA methylation studies.

MadDM: Computation of dark matter relic abundance

NASA Astrophysics Data System (ADS)

Backović, Mihailo; Kong, Kyoungchul; McCaskey, Mathew

2017-12-01

MadDM computes dark matter relic abundance and dark matter nucleus scattering rates in a generic model. The code is based on the existing MadGraph 5 architecture and as such is easily integrable into any MadGraph collider study. A simple Python interface offers a level of user-friendliness characteristic of MadGraph 5 without sacrificing functionality. MadDM is able to calculate the dark matter relic abundance in models which include a multi-component dark sector, resonance annihilation channels and co-annihilations. The direct detection module of MadDM calculates spin independent / spin dependent dark matter-nucleon cross sections and differential recoil rates as a function of recoil energy, angle and time. The code provides a simplified simulation of detector effects for a wide range of target materials and volumes.

The radio relics and halo of El Gordo, a massive z = 0.870 cluster merger

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lindner, Robert R.; Baker, Andrew J.; Hughes, John P.

We present 610 MHz and 2.1 GHz imaging of the massive Sunyaev-Zel'dovich Effect selected z = 0.870 cluster merger ACT-CL J0102–4915 ({sup E}l Gordo{sup )}, obtained with the Giant Metrewave Radio Telescope and the Australia Telescope Compact Array (ATCA), respectively. We detect two complexes of radio relics separated by 3.'4 (1.6 Mpc) along the system's northwest-to-southeast collision axis that have high integrated polarization fractions (33%) and steep spectral indices (α between 1 and 2; S {sub ν}∝ν{sup –α}), consistent with creation via Fermi acceleration by shocks in the intracluster medium triggered by the cluster collision. From the spectral index ofmore » the relics, we compute a Mach number M=2.5{sub −0.3}{sup +0.7} and shock speed of 2500{sub −300}{sup +400} km s{sup −1}. With our wide-bandwidth, full-polarization ATCA data, we compute the Faraday depth φ across the northwest relic and find a range of values spanning Δφ = 30 rad m{sup –2}, with a mean value of (φ) = 11 rad m{sup –2} and standard deviation σ{sub φ} = 6 rad m{sup –2}. With the integrated line-of-sight gas density derived from new Chandra X-ray observations, our Faraday depth measurement implies B {sub ∥} ∼ 0.01 μG in the cluster outskirts. The extremely narrow shock widths in the relics (d {sub shock} ≤ 23 kpc), caused by the short synchrotron cooling timescale of relativistic electrons at z = 0.870, prevent us from placing a meaningful constraint on the magnetic field strength B using cooling time arguments. In addition to the relics, we detect a large (r {sub H} ≅ 1.1 Mpc radius), powerful (log (L {sub 1.4}/W Hz{sup –1}) = 25.66 ± 0.12) radio halo with a shape similar to El Gordo's 'bullet'-like X-ray morphology. The spatially resolved spectral-index map of the halo shows the synchrotron spectrum is flattest near the relics, along the system's collision axis, and in regions of high T {sub gas}, all locations associated with recent energy injection. The spatial and spectral correlation between the halo emission and cluster X-ray properties supports primary-electron processes like turbulent reacceleration as the halo production mechanism. The halo's integrated 610 MHz to 2.1 GHz spectral index is a relatively flat α = 1.2 ± 0.1, consistent with the cluster's high T {sub gas} in view of previously established global scaling relations. El Gordo is the highest-redshift cluster known to host a radio halo and/or radio relics, and provides new constraints on the non-thermal physics in clusters at z > 0.6.« less

Noncommutative Field Theories and (super)string Field Theories

NASA Astrophysics Data System (ADS)

Aref'eva, I. Ya.; Belov, D. M.; Giryavets, A. A.; Koshelev, A. S.; Medvedev, P. B.

2002-11-01

In this lecture notes we explain and discuss some ideas concerning noncommutative geometry in general, as well as noncommutative field theories and string field theories. We consider noncommutative quantum field theories emphasizing an issue of their renormalizability and the UV/IR mixing. Sen's conjectures on open string tachyon condensation and their application to the D-brane physics have led to wide investigations of the covariant string field theory proposed by Witten about 15 years ago. We review main ingredients of cubic (super)string field theories using various formulations: functional, operator, conformal and the half string formalisms. The main technical tools that are used to study conjectured D-brane decay into closed string vacuum through the tachyon condensation are presented. We describe also methods which are used to study the cubic open string field theory around the tachyon vacuum: construction of the sliver state, "comma" and matrix representations of vertices.

On pp wave limit for η deformed superstrings

NASA Astrophysics Data System (ADS)

Roychowdhury, Dibakar

2018-05-01

In this paper, based on the notion of plane wave string/gauge theory duality, we explore the pp wave limit associated with the bosonic sector of η deformed superstrings propagating in ( AdS 5 × S 5) η . Our analysis reveals that in the presence of NS-NS and RR fluxes, the pp wave limit associated to full ABF background satisfies type IIB equations in its standard form. However, the beta functions as well as the string Hamiltonian start receiving non trivial curvature corrections as one starts probing beyond pp wave limit which thereby takes solutions away from the standard type IIB form. Furthermore, using uniform gauge, we also explore the BMN dynamics associated with short strings and compute the corresponding Hamiltonian density. Finally, we explore the Penrose limit associated with the HT background and compute the corresponding stringy spectrum for the bosonic sector.

Democratic superstring field theory: gauge fixing

NASA Astrophysics Data System (ADS)

Kroyter, Michael

2011-03-01

We show that a partial gauge fixing of the NS sector of the democratic-picture superstring field theory leads to the non-polynomial theory. Moreover, by partially gauge fixing the Ramond sector we obtain a non-polynomial fully RNS theory at pictures 0 and 1/2 . Within the democratic theory and in the partially gauge fixed theory the equations of motion of both sectors are derived from an action. We also discuss a representation of the non-polynomial theory analogous to a manifestly two-dimensional representation of WZW theory and the action of bosonic pure-gauge solutions. We further demonstrate that one can consistently gauge fix the NS sector of the democratic theory at picture number -1. The resulting theory is new. It is a {mathbb{Z}_2} dual of the modified cubic theory. We construct analytical solutions of this theory and show that they possess the desired properties.

Atmospheric-Pressure-Spray, Chemical- Vapor-Deposited Thin-Film Materials Being Developed for High Power-to- Weight-Ratio Space Photovoltaic Applications

NASA Technical Reports Server (NTRS)

Hepp, Aloysius F.; Harris, Jerry D.; Raffaelle, Ryne P.; Banger, Kulbinder K.; Smith, Mark A.; Cowen, Jonathan E.

2001-01-01

The key to achieving high specific power (watts per kilogram) space photovoltaic arrays is the development of high-efficiency thin-film solar cells that are fabricated on lightweight, space-qualified substrates such as Kapton (DuPont) or another polymer film. Cell efficiencies of 20 percent air mass zero (AM0) are required. One of the major obstacles to developing lightweight, flexible, thin-film solar cells is the unavailability of lightweight substrate or superstrate materials that are compatible with current deposition techniques. There are two solutions for working around this problem: (1) develop new substrate or superstrate materials that are compatible with current deposition techniques, or (2) develop new deposition techniques that are compatible with existing materials. The NASA Glenn Research Center has been focusing on the latter approach and has been developing a deposition technique for depositing thin-film absorbers at temperatures below 400 C.

A superstring field theory for supergravity

NASA Astrophysics Data System (ADS)

Reid-Edwards, R. A.; Riccombeni, D. A.

2017-09-01

A covariant closed superstring field theory, equivalent to classical tendimensional Type II supergravity, is presented. The defining conformal field theory is the ambitwistor string worldsheet theory of Mason and Skinner. This theory is known to reproduce the scattering amplitudes of Cachazo, He and Yuan in which the scattering equations play an important role and the string field theory naturally incorporates these results. We investigate the operator formalism description of the ambitwsitor string and propose an action for the string field theory of the bosonic and supersymmetric theories. The correct linearised gauge symmetries and spacetime actions are explicitly reproduced and evidence is given that the action is correct to all orders. The focus is on the NeveuSchwarz sector and the explicit description of tree level perturbation theory about flat spacetime. Application of the string field theory to general supergravity backgrounds and the inclusion of the Ramond sector are briefly discussed.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pern, F. J.; Glick, S. H.

We have conducted a series of accelerated exposure test (AET) studies for various crystalline-Si (c-Si) and amorphous-Si (a-Si) cell samples that were encapsulated with different superstrates, pottants, and substrates. Nonuniform browning patterns of ethylene vinyl acetate (EVA) pottants were observed for glass/EVA/glass-encapsulated c-Si cell samples under solar simulator exposures at elevated temperatures. The polymer/polymer-configured laminates with Tedlar or Tefzel did not discolor because of photobleaching reactions, but yellowed with polyester or nylon top films. Delamination was observed for the polyester/EVA layers on a-Si minimodules and for a polyolefin-based thermoplastic pottant at high temperatures. For all tested c-Si cell samples, irregularmore » changes in the current-voltage parameters were observed that could not be accounted for simply by the transmittance changes of the superstrate/pottant layers. Silicone-type adhesives used under UV-transmitting polymer top films were observed to cause greater cell current/efficiency loss than EVA or polyethylene pottants.« less

Compactification and inflation in the superstring theory from the condensation of gravitino pairs

NASA Astrophysics Data System (ADS)

Pollock, M. D.

1987-12-01

We discuss the possibility that inflation can occur in the E8×E8' heterotic superstring theory, if there is a pair condensation of the gravitino field ψA and also of the Majorana-Weyl spinor λ, as suggested by the Helayël-Neto and Smith. In the absence of a condensation of the anti-symmetric tensor field HMNP, then the associated potential V(θ,φ) is bounded from below and independent of the dilaton field φ. It can be made to vanish at the minimum, where the compactification scale θ is fixed. Alternatively, a small cosmological constant may remain (ultimately to be cancelled by radiative corrections at the lower energy scale of the gaugino condensation), which could in principle lead to inflation. Present address: Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Bombay 400 005, India.

Geochemistry and petrogenesis of serpentinite from the Ingalls ophiolite complex, central Cascades, Washington

NASA Astrophysics Data System (ADS)

MacDonald, J. H., Jr.; Milliken, S. H.; Zalud, K. M.

2017-12-01

The Jurassic Ingalls ophiolite complex is located in the central Cascades, Washington State. This ophiolite predominantly consists of three variably serpentinized mantle units. Serpentinite occurs as massive replacing peridotite, or as highly sheared fault zones cutting other rocks. Mylonitic serpentinite forms a large-scale mélange in the middle of the ophiolite, and is interpreted as a fracture zone. Whole-rock and mineral geochemistry of the massive serpentinite was done to understand the metasomatic process and identify the possible protoliths of these rocks. Whole-rock major and trace elements of the massive serpentinite are similar to modern peridotites. The majority of samples analyzed are strongly serpentinized, while a few were moderately to weakly altered. Ca, Mg, and Al suggest these rocks formed from serpentinized harzburgite and dunite with minor lherzolite. All samples have positive Eu/Eu*. Serpentinites plot in fields defined by modern abyssal and forearc peridotites. Trace elements suggests the protoliths underwent variable amounts of mantel depletion (5-20%). Serpentine and relic igneous minerals were analyzed by EPMA at the Florida Center for Analytical Electron Microscopy. The serpentine dose not chemically display brucite mixing, has minor substitution of Fe, Ni, and Cr for Mg, and minor Al substitution for Si. Bastites have higher Ni than replaced olivine. Mineral chemistry, high LOI, and X-ray diffraction suggest lizardite is the primary serpentine polymorph, with minor chrysotile also occurring. Relic Al-chromite and Cr-spinel commonly have Cr-magnetite rims. These relic cores have little SiO2 and Fe3+, suggesting the spinels are well preserved. Most spinels plot in overlap fields defined by abyssal and arc peridotite, while two samples plot entirely in arc fields. Relic olivine have Fo90 to Fo92 and plot along the mantle array. Relic pyroxene are primarily enstatite, with lesser high-Ca varieties. Relic minerals plot near fields defined by harzburgite, dunite, and lherzolite from unaltered Ingalls peridotite. The massive serpentinite likely formed by low T (< 300°C), and possibly low pressure, hydrothermal alteration of harzburgite, dunite and lherzolite. The protoliths were variably depleted mantle residues from a possible supra-subduction zone setting.

The dark side of electroweak naturalness beyond the MSSM

NASA Astrophysics Data System (ADS)

Bélanger, Geneviève; Delaunay, Cédric; Goudelis, Andreas

2015-04-01

Weak scale supersymmetry (SUSY) remains a prime explanation for the radiative stability of the Higgs field. A natural account of the Higgs boson mass, however, strongly favors extensions of the Minimal Supersymmetric Standard Model (MSSM). A plausible option is to introduce a new supersymmetric sector coupled to the MSSM Higgs fields, whose associated states resolve the little hierarchy problem between the third generation soft parameters and the weak scale. SUSY also accomodates a weakly interacting cold dark matter (DM) candidate in the form of a stable neutralino. In minimal realizations, the thus-far null results of direct DM searches, along with the DM relic abundance constraint, introduce a level of fine-tuning as severe as the one due to the SUSY little hierarchy problem. We analyse the generic implications of new SUSY sectors parametrically heavier than the minimal SUSY spectrum, devised to increase the Higgs boson mass, on this "little neutralino DM problem". We focus on the SUSY operator of smallest scaling dimension in an effective field theory description, which modifies the Higgs and DM sectors in a correlated manner. Within this framework, we show that recent null results from the LUX experiment imply a tree-level fine-tuning for gaugino DM which is parametrically at least a few times larger than that of the MSSM. Higgsino DM whose relic abundance is generated through a thermal freeze-out mechanism remains also severely fine-tuned, unless the DM lies below the weak boson pair-production threshold. As in the MSSM, well-tempered gaugino-Higgsino DM is strongly disfavored by present direct detection results.

On the dynamics of superstring compactification

NASA Astrophysics Data System (ADS)

Pollock, M. D.

2018-05-01

Compactification of the ten-dimensional heterotic superstring theory to four dimensions gives rise to two moduli potentials VA, VB, the positive semi-definiteness of which places constraints on the Euler characteristic \\bar{χ} of the internal space \\bar{g}_{μν}(y^{ξ}) and the adiabatic index γ of the effective matter source of energy-density ρ and pressure p = (γ -1)ρ that generates the physical four-space g_{ij}(xk), namely \\bar{χ} < 0, 4/3 ≤ γ ≤ 2, or \\bar{χ} > 0, 1 ≤ γ ≤ 4/3. Here, we show how fermion-bilinear condensation in the internal space, first put forward by Helayël-Neto and Smith, determines the field \\tilde{β} ≡ A_r B_r3, thus reducing the moduli space to a single canonical field \\tilde{σ}=2σB with a potential ˜ , which is positive semi-definite under the same conditions that ensure positive semi-definiteness of VA, VB, and has a minimum at a value of \\tilde{β} that is approximately constant far from the Planck era at t ≫ t_P. The fields σA, σB, which are canonically normalized in the zero-slope limit, are modified by contributions originating from the higher-derivative gravitational terms α^' \\hatR_E2 and α^' 3} \\hatR4, but the associated kinetic energy remains positive for times t ≳ t_P/2, guaranteeing classical stability of the solution, since the generalized indeterminacy principle implies a minimum physically measurable time t0 ≈ 50 t_P for the superstring theory.

Big Bangs in Galaxy Clusters: Using X-ray Temperature Maps to Trace Merger Histories in Clusters with Radio Halos/Relics

NASA Astrophysics Data System (ADS)

Burns, Jack O.; Datta, Abhirup; Hallman, Eric J.

2016-06-01

Galaxy clusters are assembled through large and small mergers which are the most energetic events ("bangs") since the Big Bang. Cluster mergers "stir" the intracluster medium (ICM) creating shocks and turbulence which are illuminated by ~Mpc-sized radio features called relics and halos. These shocks heat the ICM and are detected in x-rays via thermal emission. Disturbed morphologies in x-ray surface brightness and temperatures are direct evidence for cluster mergers. In the radio, relics (in the outskirts of the clusters) and halos (located near the cluster core) are also clear signposts of recent mergers. Our recent ENZO cosmological simulations suggest that around a merger event, radio emission peaks very sharply (and briefly) while the x-ray emission rises and decays slowly. Hence, a sample of galaxy clusters that shows both luminous x-ray emission and radio relics/halos are good candidates for very recent mergers. We are in the early stages of analyzing a unique sample of 48 galaxy clusters with (i) known radio relics and/or halos and (ii) significant archival x-ray observations (>50 ksec) from Chandra and/or XMM. We have developed a new x-ray data analysis pipeline, implemented on parallel processor supercomputers, to create x-ray surface brightness, high fidelity temperature, and pressure maps of these clusters in order to study merging activity. The temperature maps are made using three different map-making techniques: Weighted Voronoi Tessellation, Adaptive Circular Binning, and Contour Binning. In this talk, we will show preliminary results for several clusters, including Abell 2744 and the Bullet cluster. This work is supported by NASA ADAP grant NNX15AE17G.

A lunar-based detector to search for relic supernovae antineutrinos

NASA Astrophysics Data System (ADS)

Mann, A. K.; Zhang, W.

1990-03-01

Observations of the relic supernovae antineutrino flux are argued to be possible near the lowest theoretical estimates of the flux by means of a suitable detector located on the moon. The status of the search for the relic flux is discussed with illustrations of the data obtained by terrestrial searches. The detector concept is described, and the advantages are found to include the fact that a lunar detector would not detect the electron-type antineutrinos related to nuclear reactors. Similarly, the lunar detector would not be affected by the flux of neutrinos and antineutrinos generated by the cosmic-ray proton flux in the atmosphere. The relative abundance of radioisotopes on the moon is similar to that found on earth, so that the background lunar radioactivity would have little effect on the detection of antineutrinos.

Demonstration of three gorges archaeological relics based on 3D-visualization technology

NASA Astrophysics Data System (ADS)

Xu, Wenli

2015-12-01

This paper mainly focuses on the digital demonstration of three gorges archeological relics to exhibit the achievements of the protective measures. A novel and effective method based on 3D-visualization technology, which includes large-scaled landscape reconstruction, virtual studio, and virtual panoramic roaming, etc, is proposed to create a digitized interactive demonstration system. The method contains three stages: pre-processing, 3D modeling and integration. Firstly, abundant archaeological information is classified according to its history and geographical information. Secondly, build up a 3D-model library with the technology of digital images processing and 3D modeling. Thirdly, use virtual reality technology to display the archaeological scenes and cultural relics vividly and realistically. The present work promotes the application of virtual reality to digital projects and enriches the content of digital archaeology.

Noble gases in the Murchison meteorite - Possible relics of s-process nucleosynthesis

NASA Technical Reports Server (NTRS)

Srinivasan, B.; Anders, E.

1978-01-01

The Murchison carbonaceous chondrite contains a new type of xenon component, enriched by up to 50 percent in five of the nine stable xenon isotopes, mass numbers 128 to 132. This component is released at 1200 to 1600 C from a severely etched mineral fraction. Krypton shows a similar but smaller enrichment in the isotopes 80 and 82. Neon and helium released in the same interval also are quite anomalous, being highly enriched in the isotopes 22 and 3. These patterns are strongly suggestive of three nuclear processes believed to take place in red giants: the s process (neutron capture on a slow time scale), helium burning, and hydrogen shell burning. If this interpretation is correct, then primitive meteorites contain yet another kind of alien, presolar material: dust grains ejected from red giants.

Study of electroweak vacuum stability from extended Higgs portal of dark matter and neutrinos

NASA Astrophysics Data System (ADS)

Ghosh, Purusottam; Saha, Abhijit Kumar; Sil, Arunansu

2018-04-01

We investigate the electroweak vacuum stability in an extended version of the Standard Model that incorporates two additional singlet scalar fields and three right-handed neutrinos. One of these extra scalars plays the role of dark matter, while the other scalar not only helps make the electroweak vacuum stable but also opens up the low-mass window of the scalar singlet dark matter (<500 GeV ). We consider the effect of large neutrino Yukawa coupling on the running of Higgs quartic coupling. We have analyzed the constraints on the model and identified the range of parameter space that is consistent with the neutrino mass, appropriate relic density, and direct search limits from the latest XENON 1T preliminary result as well as realized the stability of the electroweak vacuum up to the Planck scale.

Elastically Decoupling Dark Matter.

PubMed

Kuflik, Eric; Perelstein, Maxim; Lorier, Nicolas Rey-Le; Tsai, Yu-Dai

2016-06-03

We present a novel dark matter candidate, an elastically decoupling relic, which is a cold thermal relic whose present abundance is determined by the cross section of its elastic scattering on standard model particles. The dark matter candidate is predicted to have a mass ranging from a few to a few hundred MeV, and an elastic scattering cross section with electrons, photons and/or neutrinos in the 10^{-3}-1  fb range.

RELICS Discovery of a Probable Lens-magnified SN behind Galaxy Cluster Abell 1763

NASA Astrophysics Data System (ADS)

Rodney, S.; Coe, D.; Bradley, L.; Strolger, L.; Brammer, G.; Avila, R.; Ryan, R.; Ogaz, S.; Riess, A.; Sharon, K.; Johnson, T.; Paterno-Mahler, R.; Molino, A.; Graham, M.; Kelly, P.; Filippenko, A.; Frye, B.; Foley, R.; Schmidt, K.; Umetsu, K.; Czakon, N.; Weiner, B.; Stark, D.; Mainali, R.; Zitrin, A.; Sendra, I.; Graur, O.; Grillo, C.; Hjorth, J.; Selsing, J.; Christensen, L.; Rosati, P.; Nonino, M.; Balestra, I.; Vulcani, B.; McCully, C.; Dawson, W.; Bouwens, R.; Lam, D.; Trenti, M.; Nunez, D. Carrasco; Matheson, T.; Merten, J.; Jha, S.; Jones, C.; Andrade-Santos, F.; Salmon, B.; Bradac, M.; Hoag, A.; Huang, K.; Wang, X.; Oesch, P.

2016-07-01

We report the discovery of a likely supernova (SN) in the background field of the galaxy cluster Abell 1763 (a.k.a. RXC J1335.3+4059, ZwCl 1333.7+4117). The SN candidate was detected in Hubble Space Telescope (HST) observations collected on June 17, 2016 as part of the Reionization Lensing Cluster Survey (RELICS, HST program ID: 14096, PI: D.Coe).

Shock Heating of the Merging Galaxy Cluster A521

NASA Technical Reports Server (NTRS)

Bourdin, H.; Mazzotta, P.; Markevitch, M.; Giacintucci, S.; Brunetti, G.

2013-01-01

A521 is an interacting galaxy cluster located at z = 0.247, hosting a low-frequency radio halo connected to an eastern radio relic. Previous Chandra observations hinted at the presence of an X-ray brightness edge at the position of the relic, which may be a shock front. We analyze a deep observation of A521 recently performed with XMM-Newton in order to probe the cluster structure up to the outermost regions covered by the radio emission. The cluster atmosphere exhibits various brightness and temperature anisotropies. In particular, two cluster cores appear to be separated by two cold fronts. We find two shock fronts, one that was suggested by Chandra and that is propagating to the east, and another to the southwestern cluster outskirt. The two main interacting clusters appear to be separated by a shock-heated region, which exhibits a spatial correlation with the radio halo. The outer edge of the radio relic coincides spatially with a shock front, suggesting that this shock is responsible for the generation of cosmic-ray electrons in the relic. The propagation direction and Mach number of the shock front derived from the gas density jump, M = 2.4 +/- 0.2, are consistent with expectations from the radio spectral index, under the assumption of Fermi I acceleration mechanism.

Direct detection of projectile relics from the end of the lunar basin-forming epoch.

PubMed

Joy, Katherine H; Zolensky, Michael E; Nagashima, Kazuhide; Huss, Gary R; Ross, D Kent; McKay, David S; Kring, David A

2012-06-15

The lunar surface, a key proxy for the early Earth, contains relics of asteroids and comets that have pummeled terrestrial planetary surfaces. Surviving fragments of projectiles in the lunar regolith provide a direct measure of the types and thus the sources of exogenous material delivered to the Earth-Moon system. In ancient [>3.4 billion years ago (Ga)] regolith breccias from the Apollo 16 landing site, we located mineral and lithologic relics of magnesian chondrules from chondritic impactors. These ancient impactor fragments are not nearly as diverse as those found in younger (3.4 Ga to today) regolith breccias and soils from the Moon or that presently fall as meteorites to Earth. This suggests that primitive chondritic asteroids, originating from a similar source region, were common Earth-Moon-crossing impactors during the latter stages of the basin-forming epoch.

Dark matter relics and the expansion rate in scalar-tensor theories

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dutta, Bhaskar; Jimenez, Esteban; Zavala, Ivonne, E-mail: dutta@physics.tamu.edu, E-mail: este1985@physics.tamu.edu, E-mail: e.i.zavalacarrasco@swansea.ac.uk

We study the impact of a modified expansion rate on the dark matter relic abundance in a class of scalar-tensor theories. The scalar-tensor theories we consider are motivated from string theory constructions, which have conformal as well as disformally coupled matter to the scalar. We investigate the effects of such a conformal coupling to the dark matter relic abundance for a wide range of initial conditions, masses and cross-sections. We find that exploiting all possible initial conditions, the annihilation cross-section required to satisfy the dark matter content can differ from the thermal average cross-section in the standard case. We alsomore » study the expansion rate in the disformal case and find that physically relevant solutions require a nontrivial relation between the conformal and disformal functions. We study the effects of the disformal coupling in an explicit example where the disformal function is quadratic.« less

Asymptotic analysis of the Boltzmann equation for dark matter relics in the presence of a running dilaton and space-time defects

NASA Astrophysics Data System (ADS)

Bender, Carl M.; Mavromatos, Nick E.; Sarkar, Sarben

2013-03-01

The interplay of dilatonic effects in dilaton cosmology and stochastic quantum space-time defects within the framework of string/brane cosmologies is examined. The Boltzmann equation describes the physics of thermal dark-matter-relic abundances in the presence of rolling dilatons. These dilatons affect the coupling of stringy matter to D-particle defects, which are generic in string theory. This coupling leads to an additional source term in the Boltzmann equation. The techniques of asymptotic matching and boundary-layer theory, which were recently applied by two of the authors (Bender and Sarkar) to a Boltzmann equation, are used here to find the detailed asymptotic relic abundances for all ranges of the expectation value of the dilaton field. The phenomenological implications for the search for supersymmetric dark matter in current colliders, such as the LHC, are discussed.

Advanced development of non-discoloring EVA-based PV encapsulants

DOE Office of Scientific and Technical Information (OSTI.GOV)

Holley, W.H.; Galica, J.P.; Argo, S.C.

1996-01-01

The purpose of this investigation was to better define the problem of field yellowing of EVA-based PV encapsulant, through laboratory study of probable chemical mechanisms and the development of stabilization strategies for protecting EVA from discoloration. EVA from fielded modules was analyzed for vinyl acetate content, unsaturation, and additive levels. These test results were then compared to results from Xenon Arc Weather-Ometer aged glass/EVA/glass laminates made in the laboratory. Variables evaluated in Weather-Ometer aged laminates included ``standard-cure`` A9918P EVA, ``fast-cure`` 15295P EVA, low iron glass superstrate containing cerium oxide, and systematic elimination or addition of specific additives. Six significant findingsmore » were revealed: 1) Improved ``standard-cure`` and ``fast-cure`` type EVA encapsulants, formulations X9903P and X15303P, respectively, showed little or no yellowing after extended Weather-Ometer exposure; 2) The use of {open_quote}{open_quote}fast-cure{close_quote}{close_quote} EVA reduced discoloration when compared with {open_quote}{open_quote}standard-cure{close_quote}{close_quote} A9918P EVA; 3) Glass superstrate containing cerium oxide resulted in a reduced rate of EVA discoloration; 4) {open_quote}{open_quote}Fast-cure{close_quote}{close_quote} EVA used with glass superstrate containing cerium oxide showed no visible yellowing after 32 weeks in the Weather-Ometer{emdash}a period estimated to be roughly equivalent to 20{endash}30 years of exposure in the Southwest; 5) Severely discolored EVA samples from the field showed no measurable loss of acetate group and little detectable unsaturation; and 6) EVA encapsulant with a Tefzel cover exhibited no yellowing after extended Weather-Ometer exposure. {copyright} {ital 1996 American Institute of Physics.}« less

Constraints on Resonant Dark Matter Annihilation

NASA Astrophysics Data System (ADS)

Backovic, Mihailo

Resonant dark matter annihilation drew much attention in the light of recent measurements of charged cosmic ray fluxes. Interpreting the anomalous signal in the positron fraction as a sign of dark matter annihilation in the galactic halo requires cross sections orders of magnitudes higher than the estimates coming from thermal relic abundance. Resonant dark matter annihilation provides a mechanism to bridge the apparent contradiction between thermal relic abundance and the positron data measured by PAMELA and FERMI satellites. In this thesis, we analyze a class of models which allow for dark matter to annihilate through an s-channel resonance. Our analysis takes into account constraints from thermal relic abundance and the recent measurements of charged lepton cosmic ray fluxes, first separately and then simultaneously. Consistency of resonant dark matter annihilation models with thermal relic abundance as measured by WMAP serves to construct a relationship between the full set of masses, couplings and widths involved. Extensive numerical analysis of the full four dimensional parameter space is summarized by simple analytic approximations. The expressions are robust enough to be generalized to models including additional annihilation channels. We provide a separate treatment of resonant annihilation of dark matter in the galac- tic halo. We find model-independent upper limits on halo dark matter annihilation rates and show that the most efficient annihilation mechanism involves s-channel resonances. Widths that are large compared to the energy spread in the galactic halo are capable of saturating unitarity bounds without much difficulty. Partial wave unitarity prevents the so called Sommerfeld factors from producing large changes in cross sections. In addition, the approximations made in Sommerfeld factors break down in the kinematic regions where large cross section enhancements are often cited. Simultaneous constraints from thermal relic abundance and halo annihilation serve to produce new limits on dark matter masses and couplings. Past considerations of only a part of the resonant annihilation parameter set to motivate large annihilation cross section enhancements in the halo while maintaining correct relic abundance are generally incomplete. Taking into account only the resonance mass and width to show that large cross section enhancements are possible does not in principle guarantee that the enhancement will be achieved. We extend the calculation to include the full resonant parameter set. As a result, we obtain new limits on dark matter masses and couplings.

Biohistorical materials and contemporary privacy concerns-the forensic case of King Albert I.

PubMed

Larmuseau, Maarten H D; Bekaert, Bram; Baumers, Maarten; Wenseleers, Tom; Deforce, Dieter; Borry, Pascal; Decorte, Ronny

2016-09-01

The rapid advancement of technology in genomic analysis increasingly allows researchers to study human biohistorical materials. Nevertheless, little attention has been paid to the privacy of the donor's living relatives and the negative impact they might experience from the (public) availability of genetic results, even in cases of scientific, forensic or historical relevance. This issue has become clear during a cold case investigation of a relic attributed to Belgian King and World War I-hero Albert I who died, according to the official version, in a solo climbing accident in 1934. Authentication of the relic with blood stains assigned to the King and collected on the place where his body was discovered is recognised as one of the final opportunities to test the plausibility of various conspiracy theories on the King's demise. While the historical value and current technological developments allow the genomic analysis of this relic, publication of genetic data would immediately lead to privacy concerns for living descendants and relatives of the King, including the Belgian and British royal families, even after more than 80 years. Therefore, the authentication study of the relic of King Albert I has been a difficult exercise towards balancing public research interests and privacy interests. The identification of the relic was realised by using a strict genetic genealogical approach including Y-chromosome and mitochondrial genome comparison with living relatives, thereby limiting the analysis to genomic regions relevant for identification. The genetic results combined with all available historical elements concerning the relic, provide strong evidence that King Albert I was indeed the donor of the blood stains, which is in line with the official climbing accident hypothesis and contradicts widespread 'mise-en-scène' scenarios. Since publication of the haploid data of the blood stains has the potential to violate the privacy of living relatives, we opted for external and independent reviewing of (the quality of) our data and statistical interpretation by external forensic experts in haploid markers to guarantee the objectivity and scientific accuracy of the identification data analysis as well as the privacy of living descendants and relatives. Although the cold case investigation provided relevant insights into the circumstances surrounding the death of King Albert I, it also revealed the insufficient ethical guidance for current genomic studies of biohistorical material. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Relic gravitational waves and extended inflation

NASA Technical Reports Server (NTRS)

Turner, Michael S.; Wilczek, Frank

1990-01-01

In extended inflation, a new version of inflation where the transition from an inflationary to a radiation-dominated universe is accomplished by bubble nucleation, bubble collisions supply a potent - and potentially detectable - source of gravitational waves. The energy density in relic gravitons from bubble collisions is expected to be about 0.00005 of closure density. Their characteristic wavelength depends on the reheating temperature. If black holes are produced by bubble collisions, they will evaporate, producing shorter-wavelength gravitons.

Tachyons in the Galilean limit

NASA Astrophysics Data System (ADS)

Batlle, Carles; Gomis, Joaquim; Mezincescu, Luca; Townsend, Paul K.

2017-04-01

The Souriau massless Galilean particle of "colour" k and spin s is shown to be the Galilean limit of the Souriau tachyon of mass m = ik and spin s. We compare and contrast this result with the Galilean limit of the Nambu-Goto string and Green-Schwarz superstring.

Stochastic background from cosmic (super)strings: Popcorn-like and (Gaussian) continuous regimes

NASA Astrophysics Data System (ADS)

Regimbau, Tania; Giampanis, Stefanos; Siemens, Xavier; Mandic, Vuk

2012-03-01

In the era of the next generation of gravitational wave experiments a stochastic background from cusps of cosmic (super)strings is expected to be probed and, if not detected, to be significantly constrained. A popcornlike background can be, for part of the parameter space, as pronounced as the (Gaussian) continuous contribution from unresolved sources that overlap in frequency and time. We study both contributions from unresolved cosmic string cusps over a range of frequencies relevant to ground based interferometers, such as the LIGO/Virgo second generation and Einstein Telescope third generation detectors, the space antenna LISA, and pulsar timing arrays. We compute the sensitivity (at the 2σ level) in the parameter space for the LIGO/Virgo second generation detector, the Einstein Telescope detector, LISA, and pulsar timing arrays. We conclude that the popcorn regime is complementary to the continuous background. Its detection could therefore enhance confidence in a stochastic background detection and possibly help determine fundamental string parameters such as the string tension and the reconnection probability.

Open superstring field theory based on the supermoduli space

NASA Astrophysics Data System (ADS)

Ohmori, Kantaro; Okawa, Yuji

2018-04-01

We present a new approach to formulating open superstring field theory based on the covering of the supermoduli space of super-Riemann surfaces and explicitly construct a gauge-invariant action in the Neveu-Schwarz sector up to quartic interactions. The cubic interaction takes a form of an integral over an odd modulus of disks with three punctures and the associated ghost is inserted. The quartic interaction takes a form of an integral over one even modulus and two odd moduli, and it can be interpreted as the integral over the region of the supermoduli space of disks with four punctures which is not covered by Feynman diagrams with two cubic vertices and one propagator. As our approach is based on the covering of the supermoduli space, the resulting theory naturally realizes an A ∞ structure, and the two-string product and the three-string product used in defining the cubic and quartic interactions are constructed to satisfy the A ∞ relations to this order.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pern, F.J.; Glick, S.H.

We have conducted a series of accelerated exposure test (AET) studies for various crystalline-Si (c-Si) and amorphous-Si (a-Si) cell samples that were encapsulated with different superstrates, pottants, and substrates. Nonuniform browning patterns of ethylene vinyl acetate (EVA) pottants were observed for glass/EVA/glass-encapsulated c-Si cell samples under solar simulator exposures at elevated temperatures. The polymer/polymer-configured laminates with Tedlar or Tefzel did not discolor because of photobleaching reactions, but yellowed with polyester or nylon top films. Delamination was observed for the polyester/EVE layers on a-Si minimodules and for a polyolefin-based thermoplastic pottant at high temperatures. For all tested c-Si cell samples, irregularmore » changes in the current-voltage parameters were observed that could not be accounted for simply by the transmittance changes of the superstrate/pottant layers. Silicone-type adhesives used under UV-transmitting polymer top films were observed to cause greater cell current/efficiency loss than EVA or polyethylene pottants. {copyright} {ital 1999 American Institute of Physics.}« less

PhD Thesis: String theory in the early universe

NASA Astrophysics Data System (ADS)

Gwyn, Rhiannon

2009-11-01

The intersection of string theory with cosmology is unavoidable in the early universe, and its exploration may shine light on both fields. In this thesis, three papers at this intersection are presented and reviewed, with the aim of providing a thorough and pedagogical guide to their results. First, we address the longstanding problem of finding a string theory realisation of the axion. Using warped compactifications in heterotic string theory, we show that the axion decay constant can be lowered to acceptable values by the warp factor. Next, we move to the subject of cosmic strings, whose network evolution could have important consequences for astrophysics and cosmology. In particular, there are quantitative differences between cosmic superstring networks and GUT cosmic string networks. We investigate the properties of cosmic superstring networks in warped backgrounds, giving the tension and properties of three-string junctions in these backgrounds. Finally, we examine the possibility that cosmic strings in heterotic string theory could be responsible for generating the galactic magnetic fields that seeded those observed today.

Noble Gases in the Murchison Meteorite: Possible Relics of s-Process Nucleosynthesis.

PubMed

Srinivasan, B; Anders, E

1978-07-07

The Murchison carbonaceous chondrite contains a new type of xenon component, enriched by up to 50 percent in five of the nine stable xenon isotopes, mass numbers 128 to 132. This component, comprising 5 x 10(-5) of the total xenon in the meteorite, is released at 1200 degrees to 1600 degrees C from a severely etched mineral fraction, and probably resides in some refractory mineral. Krypton shows a similar but smaller enrichment in the isotopes 80 and 82. Neon and helium released in the same interval also are quite anomalous, being highly enriched in the isotopes 22 and 3. These patterns are strongly suggestive of three nuclear processes believed to take place in red giants: the s process (neutron capture on a slow time scale), helium burning, and hydrogen shell burning. If this interpretation is correct, then primitive meteorites contain yet another kind of alien, presolar material: dust grains ejected from red giants.

Multicomponent Dark Matter in Radiative Seesaw Models

NASA Astrophysics Data System (ADS)

Aoki, Mayumi; Kaneko, Daiki; Kubo, Jisuke

2017-11-01

We discuss radiative seesaw models, in which an exact Z_2¥times Z_2' symmetry is imposed. Due to the exact Z_2¥times Z_2' symmetry, neutrino masses are generated at a two-loop level and at least two extra stable electrically neutral particles are predicted. We consider two models: one has a multi-component dark matter system and the other one has a dark radiation in addition to a dark matter. In the multi-component dark matter system, non-standard dark matter annihilation processes exist. We find that they play important roles in determining the relic abundance and also responsible for the monochromatic neutrino lines resulting from the dark matter annihilation process. In the model with the dark radiation, the structure of the Yukawa coupling is considerably constrained and gives an interesting relationship among cosmology, lepton flavor violating decay of the charged leptons and the decay of the inert Higgs bosons.

Supersymmetric relics from the big bang

DOE PAGES

Ellis, John; Hagelin, J. S.; Nanopoulos, D. V.; ...

1984-06-01

In this paper, we consider the cosmological constraints on supersymmetric theories with a new, stable particle. Circumstantial evidence points to a neutral gauge/Higgs fermion as the best candidate for this particle, and we derive bounds on the parameters in the lagrangian which govern its mass and couplings. One favored possibility is that the lightest neutral supersymmetric particle is predominantly a photino ~γ with mass above 12 GeV, while another is that the lightest neutral supersymmetric particle is a Higgs fermion with mass above 5 GeV or less than O(100) eV. We also point out that a gravitino mass of 10more » to 100 GeV implies that the temperature after completion of an inflationary phase cannot be above 10 14 GeV, and probably not above 3 × 10 12 GeV. Finally, this imposes constraints on mechanisms for generating the baryon number of the universe.« less

The Higgs seesaw induced neutrino masses and dark matter

DOE PAGES

Cai, Yi; Chao, Wei

2015-08-12

In this study we propose a possible explanation of the active neutrino Majorana masses with the TeV scale new physics which also provide a dark matter candidate. We extend the Standard Model (SM) with a local U(1)' symmetry and introduce a seesaw relation for the vacuum expectation values (VEVs) of the exotic scalar singlets, which break the U(1)' spontaneously. The larger VEV is responsible for generating the Dirac mass term of the heavy neutrinos, while the smaller for the Majorana mass term. As a result active neutrino masses are generated via the modified inverse seesaw mechanism. The lightest of themore » new fermion singlets, which are introduced to cancel the U(1)' anomalies, can be a stable particle with ultra flavor symmetry and thus a plausible dark matter candidate. We explore the parameter space with constraints from the dark matter relic abundance and dark matter direct detection.« less

The return of the merging galaxy subclusters of El Gordo?

DOE PAGES

Ng, Karen Y.; Dawson, William A.; Wittman, D.; ...

2015-08-25

Merging galaxy clusters with radio relics provide rare insights to the merger dynamics as the relics are created by the violent merger process. We demonstrate one of the first uses of the properties of the radio relic to reduce the uncertainties of the dynamical variables and determine the three-dimensional (3D) configuration of a cluster merger, ACT-CL J0102-4915, nicknamed El Gordo. From the double radio relic observation and the X-ray observation of a comet-like gas morphology induced by motion of the cool core, it is widely believed that El Gordo is observed shortly after the first core passage of the subclusters. Here, we employ a Monte Carlo simulation to investigate the 3D configuration and dynamics of El Gordo. Using the polarization fraction of the radio relic, we constrain the estimate of the angle between the plane of the sky and the merger axis to be α=21°±more » $$9\\atop{11}$$. We find the relative 3D merger speed of El Gordo to be 2400 ± $$400\\atop{200}$$ km s -1 at pericentre. The two possible estimates of the time since pericentre (TSP) are 0.46 ± $$0.09\\atop{0.16}$$ and 0.91± $$0.22\\atop{0.39}$$ Gyr for the outgoing and returning scenario, respectively. We put our estimates of the TSP into context by showing that if the time-averaged shock velocity is approximately equal to or smaller than the pericentre velocity of the corresponding subcluster in the centre-of-mass frame, the two subclusters are more likely to be moving towards, rather than away, from each other, post apocentre. Finally, we compare and contrast the merger scenario of El Gordo with that of the Bullet Cluster, and show that this late-stage merging scenario explains why the south-east (SE) dark matter lensing peak of El Gordo is closer to the merger centre than the SE cool core.« less

The return of the merging galaxy subclusters of El Gordo?

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ng, Karen Y.; Dawson, William A.; Wittman, D.

Merging galaxy clusters with radio relics provide rare insights to the merger dynamics as the relics are created by the violent merger process. We demonstrate one of the first uses of the properties of the radio relic to reduce the uncertainties of the dynamical variables and determine the three-dimensional (3D) configuration of a cluster merger, ACT-CL J0102-4915, nicknamed El Gordo. From the double radio relic observation and the X-ray observation of a comet-like gas morphology induced by motion of the cool core, it is widely believed that El Gordo is observed shortly after the first core passage of the subclusters. Here, we employ a Monte Carlo simulation to investigate the 3D configuration and dynamics of El Gordo. Using the polarization fraction of the radio relic, we constrain the estimate of the angle between the plane of the sky and the merger axis to be α=21°±more » $$9\\atop{11}$$. We find the relative 3D merger speed of El Gordo to be 2400 ± $$400\\atop{200}$$ km s -1 at pericentre. The two possible estimates of the time since pericentre (TSP) are 0.46 ± $$0.09\\atop{0.16}$$ and 0.91± $$0.22\\atop{0.39}$$ Gyr for the outgoing and returning scenario, respectively. We put our estimates of the TSP into context by showing that if the time-averaged shock velocity is approximately equal to or smaller than the pericentre velocity of the corresponding subcluster in the centre-of-mass frame, the two subclusters are more likely to be moving towards, rather than away, from each other, post apocentre. Finally, we compare and contrast the merger scenario of El Gordo with that of the Bullet Cluster, and show that this late-stage merging scenario explains why the south-east (SE) dark matter lensing peak of El Gordo is closer to the merger centre than the SE cool core.« less

MC 2: Mapping the dark matter distribution of the “Toothbrush” cluster RX J0603.3+4214 with Hubble Space Telescope and Subaru weak lensing

DOE PAGES

Jee, M. James; Dawson, William A.; Stroe, Andra; ...

2016-02-01

The galaxy cluster RX J0603.3+4214 at z = 0:225 is one of the rarest clusters boasting an extremely large ( 2 Mpc) radio relic. Because of the remarkable morphology of the relic, the cluster is nicknamed the \\Toothbrush Cluster". Although the cluster's underlying mass distribution is one of the critical pieces of information needed to reconstruct the merger scenario responsible for the puzzling radio relic morphology, its proximity to the Galactic plane b 10 has imposed signi cant observational challenges. We present a high-resolution weak-lensing study of the cluster with Subaru/Suprime Cam and Hubble Space Telescope imaging data. Our massmore » reconstruction reveals that the cluster is composed of complicated dark matter substructures closely tracing the galaxy distribution, in contrast, however, with the relatively simple binary X-ray morphology. Nevertheless, we nd that the cluster mass is still dominated by the two most massive clumps aligned north-south with a 3:1 mass ratio (M 200 = 6:29 +2:24 -1:62 X 10 14M⊙ and 1:98 +1:24 -0:74 X 10 14M⊙ for the northern and southern clumps, respectively). The southern mass peak is 20 o set toward the south with respect to the corresponding X-ray peak, which has a \\bullet"-like morphology pointing south. Comparison of the current weak- lensing result with the X-ray, galaxy, and radio relic suggests that perhaps the dominant mechanism responsible for the observed relic may be a high-speed collision of the two most massive subclusters, although the peculiarity of the morphology necessitates involvement of additional subclusters. Careful numerical simulations should follow in order to obtain more complete understanding of the merger scenario utilizing all existing observations.« less

Relic keV sterile neutrinos and reionization.

PubMed

Biermann, Peter L; Kusenko, Alexander

2006-03-10

A sterile neutrino with a mass of several keV can account for cosmological dark matter, as well as explain the observed velocities of pulsars. We show that x rays produced by the decays of these relic sterile neutrinos can boost the production of molecular hydrogen, which can speed up the cooling of gas and the early star formation, which can, in turn, lead to a reionization of the Universe at a high enough redshift to be consistent with the Wilkinson Microwave Anisotropy Probe results.

Informational biopolymer structure in early living forms.

NASA Technical Reports Server (NTRS)

Dayhoff, M. O.; Mclaughlin, P. J.; Barker, W. C.; Hunt, L. T.

1972-01-01

Some studies devoted to the search in various organisms for 'relics' of the biochemical nature of ancient organisms, preserved by the conservative nature of the evolutionary process in all living species, are reviewed. Investigations of five families of informational molecules constituting such 'relics' in very diverse organisms are reported. They include: cytochrome c, ferredoxin, trypsin, transfer ribonucleic acid (RNA), and 5S ribosomal RNA. It is shown that, even from these few informational molecules, some interesting inferences about early living organisms can be drawn.

Special Holonomy and Two-Dimensional Supersymmetric Sigma-Models

NASA Astrophysics Data System (ADS)

Stojevic, Vid

2006-11-01

Two-dimensional sigma-models describing superstrings propagating on manifolds of special holonomy are characterized by symmetries related to covariantly constant forms that these manifolds hold, which are generally non-linear and close in a field dependent sense. The thesis explores various aspects of the special holonomy symmetries.

The Rising Landscape: A Visual Exploration of Superstring Revolutions in Physics.

ERIC Educational Resources Information Center

Chen, Chaomei; Kuljis, Jasna

2003-01-01

Discussion of knowledge domain visualization focuses on practical issues concerning modeling and visualizing scientific revolutions. Studies growth patterns of specialties derived from citation and cocitation data on string theory in physics, using the general framework of Thomas Kuhn's structure of scientific revolutions. (Author/LRW)

Cosmic selection rule for the glueball dark matter relic density

NASA Astrophysics Data System (ADS)

Soni, Amarjit; Xiao, Huangyu; Zhang, Yue

2017-10-01

We point out a unique mechanism to produce the relic abundance for the glueball dark matter from a gauged SU (N )d hidden sector which is bridged to the standard model sector through heavy vectorlike quarks colored under gauge interactions from both sides. A necessary ingredient of our assumption is that the vectorlike quarks, produced either thermally or nonthermally, are abundant enough to dominate the universe for some time in the early universe. They later undergo dark color confinement and form unstable vectorlike-quarkonium states which annihilate decay and reheat the visible and dark sectors. The ratio of entropy dumped into two sectors and the final energy budget in the dark glueballs is only determined by low energy parameters, including the intrinsic scale of the dark SU (N )d , Λd, and number of dark colors, Nd, but depend weakly on parameters in the ultraviolet such as the vectorlike quark mass or the initial condition. We call this a cosmic selection rule for the glueball dark matter relic density.

Biospheric traumas caused by large impacts and predicted relics in the sedimentary record

NASA Technical Reports Server (NTRS)

Prinn, R. G.; Fegley, B., Jr.

1988-01-01

When a large asteroid or comet impacts the Earth the supersonic plume ejected on impact causes severe shock heating and chemical reprocessing of the proximal atmosphere. The resultant NO is converted rapidly to NO2, foliage damage due to exposure to NO2 and HNO3, toxicosis resulting from massive mobilization of soil trace metals, and faunal asphyxiation due to exposure to NO2. One class of relic evidence for the above effects arises because extinction of species caused by these chemically induced traumas would be selective. A second class of relic evidence arises because the acid rain will cause massive weathering of continental rocks and soils characterized by large ratios of the relatively insoluble metals, to the more soluble metals. This weathering would be best recorded in fossils in unperturbed deltaic, neritic, or limnetic sediments and for metals with very long oceanic residence times in deep ocean sediments as well. This evidence is discussed.

Biospheric traumas caused by large impacts and predicted relics in the sedimentary record

NASA Astrophysics Data System (ADS)

Prinn, R. G.; Fegley, B., Jr.

When a large asteroid or comet impacts the Earth the supersonic plume ejected on impact causes severe shock heating and chemical reprocessing of the proximal atmosphere. The resultant NO is converted rapidly to NO2, foliage damage due to exposure to NO2 and HNO3, toxicosis resulting from massive mobilization of soil trace metals, and faunal asphyxiation due to exposure to NO2. One class of relic evidence for the above effects arises because extinction of species caused by these chemically induced traumas would be selective. A second class of relic evidence arises because the acid rain will cause massive weathering of continental rocks and soils characterized by large ratios of the relatively insoluble metals, to the more soluble metals. This weathering would be best recorded in fossils in unperturbed deltaic, neritic, or limnetic sediments and for metals with very long oceanic residence times in deep ocean sediments as well. This evidence is discussed.

Architecture design of the national plant treasure management information system based on GIS: a case study of Gugong Date Garden in Hebei province

NASA Astrophysics Data System (ADS)

Shen, Shaoling; Li, Renjie; Shen, Dongdong; Tong, Chunyan; Fu, Xueqing

2007-06-01

"Gugong Date Garden", lies in Juguan Village, Qijiawu County, Huanghua City, China. It is the largest forest of winter date in this world, which is the longest in history, largest in area and best in quality and it is also included in the first group of national main protected units of botanic cultural relics. However, it is lacking of uniform management platform and modes. According to the specific characteristics of botanic cultural relics preservation, the author sets up the "Plant Treasure Management Information System" for "Gugong Date Garden", based on the Geographic information system (GIS), Internet, database and virtual reality technologies, along with the idea of modern customer management systems. This system is designed for five types of users, named system administrators, cultural relic supervisors, researchers, farmers and tourists, with the aim of realizing integrated managements of ancient trees' protection, scientific researches, tourism and explorations altogether, so as to make better management, protection, and utilizations.

Identification and analysis of unitary loss of long-established protein-coding genes in Poaceae shows evidences for biased gene loss and putatively functional transcription of relics.

PubMed

Zhao, Yi; Tang, Liang; Li, Zhe; Jin, Jinpu; Luo, Jingchu; Gao, Ge

2015-04-18

Long-established protein-coding genes may lose their coding potential during evolution ("unitary gene loss"). Members of the Poaceae family are a major food source and represent an ideal model clade for plant evolution research. However, the global pattern of unitary gene loss in Poaceae genomes as well as the evolutionary fate of lost genes are still less-investigated and remain largely elusive. Using a locally developed pipeline, we identified 129 unitary gene loss events for long-established protein-coding genes from four representative species of Poaceae, i.e. brachypodium, rice, sorghum and maize. Functional annotation suggested that the lost genes in all or most of Poaceae species are enriched for genes involved in development and response to endogenous stimulus. We also found that 44 mutated genomic loci of lost genes, which we referred as relics, were still actively transcribed, and of which 84% (37 of 44) showed significantly differential expression across different tissues. More interestingly, we found that there were totally five expressed relics may function as competitive endogenous RNA in brachypodium, rice and sorghum genome. Based on comparative genomics and transcriptome data, we firstly compiled a comprehensive catalogue of unitary gene loss events in Poaceae species and characterized a statistically significant functional preference for these lost genes as well showed the potential of relics functioning as competitive endogenous RNAs in Poaceae genomes.

[Using IRAP markers for analysis of genetic variability in populations of resource and rare species of plants].

PubMed

Boronnikova, S V; Kalendar', R N

2010-01-01

Species-specific LTR retrotransposons were first cloned in five rare relic species of drug plants located in the Perm' region. Sequences of LTR retrotransposons were used for PCR analysis based on amplification of repeated sequences from LTR or other sites of retrotransposons (IRAP). Genetic diversity was studied in six populations of rare relic species of plants Adonis vernalis L. by means of the IRAP method; 125 polymorphic IRAP-markers were analyzed. Parameters for DNA polymorphism and genetic diversity of A. vernalis populations were determined.

Higgs enhancement for the dark matter relic density

NASA Astrophysics Data System (ADS)

Harz, Julia; Petraki, Kalliopi

2018-04-01

We consider the long-range effect of the Higgs on the density of thermal-relic dark matter. While the electroweak gauge boson and gluon exchange have been previously studied, the Higgs is typically thought to mediate only contact interactions. We show that the Sommerfeld enhancement due to a 125 GeV Higgs can deplete TeV-scale dark matter significantly and describe how the interplay between the Higgs and other mediators influences this effect. We discuss the importance of the Higgs enhancement in the minimal supersymmetric standard model and its implications for experiments.

Neutrinophilic two Higgs doublet model with dark matter under an alternative U(1)_{B-L} gauge symmetry

NASA Astrophysics Data System (ADS)

Nomura, Takaaki; Okada, Hiroshi

2018-03-01

We propose a Dirac type active neutrino with rank two mass matrix and a Majorana fermion dark matter candidate with an alternative local U(1)_{B-L} extension of neutrinophilic two Higgs doublet model. Our dark matter candidate can be stabilized due to charge assignment under the gauge symmetry without imposing extra discrete Z_2 symmetry and the relic density is obtained from an Z' boson exchanging process. Taking into account collider constraints on the Z' boson mass and coupling, we estimate the relic density.

[Damage to ancient mural paintings and petroglyphs caused by Pseudonocardia sp. - A review].

PubMed

Pan, Xiaoxuan; Ge, Qinya; Pan, Jiao

2015-07-04

The historical relics exposed to the natural environment during the long-term were vulnerable to microbial invasion. According to some new studies, microorganism of Pseudonocardia may is one of the main groups on the surface of mural paintings and petroglyphs, causing damage to the paints. Based on recent research progress, we reviewed the phenomenon according to the relationship between the ancient paintings and the growth conditions of Pseudonocardia, which could provide a new theory basis for the protection of cultural relics especially mural paintings and petroglyphs.

The Biggest Bangs Since the Big Bang: Unveiling Mergers of Galaxy Clusters with Radio Halos/Relics Using X-ray Temperature Maps

NASA Astrophysics Data System (ADS)

Burns, Jack

Galaxy clusters are assembled through large and small mergers which are the most energetic events ( bangs ) since the Big Bang. Cluster mergers stir the ICM creating shocks and turbulence which are illuminated by Mpc-sized radio features called relics and halos. These shocks heat the ICM and are detected in x-rays via thermal emission. Disturbed morphologies in x-ray surface brightness and temperatures are direct evidence for cluster mergers. In the radio, relics (in the outskirts of the clusters) and halos (located near the cluster core) are clear signposts of recent mergers. Our recent cosmological simulations suggest that around a merger event, radio emission peaks very sharply (and briefly) while the x-ray emission rises and decays slowly. Hence, a sample of galaxy clusters that shows both luminous x-ray and radio relics/halos are clear candidates for very recent mergers. We propose to analyze a unique sample of 48 galaxy clusters with (i) known radio relics and/or halos and (ii) significant archival x-ray observations (e 50 ksec) from Chandra and/or XMM. We will use a new x-ray data analysis pipeline, implemented on a parallelprocessor supercomputer, to create x-ray surface brightness, high fidelity temperature, and pressure maps of these clusters in order to study merging activity. In addition, we will use a control sample of clusters from the HIFLUGCS catalog which do not show radio relics/halos or any significant x-ray surface brightness substructure, thus devoid of recent mergers. The temperature maps will be made using 3 different map-making techniques: Weighted Voronoi Tessellation, Adaptive Circular Binning, and Contour Binning. We also plan to use archival Suzaku data for 22 clusters in our sample and study the x-ray temperatures at the outskirts of the clusters. All 48 clusters have archival radio data at d1.4 GHz which will be re-analyzed using advanced algorithms in NRAO s CASA software. We also have new radio data on a subset of these clusters and have proposed to observe more of them with the increased sensitivity of the JVLA and GMRT at 0.25-1.4 GHz. Using the systematically analyzed x-ray and radio data, we propose to pursue the detailed link between cluster mergers and the formation of radio relics/halos. (a) How do radio relics form? Radio relics are believed to be created via re-acceleration of cosmic ray electrons through diffusive shock acceleration, a 1st order Fermi mechanism. Hence, there should be a correlation between shocks detected in the x-ray and radio. We plan to use our newly developed 2-D shock-finder using jumps within xray temperature maps, and complement the results with radio Mach numbers derived from radio spectral indices. Shocks detected in our simulations using a 3-D shock-finder will be used to understand the effects of projections in observations. (b) How do radio halos form? It is not clear if the formation of radio halos is due to turbulent acceleration (2nd order Fermi process) or due to more efficient 1st order Fermi mechanism via distributed small-scale shocks. Since radio halos reside in merging clusters, the x-ray temperature structure should show the un-relaxed nature of the cluster. We will study this through temperature asymmetry and power ratios (between two multipoles). We also propose to use pressure maps to derive a 2-D power spectrum of pressure fluctuations and deduce the turbulent velocity field. We will then derive the associated radio power and spectral indices to compare with the radio observations. We will test our results using clusters with and without radio halos. We will make these high fidelity temperature, surface brightness, pressure and entropy maps available to the astronomical community via the National Virtual Observatory. We will also make our x-ray temperature map-making scripts implemented on parallel supercomputers available for community use.

Quantization of higher abelian gauge theory in generalized differential cohomology

NASA Astrophysics Data System (ADS)

Szabo, R.

We review and elaborate on some aspects of the quantization of certain classes of higher abelian gauge theories using techniques of generalized differential cohomology. Particular emphasis is placed on the examples of generalized Maxwell theory and Cheeger-Simons cohomology, and of Ramond-Ramond fields in Type II superstring theory and differential K-theory.

Observational physics of mirror world

NASA Technical Reports Server (NTRS)

Khlopov, M. YA.; Beskin, G. M.; Bochkarev, N. E.; Pustilnik, L. A.; Pustilnik, S. A.

1989-01-01

The existence of the whole world of shadow particles, interacting with each other and having no mutual interactions with ordinary particles except gravity is a specific feature of modern superstring models, being considered as models of the theory of everything. The presence of shadow particles is the necessary condition in the superstring models, providing compensation of the asymmetry of left and right chirality states of ordinary particles. If compactification of additional dimensions retains the symmetry of left and right states, shadow world turns to be the mirror one, with particles and fields having properties strictly symmetrical to the ones of corresponding ordinary particles and fields. Owing to the strict symmetry of physical laws for ordinary and mirror particles, the analysis of cosmological evolution of mirror matter provides rather definite conclusions on possible effects of mirror particles in the universe. A general qualitative discussion of possible astronomical impact of mirror matter is given, in order to make as wide as possible astronomical observational searches for the effects of mirror world, being the unique way to test the existence of mirror partners of ordinary particles in the Nature.

Light trapping in thin-film solar cells measured by Raman spectroscopy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ledinský, M., E-mail: ledinsky@fzu.cz; Photovoltaics and Thin Film Electronics Laboratory, Institute of Microengineering; Moulin, E.

2014-09-15

In this study, Raman spectroscopy is used as a tool to determine the light-trapping capability of textured ZnO front electrodes implemented in microcrystalline silicon (μc-Si:H) solar cells. Microcrystalline silicon films deposited on superstrates of various roughnesses are characterized by Raman micro-spectroscopy at excitation wavelengths of 442 nm, 514 nm, 633 nm, and 785 nm, respectively. The way to measure quantitatively and with a high level of reproducibility the Raman intensity is described in details. By varying the superstrate texture and with it the light trapping in the μc-Si:H absorber layer, we find significant differences in the absolute Raman intensity measured in the near infraredmore » wavelength region (where light trapping is relevant). A good agreement between the absolute Raman intensity and the external quantum efficiency of the μc-Si:H solar cells is obtained, demonstrating the validity of the introduced method. Applications to thin-film solar cells, in general, and other optoelectronic devices are discussed.« less

Integrability of the Ad{{S}_{5}}\\times {{S}^{5}} superstring and its deformations

NASA Astrophysics Data System (ADS)

van Tongeren, Stijn J.

2014-10-01

This article reviews the application of integrability to the spectral problem of strings on Ad{{S}5}× {{S}5} and its deformations. We begin with a pedagogical introduction to integrable field theories culminating in the description of their finite-volume spectra through the thermodynamic Bethe ansatz (TBA). Next, we apply these ideas to the Ad{{S}5}× {{S}5} string and in later sections discuss how to account for particular integrable deformations. Through the AdS/CFT correspondence this gives an exact description of anomalous scaling dimensions of single trace operators in planar N=4 supersymmetry Yang-Mills theory, its ‘orbifolds’, and β and γ-deformed supersymmetric Yang-Mills theory. We also touch upon some subtleties arising in these deformed theories. Furthermore, we consider complex excited states (bound states) in the su(2) sector and give their TBA description. Finally we discuss the TBA for a quantum deformation of the Ad{{S}5}× {{S}5} superstring S-matrix, with close relations to among others Pohlmeyer reduced string theory, and briefly indicate more recent developments in this area.

Top-quark mass coupling and classification of weakly coupled heterotic superstring vacua

NASA Astrophysics Data System (ADS)

Rizos, J.

2014-06-01

The quest for the Standard Model among the huge number of string vacua is usually based on a set of phenomenological criteria related to the massless spectrum of string models. In this work we study criteria associated with interactions in the effective low energy theory and in particular with the presence of the coupling that provides mass to the top quark. Working in the context of the free-fermionic formulation of the heterotic superstring, we demonstrate that, in a big class of phenomenologically promising compactifications, these criteria can be expressed entirely in terms of the generalised GSO projection coefficients entering the definition of the models. They are shown to be very efficient in identifying phenomenologically viable vacua, especially in the framework of computer-based search, as they are met by approximately one every models. We apply our results in the investigation of a class of supersymmetric Pati-Salam vacua, comprising configurations, and we show that when combined with other phenomenological requirements they lead to a relatively small set of about Standard Model compatible models that can be fully classified.

Advances in all-sputtered CdTe solar cells on flexible substrates

NASA Astrophysics Data System (ADS)

Wieland, Kristopher; Mahabaduge, Hasitha; Vasko, Anthony; Compaan, Alvin

2010-03-01

The University of Toledo II-VI semiconductor group has developed magnetron sputtering (MS) for the deposition of thin films of CdS, CdTe, and related materials for photovoltaic applications. On glass superstrates, we have reached air mass 1.5 efficiencies of 14%.[1] Recently we have studied the use of MS for the fabrication of thin-film CdS/CdTe cells on flexible polyimide superstrates. This takes advantage of the high film quality that can be achieved at substrate temperatures below 300 C when RF MS is used. Our recent CdS/CdTe solar cells have reached 10.5% on flexible polyimide substrates. [2] This all-sputtered cell (except for back contact) has a structure of polyimide/ZnO:Al/ZnO/CdS/CdTe/Cu/Au. The physics of this device will be discussed through the use of spectral quantum efficiency and current-voltage measurements as a function of CdTe layer thickness. Pathways toward further increases in device efficiencies will also be discussed. [1] Appl. Phys. Lett. 85, 684 (2004) [2] Phys. Stat. Sol. (B) 241, No. 3, 779--782 (2004)

Towards generalized mirror symmetry for twisted connected sum G 2 manifolds

NASA Astrophysics Data System (ADS)

Braun, Andreas P.; Del Zotto, Michele

2018-03-01

We revisit our construction of mirror symmetries for compactifications of Type II superstrings on twisted connected sum G 2 manifolds. For a given G 2 manifold, we discuss evidence for the existence of mirror symmetries of two kinds: one is an autoequivalence for a given Type II superstring on a mirror pair of G 2 manifolds, the other is a duality between Type II strings with different chiralities for another pair of mirror manifolds. We clarify the role of the B-field in the construction, and check that the corresponding massless spectra are respected by the generalized mirror maps. We discuss hints towards a homological version based on BPS spectroscopy. We provide several novel examples of smooth, as well as singular, mirror G 2 backgrounds via pairs of dual projecting tops. We test our conjectures against a Joyce orbifold example, where we reproduce, using our geometrical methods, the known mirror maps that arise from the SCFT worldsheet perspective. Along the way, we discuss non-Abelian gauge symmetries, and argue for the generation of the Affleck-Harvey-Witten superpotential in the pure SYM case.

[Research Progress of Raman Spectroscopy on Dyestuff Identification of Ancient Relics and Artifacts].

PubMed

He, Qiu-ju; Wang, Li-qin

2016-02-01

As the birthplace of Silk Road, China has a long dyeing history. The valuable information about the production time, the source of dyeing material, dyeing process and preservation status were existed in organic dyestuff deriving from cultural relics and artifacts. However, because of the low contents, complex compositions and easily degraded of dyestuff, it is always a challenging task to identify the dyestuff in relics analyzing field. As a finger-print spectrum, Raman spectroscopy owns unique superiorities in dyestuff identification. Thus, the principle, characteristic, limitation, progress and development direction of micro-Raman spectroscopy (MRS/µ-Raman), near infrared reflection and Fourier transform Raman spectroscopy (NIR-FT-Raman), surface-enhanced Raman spectroscopy (SERS) and resonance raman spectroscopy (RRS) have been introduced in this paper. Furthermore, the features of Raman spectra of gardenia, curcumin and other natural dyestuffs were classified by MRS technology, and then the fluorescence phenomena of purpurin excitated with different wavelength laser was compared and analyzed. At last, gray green silver colloidal particles were made as the base, then the colorant of madder was identified combining with thin layer chromatography (TLC) separation technology and SERS, the result showed that the surface enhancement effect of silver colloidal particles could significantly reduce fluorescence background of the Raman spectra. It is pointed out that Raman spectroscopy is a rapid and convenient molecular structure qualitative methodology, which has broad application prospect in dyestuff analysis of cultural relics and artifacts. We propose that the combination of multi-Raman spectroscopy, separation technology and long distance transmission technology are the development trends of Raman spectroscopy.

Cosmic selection rule for the glueball dark matter relic density

DOE PAGES

Soni, Amarjit; Xiao, Huangyu; Zhang, Yue

2017-10-16

Here, we point out a unique mechanism to produce the relic abundance for the glueball dark matter from a gauged SU(N) d hidden sector which is bridged to the standard model sector through heavy vectorlike quarks colored under gauge interactions from both sides. A necessary ingredient of our assumption is that the vectorlike quarks, produced either thermally or nonthermally, are abundant enough to dominate the universe for some time in the early universe. They later undergo dark color confinement and form unstable vectorlike-quarkonium states which annihilate decay and reheat the visible and dark sectors. The ratio of entropy dumped intomore » two sectors and the final energy budget in the dark glueballs is only determined by low energy parameters, including the intrinsic scale of the dark SU(N) d, Λ d, and number of dark colors, N d, but depend weakly on parameters in the ultraviolet such as the vectorlike quark mass or the initial condition. We call this a cosmic selection rule for the glueball dark matter relic density.« less

Gluino coannihilation revisited

DOE PAGES

Ellis, John; Luo, Feng; Olive, Keith A.

2015-09-21

In this study, some variants of the MSSM feature a strip in parameter space where the lightest neutralino χ is identified as the lightest supersymmetric particle (LSP), the gluino g ~ is the next-to-lightest supersymmetric particle (NLSP) and is nearly degenerate with χ, and the relic cold dark matter density is brought into the range allowed by astrophysics and cosmology by coannihilation with the gluino NLSP. We calculate the relic density along this gluino coannihilation strip in the MSSM, including the effects of gluino-gluino bound states and initial-state Sommerfeld enhancement, and taking into account the decoupling of the gluino andmore » LSP densities that occurs for large values of the squark mass m q ~. We find that bound-state effects can increase the maximum m χ for which the relic cold dark matter density lies within the range favoured by astrophysics and cosmology by as much as ~50% if m q ~/m g ~=1.1 , and that the LSP may weigh up to ~8 TeV for a wide range of m q ~/m g ~≲100 .« less

Green glass vitrophyre 78526 - An impact of very low-Ti mare basalt composition

NASA Technical Reports Server (NTRS)

Warner, R. D.; Taylor, G. J.; Kiel, K.; Planner, H. H.; Nehru, C. E.; Ma, M.-S.; Schmitt, R. A.

1978-01-01

Rake sample 78526 is an 8.77 g rock consisting primarily of vitrophyric pale green glass with subordinate mineral and lithic relics. Petrographic and compositional evidence leads to the following conclusions: (1) the bulk composition represents that of a mixture formed by impact melting of at least two different textural and compositional varieties of VLT mare basalt that are now present in the rock as lithic relics and a poorly defined low-Ti mare basalt component observed in thin section only in the form of isolated mineral relics; (2) the admixed VLT mare basalts had REE abundances lower than those found in other mare basalts (but probably higher than emerald green glass) and REE patterns showing significant enrichment of the heavy relative to light REE's, suggesting that they were derived by comparatively high degrees of partial melting of a clinopyroxene-rich source region; and (3) the impact melt supercooled to produce the vitrophyre, with rather sharply contrasting textural domains present in the vitrophyre resulting from differences in nucleation kinetics and degrees of supercooling in various portions of the sample.

Signal photon flux generated by high-frequency relic gravitational waves

NASA Astrophysics Data System (ADS)

Li, Xin; Wang, Sai; Wen, Hao

2016-08-01

The power spectrum of primordial tensor perturbations increases rapidly in the high frequency region if the spectral index n t > 0. It is shown that the amplitude of relic gravitational waves h t(5 × 109 Hz) varies from 10-36 to 10-25 while n t varies from -6.25 × 10-3 to 0.87. A high frequency gravitational wave detector proposed by F.-Y. Li detects gravitational waves through observing the perturbed photon flux that is generated by interaction between relic gravitational waves and electromagnetic field. It is shown that the perturbative photon flux (5 × 109 Hz) varies from 1.40 × 10-4 s-1 to 2.85 × 107 s-1 while n t varies from -6.25 × 10-3 to 0.87. Correspondingly, the ratio of the transverse perturbative photon flux to the background photon flux varies from 10-28 to 10-16. Supported by National Natural Science Foundation of China (11305181,11322545,11335012) and Open Project Program of State Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of Sciences, China (Y5KF181CJ1)

RELICS: Reionization Lensing Cluster Survey

NASA Astrophysics Data System (ADS)

Coe, Dan A.; RELICS Team

2017-01-01

Hubble and Spitzer imaging programs observing galaxy cluster lenses have delivered some of the highest redshift galaxy candidates to date (z ~ 9 - 11, or 540 - 410 Myr after the Big Bang). These magnified galaxies are intrinsically faint, and thus more representative of the sources believed to be primarily responsible for reionization. Magnified galaxies are also observed brightly enough to be prime targets for detailed follow-up study with current and future observatories, including JWST. Building on the successes of CLASH and the Frontier Fields, we have begun RELICS, the Reionization Lensing Cluster Survey. By observing 41 massive clusters for the first time at infrared wavelengths, RELICS will deliver more of the best and brightest high-redshift candidates to the community in time for the November 2017 JWST GO Cycle 1 call for proposals. I will present our early results. I will also discuss prospects for JWST to follow-up known candidates and discover new galaxies at even higher redshifts (z > 11). The discovery efficiency gains from lensing will be even more pronounced at z > 11 if luminosity function faint end slopes are steeper than alpha ~ -2, as suggested by current models and observational extrapolations.

Cosmic selection rule for the glueball dark matter relic density

DOE Office of Scientific and Technical Information (OSTI.GOV)

Soni, Amarjit; Xiao, Huangyu; Zhang, Yue

Here, we point out a unique mechanism to produce the relic abundance for the glueball dark matter from a gauged SU(N) d hidden sector which is bridged to the standard model sector through heavy vectorlike quarks colored under gauge interactions from both sides. A necessary ingredient of our assumption is that the vectorlike quarks, produced either thermally or nonthermally, are abundant enough to dominate the universe for some time in the early universe. They later undergo dark color confinement and form unstable vectorlike-quarkonium states which annihilate decay and reheat the visible and dark sectors. The ratio of entropy dumped intomore » two sectors and the final energy budget in the dark glueballs is only determined by low energy parameters, including the intrinsic scale of the dark SU(N) d, Λ d, and number of dark colors, N d, but depend weakly on parameters in the ultraviolet such as the vectorlike quark mass or the initial condition. We call this a cosmic selection rule for the glueball dark matter relic density.« less

Detection of a Double Relic in the Torpedo Cluster: SPT-CL J0245-5302

NASA Astrophysics Data System (ADS)

Zheng, Q.; Johnston-Hollitt, M.; Duchesne, S. W.; Li, W. T.

2018-06-01

The Torpedo cluster, SPT-CL J0245-5302 (S0295) is a massive, merging cluster at a redshift of z = 0.300, which exhibits a strikingly similar morphology to the Bullet cluster 1E 0657-55.8 (z = 0.296), including a classic bow shock in the cluster's intra-cluster medium revealed by Chandra X-ray observations. We present Australia Telescope Compact Array data centred at 2.1 GHz and Murchison Widefield Array data at frequencies between 72 MHz and 231 MHz which we use to study the properties of the cluster. We characterise a number of discrete and diffuse radio sources in the cluster, including the detection of two previously unknown radio relics on the cluster periphery. The average spectral index of the diffuse emission between 70 MHz and 3.1 GHz is α =-1.63_{-0.10}^{+0.10} and a radio-derived Mach number for the shock in the west of the cluster is calculated as M = 2.04. The Torpedo cluster is thus a double relic system at moderate redshift.

micrOMEGAs 2.0: A program to calculate the relic density of dark matter in a generic model

NASA Astrophysics Data System (ADS)

Bélanger, G.; Boudjema, F.; Pukhov, A.; Semenov, A.

2007-03-01

micrOMEGAs 2.0 is a code which calculates the relic density of a stable massive particle in an arbitrary model. The underlying assumption is that there is a conservation law like R-parity in supersymmetry which guarantees the stability of the lightest odd particle. The new physics model must be incorporated in the notation of CalcHEP, a package for the automatic generation of squared matrix elements. Once this is done, all annihilation and coannihilation channels are included automatically in any model. Cross-sections at v=0, relevant for indirect detection of dark matter, are also computed automatically. The package includes three sample models: the minimal supersymmetric standard model (MSSM), the MSSM with complex phases and the NMSSM. Extension to other models, including non-supersymmetric models, is described. Program summaryTitle of program:micrOMEGAs2.0 Catalogue identifier:ADQR_v2_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/ADQR_v2_0 Program obtainable from: CPC Program Library, Queen's University of Belfast, N. Ireland Computers for which the program is designed and others on which it has been tested:PC, Alpha, Mac, Sun Operating systems under which the program has been tested:UNIX (Linux, OSF1, SunOS, Darwin, Cygwin) Programming language used:C and Fortran Memory required to execute with typical data:17 MB depending on the number of processes required No. of processors used:1 Has the code been vectorized or parallelized:no No. of lines in distributed program, including test data, etc.:91 778 No. of bytes in distributed program, including test data, etc.:1 306 726 Distribution format:tar.gz External routines/libraries used:no Catalogue identifier of previous version:ADQR_v1_3 Journal reference of previous version:Comput. Phys. Comm. 174 (2006) 577 Does the new version supersede the previous version:yes Nature of physical problem:Calculation of the relic density of the lightest stable particle in a generic new model of particle physics. Method of solution: In numerically solving the evolution equation for the density of dark matter, relativistic formulae for the thermal average are used. All tree-level processes for annihilation and coannihilation of new particles in the model are included. The cross-sections for all processes are calculated exactly with CalcHEP after definition of a model file. Higher-order QCD corrections to Higgs couplings to quark pairs are included. Reasons for the new version:There are many models of new physics that propose a candidate for dark matter besides the much studied minimal supersymmetric standard model. This new version not only incorporates extensions of the MSSM, such as the MSSM with complex phases, or the NMSSM which contains an extra singlet superfield but also gives the possibility for the user to incorporate easily a new model. For this the user only needs to redefine appropriately a new model file. Summary of revisions:Possibility to include in the package any particle physics model with a discrete symmetry that guarantees the stability of the cold dark matter candidate (LOP) and to compute the relic density of CDM. Compute automatically the cross-sections for annihilation of the LOP at small velocities into SM final states and provide the energy spectra for γ,e,p¯,ν final states. For the MSSM with input parameters defined at the GUT scale, the interface with any of the spectrum calculator codes reads an input file in the SUSY Les Houches Accord format (SLHA). Implementation of the MSSM with complex parameters (CPV-MSSM) with an interface to CPsuperH to calculate the spectrum. Routine to calculate the electric dipole moment of the electron in the CPV-MSSM. In the NMSSM, new interface compatible with NMHDECAY2.1. Typical running time:0.2 sec Unusual features of the program:Depending on the parameters of the model, the program generates additional new code, compiles it and loads it dynamically.

Novel Implementations of Wideband Tightly Coupled Dipole Arrays for Wide-Angle Scanning

NASA Astrophysics Data System (ADS)

Yetisir, Ersin

Ultra-wideband (UWB) antennas and arrays are essential for high data rate communications and for addressing spectrum congestion. Tightly coupled dipole arrays (TCDAs) are of particular interest due to their low-profile, bandwidth and scanning range. But existing UWB (>3:1 bandwidth) arrays still suffer from limited scanning, particularly at angles beyond 45° from broadside. Almost all previous wideband TCDAs have employed dielectric layers above the antenna aperture to improve scanning while maintaining impedance bandwidth. But even so, these UWB arrays have been limited to no more than 60° away from broadside. In this work, we propose to replace the dielectric superstrate with frequency selective surfaces (FSS). In effect, the FSS is used to create an effective dielectric layer placed over the antenna array. FSS also enables anisotropic responses and more design freedom than conventional isotropic dielectric substrates. Another important aspect of the FSS is its ease of fabrication and low weight, both critical for mobile platforms (e.g. unmanned air vehicles), especially at lower microwave frequencies. Specifically, it can be fabricated using standard printed circuit technology and integrated on a single board with active radiating elements and feed lines. In addition to the FSS superstrate, a modified version of the stripline-based folded Marchand balun is presented. As usual the balun serves to match the 50Ω coaxial cable to the high input impedance ( 200Ω) at the terminals of array elements. Doing so, earlier Wilkinson power dividers, which degrade efficiency during E-plane scanning, are eliminated. To verify the proposed array concept, 12x12 TCDA prototype was fabricated using the modified balun and the new FSS superstrate layer. The design and experimental data showed an impedance bandwidth of 6.1:1 with VSWR<3.2. The latter VSWR was achieved even when scanning down to +/-60° in the H-plane, +/-70° in the D-plane and +/-75° in the E-plane. All array components, including the FSS, radiating dipoles and the feed lines are placed on the same PCB, vertically oriented over the array ground plane, resulting in a low-cost and light-weight structure. The effects of finite aperture sizes in presence of FSS or dielectric superstrates are also considered. Specifically, we compare the performance of finite TCDAs with FSS or dielectric loading. The performance metric is beam pointing accuracy for moderate array sizes ( 30dBi gain) with various edge element terminations. It is shown that even terminating two unit cells at the array edges can provide effective suppression of edge-born waves and achieve excellent beam accuracy. This is the case when both the FSS elements and radiating dipoles are resistively loaded in the unit-cells along the aperture edges.

Lithium-6: A probe of the early universe

PubMed

Jedamzik

2000-04-10

I consider the synthesis of 6Li due to the decay of relic particles, such as gravitinos or moduli, after the epoch of big bang nucleosynthesis. The synthesized 6Li/H ratio may be compared to 6Li/H in metal-poor stars which, in the absence of stellar depletion of 6Li, yields significantly stronger constraints on relic particle densities than the usual consideration of overproduction of 3He. Production of 6Li during such an era of nonthermal nucleosynthesis may also be regarded as a possible explanation for the relatively high 6Li/H ratios observed in metal-poor halo stars.

RADIO AND DEEP CHANDRA OBSERVATIONS OF THE DISTURBED COOL CORE CLUSTER ABELL 133

DOE Office of Scientific and Technical Information (OSTI.GOV)

Randall, S. W.; Nulsen, P. E. J.; Forman, W. R.

2010-10-10

We present results based on new Chandra and multi-frequency radio observations of the disturbed cool core cluster Abell 133. The diffuse gas has a complex bird-like morphology, with a plume of emission extending from two symmetric wing-like features. The plume is capped with a filamentary radio structure that has been previously classified as a radio relic. X-ray spectral fits in the region of the relic indicate the presence of either high-temperature gas or non-thermal emission, although the measured photon index is flatter than would be expected if the non-thermal emission is from inverse Compton scattering of the cosmic microwave backgroundmore » by the radio-emitting particles. We find evidence for a weak elliptical X-ray surface brightness edge surrounding the core, which we show is consistent with a sloshing cold front. The plume is consistent with having formed due to uplift by a buoyantly rising radio bubble, now seen as the radio relic, and has properties consistent with buoyantly lifted plumes seen in other systems (e.g., M87). Alternatively, the plume may be a gas sloshing spiral viewed edge-on. Results from spectral analysis of the wing-like features are inconsistent with the previous suggestion that the wings formed due to the passage of a weak shock through the cool core. We instead conclude that the wings are due to X-ray cavities formed by displacement of X-ray gas by the radio relic. The central cD galaxy contains two small-scale cold gas clumps that are slightly offset from their optical and UV counterparts, suggestive of a galaxy-galaxy merger event. On larger scales, there is evidence for cluster substructure in both optical observations and the X-ray temperature map. We suggest that the Abell 133 cluster has recently undergone a merger event with an interloping subgroup, initialing gas sloshing in the core. The torus of sloshed gas is seen close to edge-on, leading to the somewhat ragged appearance of the elliptical surface brightness edge. We show that the additional buoyant force from a passing subcluster can have a significant effect on the rise trajectories of buoyant bubbles, although this effect alone cannot fully explain the morphology of Abell 133. The radio observations reveal a large-scale double-lobed structure not previously identified in the literature. We conclude that this structure represents a previously unreported background giant radio galaxy at z = 0.293, the northern lobe of which overlies the radio relic in the core of Abell 133. A rough estimate indicates that the contribution of this background lobe to the total radio emission in the region of the relic is modest (<13%).« less

Transparent superstrate terrestrial solar cell module

NASA Technical Reports Server (NTRS)

1977-01-01

The design, development, fabrication, and testing of the transparent solar cell module were examined. Cell performance and material process characteristics were determined by extensive tests and design modifications were made prior to preproduction fabrication. These tests included three cell submodules and two full size engineering modules. Along with hardware and test activity, engineering documentation was prepared and submitted.

String-inspired supergravity model at one loop

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gaillard, M.K.; Papadopoulos, A.; Pierce, D.M.

1992-03-15

We study a prototype supergravity model from superstrings, with three generations of matter fields in the untwisted sector, nonperturbatively induced supersymmetry breaking and including threshold corrections in conformity with modular invariance. The scale degeneracy of the vacuum is lifted at the one-loop level, allowing a determination of the fundamental parameters of the effective low-energy theory.

Small field axion inflation with sub-Planckian decay constant

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kadota, Kenji; Kobayashi, Tatsuo; Oikawa, Akane

2016-10-10

We study an axion inflation model recently proposed within the framework of type IIB superstring theory, where we pay a particular attention to a sub-Planckian axion decay constant. Our axion potential can lead to the small field inflation with a small tensor-to-scalar ratio, and a typical reheating temperature can be as low as GeV.

Cold dark matter plus not-so-clumpy dark relics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Diamanti, Roberta; Ando, Shin'ichiro; Weniger, Christoph

Various particle physics models suggest that, besides the (nearly) cold dark matter that accounts for current observations, additional but sub-dominant dark relics might exist. These could be warm, hot, or even contribute as dark radiation. We present here a comprehensive study of two-component dark matter scenarios, where the first component is assumed to be cold, and the second is a non-cold thermal relic. Considering the cases where the non-cold dark matter species could be either a fermion or a boson, we derive consistent upper limits on the non-cold dark relic energy density for a very large range of velocity dispersions,more » covering the entire range from dark radiation to cold dark matter. To this end, we employ the latest Planck Cosmic Microwave Background data, the recent BOSS DR11 and other Baryon Acoustic Oscillation measurements, and also constraints on the number of Milky Way satellites, the latter of which provides a measure of the suppression of the matter power spectrum at the smallest scales due to the free-streaming of the non-cold dark matter component. We present the results on the fraction f {sub ncdm} of non-cold dark matter with respect to the total dark matter for different ranges of the non-cold dark matter masses. We find that the 2σ limits for non-cold dark matter particles with masses in the range 1–10 keV are f {sub ncdm}≤0.29 (0.23) for fermions (bosons), and for masses in the 10–100 keV range they are f {sub ncdm}≤0.43 (0.45), respectively.« less

Stochastic gravitational wave background from light cosmic strings

DOE Office of Scientific and Technical Information (OSTI.GOV)

DePies, Matthew R.; Hogan, Craig J.

2007-06-15

Spectra of the stochastic gravitational wave backgrounds from cosmic strings are calculated and compared with present and future experimental limits. Motivated by theoretical expectations of light cosmic strings in superstring cosmology, improvements in experimental sensitivity, and recent demonstrations of large, stable loop formation from a primordial network, this study explores a new range of string parameters with masses lighter than previously investigated. A standard 'one-scale' model for string loop formation is assumed. Background spectra are calculated numerically for dimensionless string tensions G{mu}/c{sup 2} between 10{sup -7} and 10{sup -18}, and initial loop sizes as a fraction of the Hubble radiusmore » {alpha} from 0.1 to 10{sup -6}. The spectra show a low frequency power-law tail, a broad spectral peak due to loops decaying at the present epoch (including frequencies higher than their fundamental mode, and radiation associated with cusps), and a flat (constant energy density) spectrum at high frequencies due to radiation from loops that decayed during the radiation-dominated era. The string spectrum is distinctive and unlike any other known source. The peak of the spectrum for light strings appears at high frequencies, significantly affecting predicted signals. The spectra of the cosmic string backgrounds are compared with current millisecond pulsar limits and Laser Interferometer Space Antenna (LISA) sensitivity curves. For models with large stable loops ({alpha}=0.1), current pulsar-timing limits exclude G{mu}/c{sup 2}>10{sup -9}, a much tighter limit on string tension than achievable with other techniques, and within the range of current models based on brane inflation. LISA may detect a background from strings as light as G{mu}/c{sup 2}{approx_equal}10{sup -16}, corresponding to field theory strings formed at roughly 10{sup 11} GeV.« less

Sensitivity projections for dark matter searches with the Fermi large area telescope

NASA Astrophysics Data System (ADS)

Charles, E.; Sánchez-Conde, M.; Anderson, B.; Caputo, R.; Cuoco, A.; Di Mauro, M.; Drlica-Wagner, A.; Gomez-Vargas, G. A.; Meyer, M.; Tibaldo, L.; Wood, M.; Zaharijas, G.; Zimmer, S.; Ajello, M.; Albert, A.; Baldini, L.; Bechtol, K.; Bloom, E. D.; Ceraudo, F.; Cohen-Tanugi, J.; Digel, S. W.; Gaskins, J.; Gustafsson, M.; Mirabal, N.; Razzano, M.

2016-06-01

The nature of dark matter is a longstanding enigma of physics; it may consist of particles beyond the Standard Model that are still elusive to experiments. Among indirect search techniques, which look for stable products from the annihilation or decay of dark matter particles, or from axions coupling to high-energy photons, observations of the γ-ray sky have come to prominence over the last few years, because of the excellent sensitivity of the Large Area Telescope (LAT) on the Fermi Gamma-ray Space Telescope mission. The LAT energy range from 20 meV to above 300 GeV is particularly well suited for searching for products of the interactions of dark matter particles. In this report we describe methods used to search for evidence of dark matter with the LAT, and review the status of searches performed with up to six years of LAT data. We also discuss the factors that determine the sensitivities of these searches, including the magnitudes of the signals and the relevant backgrounds, considering both statistical and systematic uncertainties. We project the expected sensitivities of each search method for 10 and 15 years of LAT data taking. In particular, we find that the sensitivity of searches targeting dwarf galaxies, which provide the best limits currently, will improve faster than the square root of observing time. Current LAT limits for dwarf galaxies using six years of data reach the thermal relic level for masses up to 120 GeV for the b b ¯ annihilation channel for reasonable dark matter density profiles. With projected discoveries of additional dwarfs, these limits could extend to about 250 GeV. With as much as 15 years of LAT data these searches would be sensitive to dark matter annihilations at the thermal relic cross section for masses to greater than 400 GeV (200 GeV) in the b b ¯ (τ+τ-) annihilation channels.

Sensitivity projections for dark matter dearches with the Fermi large area telescope

DOE PAGES

Charles, E.; M. Sanchez-Conde; Anderson, B.; ...

2016-05-20

The nature of dark matter is a longstanding enigma of physics; it may consist of particles beyond the Standard Model that are still elusive to experiments. Among indirect search techniques, which look for stable products from the annihilation or decay of dark matter particles, or from axions coupling to high-energy photons, observations of themore » $$\\gamma$$-ray sky have come to prominence over the last few years, because of the excellent sensitivity of the Large Area Telescope (LAT) on the Fermi Gamma-ray Space Telescope mission. The LAT energy range from 20 MeV to above 300 GeV is particularly well suited for searching for products of the interactions of dark matter particles. In this report we describe methods used to search for evidence of dark matter with the LAT, and review the status of searches performed with up to six years of LAT data. We also discuss the factors that determine the sensitivities of these searches, including the magnitudes of the signals and the relevant backgrounds, considering both statistical and systematic uncertainties. We project the expected sensitivities of each search method for 10 and 15 years of LAT data taking. In particular, we find that the sensitivity of searches targeting dwarf galaxies, which provide the best limits currently, will improve faster than the square root of observing time. Current LAT limits for dwarf galaxies using six years of data reach the thermal relic level for masses up to 120 GeV for the $$b\\bar{b}$$ annihilation channel for reasonable dark matter density profiles. With projected discoveries of additional dwarfs, these limits could extend to about 250 GeV. With as much as 15 years of LAT data these searches would be sensitive to dark matter annihilations at the thermal relic cross section for masses to greater than 400 GeV (200 GeV) in the $$b\\bar{b}$$ ($$\\tau^+ \\tau^-$$) annihilation channels.« less

Sensitivity projections for dark matter dearches with the Fermi large area telescope

DOE Office of Scientific and Technical Information (OSTI.GOV)

Charles, E.; M. Sanchez-Conde; Anderson, B.

The nature of dark matter is a longstanding enigma of physics; it may consist of particles beyond the Standard Model that are still elusive to experiments. Among indirect search techniques, which look for stable products from the annihilation or decay of dark matter particles, or from axions coupling to high-energy photons, observations of themore » $$\\gamma$$-ray sky have come to prominence over the last few years, because of the excellent sensitivity of the Large Area Telescope (LAT) on the Fermi Gamma-ray Space Telescope mission. The LAT energy range from 20 MeV to above 300 GeV is particularly well suited for searching for products of the interactions of dark matter particles. In this report we describe methods used to search for evidence of dark matter with the LAT, and review the status of searches performed with up to six years of LAT data. We also discuss the factors that determine the sensitivities of these searches, including the magnitudes of the signals and the relevant backgrounds, considering both statistical and systematic uncertainties. We project the expected sensitivities of each search method for 10 and 15 years of LAT data taking. In particular, we find that the sensitivity of searches targeting dwarf galaxies, which provide the best limits currently, will improve faster than the square root of observing time. Current LAT limits for dwarf galaxies using six years of data reach the thermal relic level for masses up to 120 GeV for the $$b\\bar{b}$$ annihilation channel for reasonable dark matter density profiles. With projected discoveries of additional dwarfs, these limits could extend to about 250 GeV. With as much as 15 years of LAT data these searches would be sensitive to dark matter annihilations at the thermal relic cross section for masses to greater than 400 GeV (200 GeV) in the $$b\\bar{b}$$ ($$\\tau^+ \\tau^-$$) annihilation channels.« less

The Role of Electroweak Corrections for the Dark Matter Relic Abundance

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ciafaloni, Paolo; Comelli, Denis; Simone, Andrea De

2013-10-01

We analyze the validity of the theorems concerning the cancellation of the infrared and collinar divergences in the case of dark matter freeze-out in the early universe. In particular, we compute the electroweak logarithmic corrections of infrared origin to the annihilation cross section of a dark matter particle being the neutral component of a SU(2){sub L} multiplet. The inclusion of processes with final state W can modify significantly the cross sections computed with only virtual W exchange. Our results show that the inclusion of infrared logs is necessary for a precise computation of the dark matter relic abundance.

Highlighting our international astronomical heritage: Tasmanian relics of the 1874 transit of Venus

NASA Astrophysics Data System (ADS)

Orchiston, Wayne; Buchanan, Alex; Price, Gary; Sprent, Tony

2015-07-01

Through the presence of two 1874 American transit of Venus stations, Tasmania played a key role in determining a value for the astronomical unit. But what makes these two stations even more important is that to this day they preserve relics associated with these historic observations. In this paper we summarise the surviving evidence found at Barrack Square in Hobart, and then revisit the Campbell Town site and provide a new interpretation of the field evidence preserved there. This is a revision of the problematic interpretation that was presented in Orchiston and Buchanan (2004), and is based upon more recent investigations.

Supergravity inflation free from harmful relics

NASA Astrophysics Data System (ADS)

Greene, Patrick B.; Kadota, Kenji; Murayama, Hitoshi

2003-08-01

We present a realistic supergravity inflation model that is free from the overproduction of potentially dangerous relics in cosmology, namely, moduli and gravitinos, which can lead to inconsistencies with the predictions of baryon asymmetry and nucleosynthesis. The radiative correction turns out to play a crucial role in our analysis, raising the mass of the supersymmetry breaking field to an intermediate scale. We pay particular attention to the nonthermal production of gravitinos using the nonminimal Kähler potential we obtained from loop correction. This nonthermal gravitino production is diminished, however, because of the relatively small scale of the inflaton mass and the small amplitudes of the hidden sector fields.

Codecaying Dark Matter.

PubMed

Dror, Jeff Asaf; Kuflik, Eric; Ng, Wee Hao

2016-11-18

We propose a new mechanism for thermal dark matter freeze-out, called codecaying dark matter. Multicomponent dark sectors with degenerate particles and out-of-equilibrium decays can codecay to obtain the observed relic density. The dark matter density is exponentially depleted through the decay of nearly degenerate particles rather than from Boltzmann suppression. The relic abundance is set by the dark matter annihilation cross section, which is predicted to be boosted, and the decay rate of the dark sector particles. The mechanism is viable in a broad range of dark matter parameter space, with a robust prediction of an enhanced indirect detection signal. Finally, we present a simple model that realizes codecaying dark matter.

Is pulsar timing a hopeful tool for detection of relic gravitational waves by using GW150914 data?

NASA Astrophysics Data System (ADS)

Ghayour, Basem

2018-04-01

The inflation stage has a behaviour as power law expansion like S(η )∝ η ^{1+β } where β constrained on the 1+β <0. If the inflation were preceded by a radiation era, then there would be thermal spectrum of relic gravitational waves at the time of inflation. Based on this idea we find new upper bound on β by comparison the thermal spectrum with strain sensitivity of single pulsar timing. Also we show that sensitivity curve of single pulsar timing may be hopeful tool for detection of the spectrum in usual and thermal case by using the GW150914 data.

The 'relics of Joan of Arc': a forensic multidisciplinary analysis.

PubMed

Charlier, P; Poupon, J; Eb, A; De Mazancourt, P; Gilbert, T; Huynh-Charlier, I; Loublier, Y; Verhille, A M; Moulheirat, C; Patou-Mathis, M; Robbiola, L; Montagut, R; Masson, F; Etcheberry, A; Brun, L; Willerslev, E; de la Grandmaison, G Lorin; Durigon, M

2010-01-30

Archaeological remains can provide concrete cases, making it possible to develop, refine or validate medico-legal techniques. In the case of the so-called 'Joan of Arc's relics' (a group of bone and archaeological remains known as the 'Bottle of Chinon'), 14 specialists analysed the samples such as a cadaver X of carbonised aspect: forensic anthropologist, medical examiners, pathologists, geneticists, radiologist, biochemists, palynologists, zoologist and archaeologist. Materials, methods and results of this study are presented here. This study aims to offer an exploitable methodology for the modern medico-legal cases of small quantities of human bones of carbonised aspect. 2009 Elsevier Ireland Ltd. All rights reserved.

VizieR Online Data Catalog: Galaxy clusters: radio halos, relics and parameters (Yuan+, 2015)

NASA Astrophysics Data System (ADS)

Yuan, Z. S.; Han, J. L.; Wen, Z. L.

2017-10-01

A large number of radio halos, relics, and mini-halos have been discovered and measured in recent decades through observations with VLA (e.g., Giovannini & Feretti 2000NewA....5..335G; van Weeren et al. 2011A&A...533A..35V), GMRT (e.g., Venturi et al. 2007A&A...463..937V; Kale et al. 2015A&A...579A..92K), WSRT (e.g., van Weeren et al. 2010Sci...330..347V; Trasatti et al. 2015A&A...575A..45T), and also ATCA (e.g., Shimwell et al. 2014MNRAS.440.2901S, 2015MNRAS.449.1486S). We have checked the radio images of radio halos, relics, and mini-halos in the literature and collected in Table 1 the radio flux Sν at frequencies within a few per cent around 1.4 GHz, 610 MHz, and 325 MHz; we have interpolated the flux at an intermediate frequency if measurements are available at higher and lower frequencies. To establish reliable scaling relations, we include only the very firm detection of diffuse radio emission in galaxy clusters, and omit questionable detections or flux estimates due to problematic point-source subtraction. (3 data files).

Dark Matter in B – L supersymmetric Standard Model with inverse seesaw

DOE Office of Scientific and Technical Information (OSTI.GOV)

Abdallah, W.; Khalil, S., E-mail: awaleed@sci.cu.edu.eg, E-mail: s.khalil@zewailcity.edu.eg

We show that the B – L Supersymmetric Standard Model with Inverse Seesaw (BLSSMIS) provides new Dark Matter (DM) candidates (lightest right-handed sneutrino and lightest B – L neutralino) with mass of order few hundreds GeV, while most of other SUSY spectrum can be quite heavy, consistently with the current Large Hadron Collider (LHC) constraints. We emphasize that the thermal relic abundance and direct detection experiments via relic neutralino scattering with nuclei impose stringent constraints on the B – L neutralinos. These constraints can be satisfied by few points in the parameter space where the B – L lightest neutralinomore » is higgsino-like, which cannot explain the observed Galactic Center (GC) gamma-ray excess measured by Fermi-LAT. The lightest right-handed sneutrino DM is analysed. We show that for a wide region of parameter space the lightest right-handed sneutrino, with mass between 80 GeV and 1.2 TeV, can satisfy the limits of the relic abundance and the scattering cross section with nuclei. We also show that the lightest right-handed sneutrino with mass O(100) GeV can account for the observed GC gamma-ray results.« less

BBN with electron-sterile neutrino oscillations — the finest leptometer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kirilova, Daniela, E-mail: dani@astro.bas.bg

2012-06-01

A relic lepton asymmetry orders of magnitude bigger than the baryon one may hide in the relic neutrino background. No direct theoretical or experimental limitations on its magnitude and sign are known. Only indirect cosmological constraints exist ranging from |L| < 0.01 to L < 10. Here we discuss a Big Bang Nucleosynthesis (BBN) model with late electron-sterile neutrino oscillations. The influence of L on neutrino oscillations and on nucleons freezing in the pre-BBN epoch is numerically analyzed in the full range of the oscillation parameters of the model and for |L| ≥ 10{sup −10}. The asymmetry-oscillations interplay is studiedmore » in detail and the behavior of L for different oscillation parameters is found. L effect on the primordially produced {sup 4}He is precisely studied. It is shown that this BBN model is a fine leptometer, capable of feeling extremely small relic lepton asymmetry — |L| > 10{sup −8}. The case of oscillations generated asymmetry by late electron-sterile oscillations and its effect on the primordial {sup 4}He is also briefly discussed. The instability region of the asymmetry growth is obtained.« less

Numerical Modeling of Exploitation Relics and Faults Influence on Rock Mass Deformations

NASA Astrophysics Data System (ADS)

Wesołowski, Marek

2016-12-01

This article presents numerical modeling results of fault planes and exploitation relics influenced by the size and distribution of rock mass and surface area deformations. Numerical calculations were performed using the finite difference program FLAC. To assess the changes taking place in a rock mass, an anisotropic elasto-plastic ubiquitous joint model was used, into which the Coulomb-Mohr strength (plasticity) condition was implemented. The article takes as an example the actual exploitation of the longwall 225 area in the seam 502wg of the "Pokój" coal mine. Computer simulations have shown that it is possible to determine the influence of fault planes and exploitation relics on the size and distribution of rock mass and its surface deformation. The main factor causing additional deformations of the area surface are the abandoned workings in the seam 502wd. These abandoned workings are the activation factor that caused additional subsidences and also, due to the significant dip, they are a layer on which the rock mass slides down in the direction of the extracted space. These factors are not taken into account by the geometrical and integral theories.

Probing the Curious Case of a Galaxy Cluster Merger in Abell 115 with High-fidelity Chandra X-Ray Temperature and Radio Maps

NASA Astrophysics Data System (ADS)

Hallman, Eric J.; Alden, Brian; Rapetti, David; Datta, Abhirup; Burns, Jack O.

2018-05-01

We present results from an X-ray and radio study of the merging galaxy cluster Abell 115. We use the full set of five Chandra observations taken of A115 to date (360 ks total integration) to construct high-fidelity temperature and surface brightness maps. We also examine radio data from the Very Large Array at 1.5 GHz and the Giant Metrewave Radio Telescope at 0.6 GHz. We propose that the high X-ray spectral temperature between the subclusters results from the interaction of the bow shocks driven into the intracluster medium by the motion of the subclusters relative to one another. We have identified morphologically similar scenarios in Enzo numerical N-body/hydrodynamic simulations of galaxy clusters in a cosmological context. In addition, the giant radio relic feature in A115, with an arc-like structure and a relatively flat spectral index, is likely consistent with other shock-associated giant radio relics seen in other massive galaxy clusters. We suggest a dynamical scenario that is consistent with the structure of the X-ray gas, the hot region between the clusters, and the radio relic feature.

The case for electron re-acceleration at galaxy cluster shocks

NASA Astrophysics Data System (ADS)

van Weeren, Reinout J.; Andrade-Santos, Felipe; Dawson, William A.; Golovich, Nathan; Lal, Dharam V.; Kang, Hyesung; Ryu, Dongsu; Brìggen, Marcus; Ogrean, Georgiana A.; Forman, William R.; Jones, Christine; Placco, Vinicius M.; Santucci, Rafael M.; Wittman, David; Jee, M. James; Kraft, Ralph P.; Sobral, David; Stroe, Andra; Fogarty, Kevin

2017-01-01

On the largest scales, the Universe consists of voids and filaments making up the cosmic web. Galaxy clusters are located at the knots in this web, at the intersection of filaments. Clusters grow through accretion from these large-scale filaments and by mergers with other clusters and groups. In a growing number of galaxy clusters, elongated Mpc-sized radio sources have been found1,2 . Also known as radio relics, these regions of diffuse radio emission are thought to trace relativistic electrons in the intracluster plasma accelerated by low-Mach-number shocks generated by cluster-cluster merger events 3 . A long-standing problem is how low-Mach-number shocks can accelerate electrons so efficiently to explain the observed radio relics. Here, we report the discovery of a direct connection between a radio relic and a radio galaxy in the merging galaxy cluster Abell 3411-3412 by combining radio, X-ray and optical observations. This discovery indicates that fossil relativistic electrons from active galactic nuclei are re-accelerated at cluster shocks. It also implies that radio galaxies play an important role in governing the non-thermal component of the intracluster medium in merging clusters.

PeV IceCube signals and Dark Matter relic abundance in modified cosmologies

NASA Astrophysics Data System (ADS)

Lambiase, G.; Mohanty, S.; Stabile, An.

2018-04-01

The discovery by the IceCube experiment of a high-energy astrophysical neutrino flux with energies of the order of PeV, has opened new scenarios in astroparticles physics. A possibility to explain this phenomenon is to consider the minimal models of Dark Matter (DM) decay, the 4-dimensional operator ˜ y_{α χ }\\overline{{L_{L_{α }}}} H χ , which is also able to generate the correct abundance of DM in the Universe. Assuming that the cosmological background evolves according to the standard cosmological model, it follows that the rate of DM decay Γ _χ ˜ |y_{α χ }|^2 needed to get the correct DM relic abundance (Γ _χ ˜ 10^{-58}) differs by many orders of magnitude with respect that one needed to explain the IceCube data (Γ _χ ˜ 10^{-25}), making the four-dimensional operator unsuitable. In this paper we show that assuming that the early Universe evolution is governed by a modified cosmology, the discrepancy between the two the DM decay rates can be reconciled, and both the IceCube neutrino rate and relic density can be explained in a minimal model.

Nonuniform multiview color texture mapping of image sequence and three-dimensional model for faded cultural relics with sift feature points

NASA Astrophysics Data System (ADS)

Li, Na; Gong, Xingyu; Li, Hongan; Jia, Pengtao

2018-01-01

For faded relics, such as Terracotta Army, the 2D-3D registration between an optical camera and point cloud model is an important part for color texture reconstruction and further applications. This paper proposes a nonuniform multiview color texture mapping for the image sequence and the three-dimensional (3D) model of point cloud collected by Handyscan3D. We first introduce nonuniform multiview calibration, including the explanation of its algorithm principle and the analysis of its advantages. We then establish transformation equations based on sift feature points for the multiview image sequence. At the same time, the selection of nonuniform multiview sift feature points is introduced in detail. Finally, the solving process of the collinear equations based on multiview perspective projection is given with three steps and the flowchart. In the experiment, this method is applied to the color reconstruction of the kneeling figurine, Tangsancai lady, and general figurine. These results demonstrate that the proposed method provides an effective support for the color reconstruction of the faded cultural relics and be able to improve the accuracy of 2D-3D registration between the image sequence and the point cloud model.

The case for electron re-acceleration at galaxy cluster shocks

DOE Office of Scientific and Technical Information (OSTI.GOV)

van Weeren, Reinout J.; Andrade-Santos, Felipe; Dawson, William A.

On the largest scales, the Universe consists of voids and filaments making up the cosmic web. Galaxy clusters are located at the knots in this web, at the intersection of filaments. Clusters grow through accretion from these large-scale filaments and by mergers with other clusters and groups. In a growing number of galaxy clusters, elongated Mpc-sized radio sources have been found. Also known as radio relics, these regions of diffuse radio emission are thought to trace relativistic electrons in the intracluster plasma accelerated by low-Mach-number shocks generated by cluster–cluster merger events. A long-standing problem is how low-Mach-number shocks can acceleratemore » electrons so efficiently to explain the observed radio relics. Here, we report the discovery of a direct connection between a radio relic and a radio galaxy in the merging galaxy cluster Abell 3411–3412 by combining radio, X-ray and optical observations. This discovery indicates that fossil relativistic electrons from active galactic nuclei are re-accelerated at cluster shocks. Lastly, it also implies that radio galaxies play an important role in governing the non-thermal component of the intracluster medium in merging clusters.« less

The case for electron re-acceleration at galaxy cluster shocks

DOE PAGES

van Weeren, Reinout J.; Andrade-Santos, Felipe; Dawson, William A.; ...

2017-01-04

On the largest scales, the Universe consists of voids and filaments making up the cosmic web. Galaxy clusters are located at the knots in this web, at the intersection of filaments. Clusters grow through accretion from these large-scale filaments and by mergers with other clusters and groups. In a growing number of galaxy clusters, elongated Mpc-sized radio sources have been found. Also known as radio relics, these regions of diffuse radio emission are thought to trace relativistic electrons in the intracluster plasma accelerated by low-Mach-number shocks generated by cluster–cluster merger events. A long-standing problem is how low-Mach-number shocks can acceleratemore » electrons so efficiently to explain the observed radio relics. Here, we report the discovery of a direct connection between a radio relic and a radio galaxy in the merging galaxy cluster Abell 3411–3412 by combining radio, X-ray and optical observations. This discovery indicates that fossil relativistic electrons from active galactic nuclei are re-accelerated at cluster shocks. Lastly, it also implies that radio galaxies play an important role in governing the non-thermal component of the intracluster medium in merging clusters.« less

Higgs funnel region of supersymmetric dark matter for small tan⁡β and renormalization group effects on pseudoscalar Higgs boson with scalar mass nonuniversality

NASA Astrophysics Data System (ADS)

Chattopadhyay, Utpal; Das, Debottam

2009-02-01

A nonuniversal scalar mass supergravity type of model is explored where the first two generations of scalars and the third generation of sleptons may be very massive. The lighter or vanishing third generation of squarks as well as Higgs scalars at the unification scale cause the radiative electroweak symmetry breaking constraint to be less prohibitive. Thus, both flavor-changing neutral-current/CP-violation problems as well as the naturalness problem are within control. We identify a large slepton mass effect in the renormalization group equations of mHD2 (for the down type of Higgs) that may turn the latter negative at the electroweak scale even for a small tan⁡β. A hyperbolic branch/focus pointlike effect is found for mA2 that may result in very light Higgs spectra. The lightest stable particle is dominantly a b-ino that pair annihilates via Higgs exchange, giving rise to a Wilkinson Microwave Anisotropy Probe satisfied relic density region for all tan⁡β. Detection prospects of such lightest stable particles in the upcoming dark matter experiments both of direct and indirect types (photon flux) are interesting. The Higgs bosons and the third generation of squarks are light in this scenario and these may be easily probed besides charginos and neutralinos in the early runs of the Large Hadron Collider.

Simplified models of dark matter with a long-lived co-annihilation partner

NASA Astrophysics Data System (ADS)

Khoze, Valentin V.; Plascencia, Alexis D.; Sakurai, Kazuki

2017-06-01

We introduce a new set of simplified models to address the effects of 3-point interactions between the dark matter particle, its dark co-annihilation partner, and the Standard Model degree of freedom, which we take to be the tau lepton. The contributions from dark matter co-annihilation channels are highly relevant for a determination of the correct relic abundance. We investigate these effects as well as the discovery potential for dark matter co-annihilation partners at the LHC. A small mass splitting between the dark matter and its partner is preferred by the co-annihilation mechanism and suggests that the co-annihilation partners may be long-lived (stable or meta-stable) at collider scales. It is argued that such long-lived electrically charged particles can be looked for at the LHC in searches of anomalous charged tracks. This approach and the underlying models provide an alternative/complementarity to the mono-jet and multi-jet based dark matter searches widely used in the context of simplified models with s-channel mediators. We consider four types of simplified models with different particle spins and coupling structures. Some of these models are manifestly gauge invariant and renormalizable, others would ultimately require a UV completion. These can be realised in terms of supersymmetric models in the neutralino-stau co-annihilation regime, as well as models with extra dimensions or composite models.

Solar-Array Substrate From Glass-Reinforced Concrete

NASA Technical Reports Server (NTRS)

Eirls, J. L.

1985-01-01

Design elminiates glass superstrate and associated metal framing. Panel has two trapezoidal stiffening ribs for structural support. Strategic placement of ribs with embedded support tubes (standard PVC tubing) minimizes bending moments and resulting stresses produced by installation and windloads. Glass-reinforced concrete panel has smooth flat surface suitable for solar substrate and includes structural bracing for rigidity and design adaptable to mass production.

Superspace geometrical realization of the N-extended super Virasoro algebra and its dual

NASA Astrophysics Data System (ADS)

Curto, C.; Gates, S. J., Jr.; Rodgers, V. G. J.

2000-05-01

We derive properties of N-extended /GR super Virasoro algebras. These include adding central extensions, identification of all primary fields and the action of the adjoint representation on its dual. The final result suggest identification with the spectrum of fields in supergravity theories and superstring/M-theory constructed from NSR N-extended supersymmetric /GR Virasoro algebras.

Branes and the Kraft-Procesi transition: classical case

NASA Astrophysics Data System (ADS)

Cabrera, Santiago; Hanany, Amihay

2018-04-01

Moduli spaces of a large set of 3 d N=4 effective gauge theories are known to be closures of nilpotent orbits. This set of theories has recently acquired a special status, due to Namikawa's theorem. As a consequence of this theorem, closures of nilpotent orbits are the simplest non-trivial moduli spaces that can be found in three dimensional theories with eight supercharges. In the early 80's mathematicians Hanspeter Kraft and Claudio Procesi characterized an inclusion relation between nilpotent orbit closures of the same classical Lie algebra. We recently [1] showed a physical realization of their work in terms of the motion of D3-branes on the Type IIB superstring embedding of the effective gauge theories. This analysis is restricted to A-type Lie algebras. The present note expands our previous discussion to the remaining classical cases: orthogonal and symplectic algebras. In order to do so we introduce O3-planes in the superstring description. We also find a brane realization for the mathematical map between two partitions of the same integer number known as collapse. Another result is that basic Kraft-Procesi transitions turn out to be described by the moduli space of orthosymplectic quivers with varying boundary conditions.

A New Metasurface Superstrate Structure for Antenna Performance Enhancement.

PubMed

Islam, Mohammad Tariqul; Ullah, Mohammad Habib; Singh, Mandeep Jit; Faruque, Mohammad Rashed Iqbal

2013-07-31

A new metasurface superstrate structure (MSS)-loaded dual band microstrip line-fed small patch antenna is presented in this paper. The proposed antenna was designed on a ceramic-filled bioplastic sandwich substrate with a high dielectric constant. The proposed 7 × 6 element, square-shaped, single-sided MSS significantly improved the bandwidth and gain of the proposed antenna. The proposed MSS incorporated a slotted patch antenna that effectively increased the measured operating bandwidth from 13.3% to 18.8% and from 14.8% to 23.2% in the lower and upper bands, respectively. Moreover, the average gain of the proposed MSS-based antenna was enhanced from 2.12 dBi to 3.02 dBi in the lower band and from 4.10 dBi to 5.28 dBi in the upper band compared to the patch antenna alone. In addition to the bandwidth and gain improvements, more directive radiation characteristics were also observed from the MSS antenna compared to the patch itself. The effects of the MSS elements and the ground plane length on the reflection coefficient of the antenna were analyzed and optimized. The overall performance makes the proposed antenna appropriate for RFID and WLAN applications.

On the worldsheet theory of the type IIA {text{Ad}}{{text{S}}_4} × mathbb{C}{mathbb{P}_3} superstring

NASA Astrophysics Data System (ADS)

Sundin, Per

2010-04-01

We perform a detailed study of the type IIA superstring in {text{Ad}}{{text{S}}_4} × mathbb{C}{mathbb{P}_3} . After introducing suitable bosonic light-cone and fermionic kappa worldsheet gauges we derive the pure boson and fermion SU(2|2)×U(1) covariant light-cone Hamiltonian up to quartic order in fields. As a first application of our derivation we calculate energy shifts for string configurations in a closed fermionic subsector and successfully match these with a set of light-cone Bethe equations. We then turn to investigate the mismatch between the degrees of freedom of scattering states and oscillatory string modes. Since only light string modes appear as fundamental Bethe roots in the scattering theory, the physical role of the remaining 4 F + 4 B massive oscillators is rather unclear. By continuing a line of research initiated by Zarembo, we shed light on this question by calculating quantum corrections for the propagators of the bosonic massive fields. We show that, once loop corrections are incorporated, the massive coordinates dissolve in a continuum state of two light particles.

A New Metasurface Superstrate Structure for Antenna Performance Enhancement

PubMed Central

Islam, Mohammad Tariqul; Ullah, Mohammad Habib; Singh, Mandeep Jit; Faruque, Mohammad Rashed Iqbal

2013-01-01

A new metasurface superstrate structure (MSS)-loaded dual band microstrip line-fed small patch antenna is presented in this paper. The proposed antenna was designed on a ceramic-filled bioplastic sandwich substrate with a high dielectric constant. The proposed 7 × 6 element, square-shaped, single-sided MSS significantly improved the bandwidth and gain of the proposed antenna. The proposed MSS incorporated a slotted patch antenna that effectively increased the measured operating bandwidth from 13.3% to 18.8% and from 14.8% to 23.2% in the lower and upper bands, respectively. Moreover, the average gain of the proposed MSS-based antenna was enhanced from 2.12 dBi to 3.02 dBi in the lower band and from 4.10 dBi to 5.28 dBi in the upper band compared to the patch antenna alone. In addition to the bandwidth and gain improvements, more directive radiation characteristics were also observed from the MSS antenna compared to the patch itself. The effects of the MSS elements and the ground plane length on the reflection coefficient of the antenna were analyzed and optimized. The overall performance makes the proposed antenna appropriate for RFID and WLAN applications. PMID:28811432

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pern, F.J.; Glick, S.H.; Czanderna, A.W.

Results from extensive studies of the commercial ethylene vinyl acetate (EVA) formulations show that the UV absorber and curing-generated UV-excitable, {alpha},{beta}-unsaturated carbonyl chromophores facilitate the EVA discoloration, which is further enhanced by curing-generated acetic acid and probably residual peroxide curing agent also. Formation and concentration of the UV-excitable chromophores are substantially promoted by the antioxidant, Naugard P. The discoloration rate is greater under higher UV light intensity and temperatures. Heating in the dark at elevated temperatures (e.g., 85&hthinsp;{degree}C) in the air for {approximately}200 days only results in light yellowing. The discoloration reactions compete with photobleaching reactions, which destroy curing-generated chromophoresmore » and result in non-discoloring of EVA. By using better performance stabilizers to minimize the curing-generated UV-excitable chromophores, a new fast curing agent, and no UV absorber, the NREL-developed EVA formulations show a superior photothermal stability against browning to the commercial counterparts. Alternatively, the discoloration rate of the commercial EVA pottants can be considerably reduced by using UV-filtering glass superstrates that largely inhibit the UV-induced photooxidation reactions, or completely eliminated by using air-permeable polymer superstrate films that enable photobleaching reactions. {copyright} {ital 1999 American Institute of Physics.}« less

Supersymmetric solutions of the cosmological, gauged, ℂ magic model

NASA Astrophysics Data System (ADS)

Chimento, Samuele; Ortín, Tomás; Ruipérez, Alejandro

2018-05-01

We construct supersymmetric solutions of theories of gauged N = 1 , d = 5 supergravity coupled to vector multiplets with a U(1)R Abelian (Fayet-Iliopoulos) gauging and an independent SU(2) gauging associated to an SU(2) isometry group of the Real Special scalar manifold. These theories provide minimal supersymmetrizations of 5-dimensional SU(2) Einstein-Yang-Mills theories with negative cosmological constant. We consider a minimal model with these gauge groups and the "magic model" based on the Jordan algebra J 3 ℂ with gauge group SU(3) × U(1)R, which is a consistent truncation of maximal SO(6)-gauged supergravity in d = 5 and whose solutions can be embedded in Type IIB Superstring Theory. We find several solutions containing selfdual SU(2) instantons, some of which asymptote to AdS5 and some of which are very small, supersymmetric, deformations of AdS5. We also show how some of those solutions can be embedded in Romans' SU(2) × U(1)-gauged half-maximal supergravity, which was obtained by Lu, Pope and Tran by compactification of the Type IIB Superstring effective action. This provides another way of uplifting those solutions to 10 dimensions.

Perturbations and moduli space dynamics of tachyon kinks

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hindmarsh, Mark; Li Huiquan

2008-03-15

The dynamic process of unstable D-branes decaying into stable ones with one dimension lower can be described by a tachyon field with a Dirac-Born-Infeld effective action. In this paper we investigate the fluctuation modes of the tachyon field around a two-parameter family of static solutions representing an array of brane-antibrane pairs. Besides a pair of zero modes associated with the parameters of the solution, and instabilities associated with annihilation of the brane-antibrane pairs, we find states corresponding to excitations of the tachyon field around the brane and in the bulk. In the limit that the brane thickness tends to zero,more » the support of the eigenmodes is limited to the brane, consistent with the idea that propagating tachyon modes drop out of the spectrum as the tachyon field approaches its ground state. The zero modes, and other low-lying excited states, show a fourfold degeneracy in this limit, which can be identified with some of the massless superstring modes in the brane-antibrane system. Finally, we also discuss the slow motion of the solution corresponding to the decay process in the moduli space, finding a trajectory which oscillates periodically between the unstable D-brane and the brane-antibrane pairs of one dimension lower.« less

Tectono-metamorphic evolution of meta-ophiolitic units along Susa Valley (Italian Western Alps): new suggestions for the exhumation processes

NASA Astrophysics Data System (ADS)

Ghignone, Stefano; Borghi, Alessandro; Balestro, Gianni; Gattiglio, Marco

2017-04-01

In the inner Western Alps, meta-ophiolite units (i.e., the Piemonte Zone) show different stages of the tectono-metamorphic evolution, since the early phases of subduction to the latest exhumation steps. Tectono-metamorphic data collected through the meta-ophiolite units of the Piemonte Zone along the middle Susa Valley allowed to infer new ideas about the exhumation processes that developed in the (U)HP units. In this area, Zermatt-Saas-like meta-ophiolite unit (i.e., the eclogite-facies Internal Piemonte Zone, IPZ) are tectonically overlain by Combin-like ones (i.e., the blueschist-facies External Piemonte Zone, EPZ), through a thick shear zone (i.e., the Susa Shear Zone, SSZ). Metamorphic history was achieved by analyzing basic rocks (metabasalt and Fe-Ti metagabbro) and sedimentary rocks derived from reworking basic rocks in oceanic environment (basic sandstones and conglomerates, and ophiolitic breccia). Different P-T paths were inferred for IPZ and EPZ, according with mineral assemblages and realizations of pseudosections. In the IPZ, four tectono-metamorphic events, developed under variables metamorphic conditions, were recognized. The first (peak-P) event shows (U)HP conditions, defined by the occurrence of relic mineral assemblage (Grt I+ Omp I + Rt). The paragenesis is completed by Zo + Pg pseudomorphs, implying that Lws-eclogite facies were reached. The discovery in Grt (and Rt) relics inclusions of black euhedral pseudomorphs of disordered graphite, suggesting to be derived from original microdiamonds, agree with other petrologic constrains. The second event, marked by the Grt II + Omp II + Ph + Gln + Zo assemblage, developed under epidote-eclogite facies conditions. Following a retrograde and decompressional trajectory, the IPZ was then re-equilibrated under greenschist-facies conditions and a new assemblage (Ab + Chl + Mu + Czo + Ttn + Act) overprinted HP paragenesis. The last event is marked by a weak heating, with crystallization of Bt + Ep + Olig + Hbl (Prg) + Ms. The EPZ shows a different metamorphic evolution, where only two events were recognized. The first event developed under blueschist-facies conditions, with relics of mineral assemblages consisting of Gln + Rt + Ph. Then, a retrograde trajectory re-equilibrated EPZ under greenschist-facies conditions and a new stable mineral assemblage (Ab + Chl + Mu + Ttn + Act + Czo) grew. The inferred P-T path suggests, for the IPZ, a first isothermal exhumation stage, likely driven by buoyancy forces from the base of the orogenic wedge. In the EPZ, HP peak occurs at the same gradient of the second event in the IPZ, suggesting that, during exhumation of the IPZ, the EPZ was still subducted. The strong re-equilibration under greenschist-facies conditions suggests a stage of slow exhumation rate, which can be related to the coupling between IPZ and EPZ.

The weak force and SETH: The search for Extra-Terrestrial Homochirality

NASA Astrophysics Data System (ADS)

MacDermott, Alexandra J.

1996-07-01

We propose that a search for extra-terrestrial life can be approached as a Search for Extra-Terrestrial Homochirality-SETH. Homochirality is probably a pre-condition for life, so a chiral influence may be required to get life started. We explain how the weak force mediated by the Z0 boson gives rise to a small parity-violating energy difference (PVED) between enantiomers, and discuss how the resulting small excess of the more stable enantiomer may be amplified to homochirality. Titan and comets are good places to test for emerging pre-biotic homochirality, while on Mars there may be traces of homochirality as a relic of extinct life. Our calculations of the PVED show that the natural L-amino acids are indeed more stable than their enantiomers, as are several key D-sugars and right-hand helical DNA. Thiosubstituted DNA analogues show particularly large PVEDs. L-quartz is also more stable than D-quartz, and we believe that further crystal counts should be carried out to establish whether reported excesses of L quartz are real. Finding extra-terrestrial molecules of the same hand as on Earth would lend support to the universal chiral influence of the weak force. We describe a novel miniaturized space polarimeter, called the SETH Cigar, which we hope to use to detect optical rotation on other planets. Moving parts are avoided by replacing the normal rotating polarizer by multiple fixed polarizers at different angles as in the eye of the bee. Even if we do not find the same hand as on Earth, finding extra-terrestrial optical rotation would be of enormous importance as it would still be the homochiral signature of life.

Relativistic strings - From soap films to a grand unified theory

NASA Astrophysics Data System (ADS)

Nesterenko, V. V.

1986-11-01

The concept of relativistic strings is considered in connection with the theory of minimal surfaces (e.g., soap films stretched onto closed wire contours). The role of relativistic strings in hadron physics is discussed. Attention is then given to the creation of a grand unified theory on the basis of the superstring concept. Finally, the role of relativistic strings in cosmology is examined.

Opto-electronic properties of P-doped nc-Si–QD/a-SiC:H thin films as foundation layer for all-Si solar cells in superstrate configuration

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kar, Debjit; Das, Debajyoti, E-mail: erdd@iacs.res.in

2016-07-14

With the advent of nc-Si solar cells having improved stability, the efficient growth of nc-Si i-layer of the top cell of an efficient all-Si solar cell in the superstrate configuration prefers nc-Si n-layer as its substrate. Accordingly, a wide band gap and high conducting nc-Si alloy material is a basic requirement at the n-layer. Present investigation deals with the development of phosphorous doped n-type nanocrystalline silicon quantum dots embedded in hydrogenated amorphous silicon carbide (nc-Si–QD/a-SiC:H) hetero-structure films, wherein the optical band gap can be widened by the presence of Si–C bonds in the amorphous matrix and the embedded high densitymore » tiny nc-Si–QDs could provide high electrical conductivity, particularly in P-doped condition. The nc-Si–QDs simultaneously facilitate further widening of the optical band gap by virtue of the associated quantum confinement effect. A complete investigation has been made on the electrical transport phenomena involving charge transfer by tunneling and thermionic emission prevailing in n-type nc-Si–QD/a-SiC:H thin films. Their correlation with different phases of the specific heterostructure has been carried out for detailed understanding of the material, in order to improve its device applicability. The n-type nc-Si–QD/a-SiC:H films exhibit a thermally activated electrical transport above room temperature and multi-phonon hopping (MPH) below room temperature, involving defects in the amorphous phase and the grain-boundary region. The n-type nc-Si–QD/a-SiC:H films grown at ∼300 °C, demonstrating wide optical gap ∼1.86–1.96 eV and corresponding high electrical conductivity ∼4.5 × 10{sup −1}–1.4 × 10{sup −2} S cm{sup −1}, deserve to be an effective foundation layer for the top nc-Si sub-cell of all-Si solar cells in n-i-p structure with superstrate configuration.« less

Superstring Compactification and Low Energy Phenomenology.

NASA Astrophysics Data System (ADS)

Mohapatra, Pramoda Kumar

We have presented some aspects of Superstring compactification from 10 to 4 dimensions and the effect of different types of compactification of the extra 6 dimensions on the low energy physics. We have reviewed the consequences of demanding the extra 6 dimensions to form a manifold as well as an N = 1 Supersymmetry at low energies. While doing this we have also highlighted some of the fundamental phenomenological problems like proton decay and neutrino mass and their possible solutions. The dissertation includes a description of the method of calculation of discrete symmetries and Yukawa couplings between different fermions and mirror fermions in these kinds of manifold compactification. The explicit calculations for one particular case with three fermion generations is presented. The reasons for the necessity of an intermediate scale of symmetry breaking (between Plank scale and the electro-weak scale) are explained and one particular scenerio of such symmetry breaking which preserves Supersymmetry is given. We have studied the effect of E _6 singlets on F-flatness and on the phenomenology. We have also reviewed the idea of compactification in a completely different way, i.e. not on a regular manifold but on a manifold with singularities called an orbifold. We have shown that with the so-called standard embedding, meaning identifying the gauge connection with the spin connection, needed for anomaly cancellation and modular invariance, only one model has a chance of being phenomenologically realistic. We have provided explicit tables of all the relevant quantum numbers of the fermions in the fundamental representation of the gauge group E _6 and showed that there are three possible ways of embedding electric charge in the generators of E _6. We have given the explicit form of the renormalization group equation for sin^2theta_{ rm W} and alpha_ {s} for the most usual chain of breaking E _6 down to SU(3)_ {c}otimes SU(2)_{L}otimes(1) _{Y}. The importance of the evolution of the coupling constant on the compactification is also stressed. We have analysed the successes and the limitations of Superstring theories and have mentioned the new frontiers in compactification.

Opto-electronic properties of P-doped nc-Si-QD/a-SiC:H thin films as foundation layer for all-Si solar cells in superstrate configuration

NASA Astrophysics Data System (ADS)

Kar, Debjit; Das, Debajyoti

2016-07-01

With the advent of nc-Si solar cells having improved stability, the efficient growth of nc-Si i-layer of the top cell of an efficient all-Si solar cell in the superstrate configuration prefers nc-Si n-layer as its substrate. Accordingly, a wide band gap and high conducting nc-Si alloy material is a basic requirement at the n-layer. Present investigation deals with the development of phosphorous doped n-type nanocrystalline silicon quantum dots embedded in hydrogenated amorphous silicon carbide (nc-Si-QD/a-SiC:H) hetero-structure films, wherein the optical band gap can be widened by the presence of Si-C bonds in the amorphous matrix and the embedded high density tiny nc-Si-QDs could provide high electrical conductivity, particularly in P-doped condition. The nc-Si-QDs simultaneously facilitate further widening of the optical band gap by virtue of the associated quantum confinement effect. A complete investigation has been made on the electrical transport phenomena involving charge transfer by tunneling and thermionic emission prevailing in n-type nc-Si-QD/a-SiC:H thin films. Their correlation with different phases of the specific heterostructure has been carried out for detailed understanding of the material, in order to improve its device applicability. The n-type nc-Si-QD/a-SiC:H films exhibit a thermally activated electrical transport above room temperature and multi-phonon hopping (MPH) below room temperature, involving defects in the amorphous phase and the grain-boundary region. The n-type nc-Si-QD/a-SiC:H films grown at ˜300 °C, demonstrating wide optical gap ˜1.86-1.96 eV and corresponding high electrical conductivity ˜4.5 × 10-1-1.4 × 10-2 S cm-1, deserve to be an effective foundation layer for the top nc-Si sub-cell of all-Si solar cells in n-i-p structure with superstrate configuration.

X-ray fluorescence in investigations of cultural relics and archaeological finds.

PubMed

Musílek, Ladislav; Cechák, Tomáš; Trojek, Tomáš

2012-07-01

Some characteristic features of X-ray fluorescence (XRF) analysis make it an ideal method for investigations of cultural relics and archaeological finds. It has therefore become a standard method used in archaeometry. Paintings, frescos, manuscripts, pottery, metalwork, glass, and many other objects are analysed with the aim of recognising their materials, production technologies and origin, and for identifying counterfeits. This paper reviews various techniques used in XRF analyses of works of art, summarises the advantages and limitations of the method, and presents some typical examples of its use. The general review is supplemented by some techniques used and some results achieved at CTU-FNSPE in Prague. Copyright © 2011 Elsevier Ltd. All rights reserved.

Cross Sections, relic abundance, and detection rates for neutralino dark matter

NASA Technical Reports Server (NTRS)

Griest, Kim

1988-01-01

Neutralino annihilation and elastic scattering cross sections are derived which differ in important ways from previous work. These are applied to relic abundance calculations and to direct detection of neutralino dark matter from the galactic halo. Assuming the neutralino to be the lightest supersymmetric particle and that it is less massive than the Z sup 0, we find relic densities of neutralinos greater than 4 percent of critical density for almost all values of the supersymmetric parameters. We constrain the parameter space by using results from PETRA (chargino mass less than 23 GeV) and ASP, and then assuming a critical density of neutralinos, display event rates in a cryogenic detector for a variety of models. A new term implies spin independent elastic scattering even for those majorana particles and inclusion of propagator momenta increases detection rates by 10 to 300 percent for pure photinos. Z sup 0-squark interference leads to very low detection rates for some values of the parameters. The new term in the elastic cross section dominates for heavy, mostly spinless materials and mitigates the negative interference cancellations in light materials; except for the pure photino or pure higgsinos cases where it does not contribute. In general, the rates can be substantially different from the pure photino and pure higgsino special cases usually considered.

ALMA-SZ Detection of a Galaxy Cluster Merger Shock at Half the Age of the Universe

NASA Astrophysics Data System (ADS)

Basu, K.; Sommer, M.; Erler, J.; Eckert, D.; Vazza, F.; Magnelli, B.; Bertoldi, F.; Tozzi, P.

2016-10-01

We present ALMA measurements of a merger shock using the thermal Sunyaev-Zel’dovich (SZ) effect signal, at the location of a radio relic in the famous El Gordo galaxy cluster at z≈ 0.9. Multi-wavelength analysis in combination with the archival Chandra data and a high-resolution radio image provides a consistent picture of the thermal and non-thermal signal variation across the shock front and helps to put robust constraints on the shock Mach number as well as the relic magnetic field. We employ a Bayesian analysis technique for modeling the SZ and X-ray data self-consistently, illustrating respective parameter degeneracies. Combined results indicate a shock with Mach number { M }={2.4}-0.6+1.3, which in turn suggests a high value of the magnetic field (of the order of 4-10 μ {{G}}) to account for the observed relic width at 2 GHz. At roughly half the current age of the universe, this is the highest-redshift direct detection of a cluster shock to date, and one of the first instances of an ALMA-SZ observation in a galaxy cluster. It shows the tremendous potential for future ALMA-SZ observations to detect merger shocks and other cluster substructures out to the highest redshifts.

Strong Lens Models for Massive Galaxy Clusters in the Reionization Lensing Cluster Survey

NASA Astrophysics Data System (ADS)

Cerny, Catherine; Sharon, Keren; Coe, Dan A.; Paterno-Mahler, Rachel; Jones, Christine; Czakon, Nicole G.; Umetsu, Keiichi; Stark, Daniel; Bradley, Larry D.; Trenti, Michele; Johnson, Traci; Bradac, Marusa; Dawson, William; Rodney, Steven A.; Strolger, Louis-Gregory; RELICS Team

2017-01-01

We present strong lensing models for five galaxy clusters from the Planck SZ cluster catalog as a part of the Reionization Lensing Cluster Survey (RELICS), a program that seeks to constrain the galaxy luminosity function past z~9 by conducting a wide field survey of massive galaxy clusters with HST (GO-14096, PI: Coe). The strong gravitational lensing effects of these clusters significantly magnify background galaxies, which enhances our ability to discover the large numbers of high redshift galaxies at z~9-12 needed to create a representative sample. We use strong lensing models for these clusters to study their mass distribution and magnification, which allows us to quantify the lensing effect on the background galaxies. These models can then be utilized in the RELICS survey in order to identify high redshift galaxy candidates that may be lensed by the clusters. The intrinsic properties of these galaxy candidates can be derived by removing the lensing effect as predicted by our models, which will meet the science goals of the RELICS survey. We use HST WFC3 and ACS imaging to create lensing models for the clusters RXC J0142.9+4438, ACO-2537, ACO-2163, RXCJ2211.7-0349, and ACT-CLJ0102-49151.

[The relic in the Panels of São Vicente de Fora].

PubMed

Goyri-O'Neill, João; Camisão-Soares, Artur; Neves Marques, Cláudia

2013-01-01

The Panels of São Vicente de Fora, a polyptych dated from 1470 to 1480, are a work composed of 6 panels, authored by Nuno Gonçalves, a painter of King Afonso V. This work reveals one of the most remarkable collective portraits of European painting, making this polyptych an inexhaustible source of readings and interpretations, fueling a secular controversy. The present work aims analyzing precise an iconographic anatomical image repainted in the 6th panel, or the panel of the Relic. This consists of a central image within a structure shown by a red figure with special reverence. The investigation conducted and justification was based on direct observation and comparative analysis of iconographic data collected in the Museum of Antique Art. The bone pieces were selected at the Museum of Anatomy, Department of Anatomy, Faculty of Medical Sciences, New University of Lisbon, and the comparative analyses performed by two observers, with further analysis of the images obtained in the National Museum of Ancient Art using specific software. After watching these, it was concluded that this representation of a relic in the Panels of São Vicente is an iconic representation of an Occipital bone, fractured at its lower edge, being evident, almost complete, its vertical portion or scale.

Gravitational Waves Propagation through the Stochastic Background of Gravitational Waves

NASA Astrophysics Data System (ADS)

Frajuca, C.; Bortoli, F. S.; Nakamoto, F. Y.; Santos, G. A.

2018-02-01

With the recent claim that gravitational waves were finally detected and with other efforts around the world for GWs detection, its is reasonable to imagine that the relic gravitational wave background could be detected in some time in the future and with such information gather some hints about the origin of the universe. But, it’s also be considered that gravity has self-interaction, with such assumption it’s reasonable to expect that these gravitational wave will interact with the relic or nonrelic GW background by scattering, for example. Such interaction should decrease the distance which such propagating waves could be detected The propagation of gravitational waves (GWs) is analyzed in an asymptotically de Sitter space by the perturbation expansion around Minkowski space using a scalar component. Using the case of de Sitter inflationary phase scenario, the perturbation propagates through a FRW background. The GW, using the actual value for the Hubble scale (Ho), has a damping factor with a very small valor for the size of the observational universe; the stochastic relic GW background is given by a dimensionless function of the frequency. In this work we analyze this same damping including the gravitational wave background due to astrophysical sources such background is 3 orders of magnitude bigger in some frequencies and produces a higher damping factor.

Bent-tailed radio sources in the australia telescope large area survey of the Chandra deep field south

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dehghan, S.; Johnston-Hollitt, M.; Franzen, T. M. O.

2014-11-01

Using the 1.4 GHz Australia Telescope Large Area Survey, supplemented by the 1.4 GHz Very Large Array images, we undertook a search for bent-tailed (BT) radio galaxies in the Chandra Deep Field South. Here we present a catalog of 56 detections, which include 45 BT sources, 4 diffuse low-surface-brightness objects (1 relic, 2 halos, and 1 unclassified object), and a further 7 complex, multi-component sources. We report BT sources with rest-frame powers in the range 10{sup 22} ≤ P {sub 1.4} {sub GHz} ≤ 10{sup 26} W Hz{sup –1}, with redshifts up to 2 and linear extents from tens ofmore » kiloparsecs up to about 1 Mpc. This is the first systematic study of such sources down to such low powers and high redshifts and demonstrates the complementary nature of searches in deep, limited area surveys as compared to shallower, large surveys. Of the sources presented here, one is the most distant BT source yet detected at a redshift of 2.1688. Two of the sources are found to be associated with known clusters: a wide-angle tail source in A3141 and a putative radio relic which appears at the infall region between the galaxy group MZ 00108 and the galaxy cluster AMPCC 40. Further observations are required to confirm the relic detection, which, if successful, would demonstrate this to be the least powerful relic yet seen with P {sub 1.4} {sub GHz} = 9 × 10{sup 22} W Hz{sup –1}. Using these data, we predict future 1.4 GHz all-sky surveys with a resolution of ∼10 arcsec and a sensitivity of 10 μJy will detect of the order of 560,000 extended low-surface-brightness radio sources of which 440,000 will have a BT morphology.« less

Dark matter detection in supersymmetric models with non-universal gaugino masses

NASA Astrophysics Data System (ADS)

Park, Eun-Kyung

SUSY is one of the most promising new physics ideas, and will soon be tested at high energy accelerators like the CERN LHC. Moreover SUSY provides a good candidate for cold dark matter (CDM). In this dissertation, we investigated phenomenology of SUSY models with non-universal gaugino masses (NUGM) at colliding experiments using event generators such as ISAJET and examined direct and indirect detection rates of relic neutralino CDM in the universe. The motivation of these models is that in most of mSUGRA parameter space, the relic density WZ1˜ h2 is considerably larger than the WMAP measurement, and it is well known that if non-universal gaugino masses are allowed, then qualitatively new possibilities arise that are not realized in the mSUGRA model. Our first NUGM attempt is to allow a mixed wino-bino lightest SUSY particle (LSP) by lowering SU(2) gaugino mass M2 at the weak scale from its mSUGRA value while keeping the hypercharge gaugino mass M1 fixed (Mixed Wino Dark Matter). In this model, wino-like Z˜1 with sufficiently low M2 compared to M1 enhances Z˜1Z˜ 1 → W+1W-1 annihilations to reach the WMAP measured relic density. The second attempt is study on the NUGM model with different signs of M 1 and M2 (Bino-Wino Co-Annihilation Scenario). In this case, there is little mixing, so that Z˜1 remains nearly a pure bino or a pure wino. By increasing M1 ≃ M 2, enhanced bino-wino co-annihilation can achieve the relic neutralino abundance. The final attempt of NUGM models is lowering the SU(3) gaugino mass to diminish the effect of the large top quark Yukawa coupling in the running of the higgs mass, so that the value of superpotential mu parameter gets efficiently low to give rise to mixed higgsino dark matter (Mixed Higgsino Dark Matter). Consequences of these NUGM model studies show us that relaxing universality of gaugino masses in SUSY models leads to enhanced direct and indirect dark matter detection rates and reduced mZ2˜-m Z1˜ mass gap so that the LHC and ILC can distinguish each NUGM model from others. Finally, we found that models with well-tempered neutralinos, where the composition of the neutralino is adjusted to give observed relic density, yield target cross sections which are detectable at proposed experiments.

A neglected - but not negligible - carbon reservoir in the Italian forests: relic charcoal kiln soils.

NASA Astrophysics Data System (ADS)

Mastrolonardo, Giovanni; Francioso, Ornella; Carrari, Elisa; Brogi, Cristiana; Venturi, Martina; Certini, Giacomo

2017-04-01

Charcoal production in forests is one of the oldest human activities in Italy and the other European countries. Here, 3 thousand years ago civilizations were already used to convert wood into charcoal for energetic and metallurgic purposes. The technique for making charcoal remained substantially unchanged in time: wood piles covered with turf were built in appositely shaped emplacements, and then left to pyrolyse for days under controlled semi-anoxic conditions. This widespread activity lasted until a few decades ago, leaving as legacy a plethora of repeatedly used emplacements where soil shows a thick top layer very rich in charcoal. Despite the high frequency of relic charcoal kilns in the European forests, no studies aimed at accurately determining their C stock to assess their relevance as C sink in forest environment. In this work, we studied some relic charcoal kilns in a mixed oak forest at Marsiliana, Tuscany, central Italy, where charcoal production was enduring and massive at least since the Middle age. At Marsiliana, density of charcoal kiln sites was not uniform within the forest areas as it mostly depends on biomass availability. According to the aspect, northerly or southerly, we recognized two main forest areas where kiln sites density ranged between 2 and 3 sites per hectare. In general, the C content in the kiln soils was eight times the one in the surrounding soil, with just one third of the C in the form of pyrogenic C. Hence, natural organic carbon content was significantly higher in the kiln soils. Such a finding confirms that charcoal gives a substantial contribution to the C stock in the kilns but does not fully account for their particular richness in C. It has been thus hypothesized that charcoal is somehow able to stimulate the accumulation of native soil organic matter. At Marsiliana forest, relic charcoal kilns soils cover less than 0.5% of total surface. Nonetheless, their contribution to the total C stock in the top soil (30 cm) ranged between 2.5% and 15%, that is 1.2% to 4.2% of the C stored in the whole forest ecosystem, including litter, deadwood and above and below biomass. Taking into account the very long residence time of pyrogenic C in soil, charcoal kilns have great environmental significance in terms of climate change mitigation. The results of this study stress the importance of safeguarding relic charcoal kilns as a significant C reservoir, as well as a precious historical memory of the customs and traditions of past generations.

From direct detection to relic abundance: the case of proton-philic spin-dependent inelastic Dark Matter

DOE Office of Scientific and Technical Information (OSTI.GOV)

Scopel, Stefano; Yu, Hyeonhye, E-mail: scopel@sogang.ac.kr, E-mail: skyh2yu@gmail.com

We discuss strategies to make inferences on the thermal relic abundance of a Weakly Interacting Massive Particle (WIMP) when the same effective dimension-six operator that explains an experimental excess in direct detection is assumed to drive decoupling at freeze-out, and apply them to the explicit scenario of WIMP inelastic up-scattering with spin-dependent couplings to protons (proton-philic Spin-dependent Inelastic Dark Matter, pSIDM), a phenomenological set-up containing two Dark Matter (DM) particles χ{sub 1} and χ{sub 2} with masses m {sub χ}= m {sub χ{sub 1}} and m {sub χ{sub 2}}= m {sub χ}+δ that we have shown in a previous papermore » to explain the DAMA effect in compliance with the constraints from other detectors. We also update experimental constraints on pSIDM, extend the analysis to the most general spin-dependent momentum-dependent interactions allowed by non-relativistic Effective Field Theory (EFT), and consider for the WIMP velocity distribution in our Galaxy f ( v ) both a halo-independent approach and a standard Maxwellian. Under these conditions we find that the DAMA effect can be explained in terms of the particle χ{sub 1} in compliance with all the other constraints for all the analyzed EFT couplings and also for a Maxwellian f ( v ). As far as the relic abundance is concerned, we show that the problem of calculating it by using direct detection data to fix the model parameters is affected by a strong sensitivity on f ( v ) and by the degeneracy between the WIMP local density ρ{sub χ} and the WIMP-nucleon scattering cross section, since ρ{sub χ} must be rescaled with respect to the observed DM density in the neighborhood of the Sun when the calculated relic density Ω is smaller than the observed one Ω{sub 0}. As a consequence, a DM direct detection experiment is not directly sensitive to the physical cut-off scale of the EFT, but on some dimensional combination that does not depend on the actual value of Ω. However, such degeneracy can be used to develop a consistency test on the possibility that the WIMP is a thermal relic in the first place. When we apply it to the pSIDM scenario we find that only a WIMP with the standard spin-dependent interaction O=χ-bar {sub 1γ}{sup μ}γ{sup 5χ{sub 2}} q-bar γ{sub μ}γ{sup 5} q + h.c. with quarks can be a thermal relic for, approximately, 10 GeV\\;≲ m {sub χ}≲ 16 GeV, 17 keV\\;≲ δ≲ 28 keV, and a large uncertainty on Ω, 6× 10{sup −7}Ω{sub 0≲} Ω ≲ Ω{sub 0}. In order for the scenario to work the WIMP galactic velocity distribution must depart from a Maxwellian. Moreover, all the χ{sub 2} states must have already decayed today, and this requires some additional mechanism besides that provided by the O operator.« less

Tracking Galaxy Evolution Through Low-Frequency Radio Continuum Observations using SKA and Citizen-Science Research using Multi-Wavelength Data

NASA Astrophysics Data System (ADS)

Hota, Ananda; Konar, C.; Stalin, C. S.; Vaddi, Sravani; Mohanty, Pradeepta K.; Dabhade, Pratik; Dharmik Bhoga, Sai Arun; Rajoria, Megha; Sethi, Sagar

2016-12-01

We present a brief review of progress in the understanding of general spiral and elliptical galaxies, through merger, star formation and AGN activities. With reference to case studies performed with the GMRT, we highlight the unique aspects of studying galaxies in the radio wavelengths where powerful quasars and bright radio galaxies are traditionally the dominating subjects. Though AGN or quasar activity is extremely energetic, it is extremely short-lived. This justify focussing on transitional galaxies to find relic-evidences of the immediate past AGN-feedback which decide the future course of evolution of a galaxy. Relic radio lobes can be best detected in low frequency observations with the GMRT, LOFAR and in future SKA. The age of these relic radio plasma can be as old as a few hundred Myr. There is a huge gap between this and what is found in optical bands. The very first relic-evidences of a past quasar activity (Hanny's Voorwerp) was discovered in 2007 by a Galaxy Zoo citizen-scientist, a school teacher, in the optical bands. This relic is around a few tens of thousand years old. More discoveries needed to match these time-scales with star formation time-scales in AGN host galaxies to better understand black hole galaxy co-evolution process via feedback-driven quenching of star formation. It is now well-accepted that discovery and characterization of such faint fuzzy relic features can be more efficiently done by human eye than a machine. Radio interferometry images are more complicated than optical and need the citizen-scientists to be trained. RAD@home, the only Indian citizen-science research project in astronomy, analysing TIFR GMRT Sky Survey (TGSS) 150 MHz data and observing from the Giant Meterwave Radio Telescope (GMRT), was launched in April 2013. Unique, zero-infrastructure zero-funded design of RAD@home as a collaboratory of 69 trained e-astronomers is briefly described. Some of the new-found objects like episodic radio galaxies, radio-jet and companion galaxy interaction, radio galaxy bent by motion of the intra-filament medium in a Mpc-scale galaxy filament etc. are briefly presented as demonstration of its potential. Citizen-science has not only opened up a new way for astronomy research but also possibly the only promising way to extract maximum science out of the Big Data in the SKA-era. This possibly can convert the Big Data problem into a prospect. Citizen-science can contribute to the knowledge creation in never-seen-before speed and in approach. As it is based on internet, it can provide an equal opportunity of academic-growth to people even in the under-developed regions where we always need to put our optical and radio telescopes. This can liberate the research-activity of city-based research-institutes out of the four brick walls and alleviate various socio-economic and geo-political constraints on growth of citizens educated in undergraduate-level science but located in remote areas.

Deriving all p-brane superalgebras via integrability

NASA Astrophysics Data System (ADS)

Grasso, D. T.; McArthur, I. N.

2018-03-01

In previous work we demonstrated that the enlarged super-Poincare algebras which underlie p-brane and D-brane actions in superstring theory can be directly determined based on the integrability of supersymmetry transformations assigned to fields appearing in Wess-Zumino terms. In that work we derived p-brane superalgebras for p = 2 and 3. Here we extend our previous results and give a compact expression for superalgebras for all valid p.

Improved performance of low cost CuInS2 superstrate-type solar cells using Zinc assisted spray pyrolysis processing

NASA Astrophysics Data System (ADS)

Cheshme Khavar, Amir Hossein; Mahjoub, Ali Reza; Taghavinia, Nima

2017-12-01

Superstrate configuration CuInS2 (CIS) solar cells are fabricated using a spray pyrolysis method. We avoided selenization process, cyanide etching and CdS buffer layer, to keep the process ‘green’. CIS layers are formed by spray pyrolysis of an aqueous precursor ink containing metal chloride salts and thiourea at 350 °C. We investigated the effect of intentional Zn doping on structural, morphological and photovoltaic response of the fabricated CIS films by dissolving ZnCl2 in aqueous precursor solution. At a zinc doping level ranging between 0.25 and 1.00 mol%, Zn doping is found to improve the CIS crystal growth and surface morphology of CIS films. Compared with the performance of the non-doped CIS cell, the Zn-doped CIS solar cell displayed a remarkable efficiency enhancement of 58-97% and the maximum enhancement was obtained at a Zn content of 0.5 mol%. The device structure consists of    and show promising PCE of 4.29 % without any anti-reflection coating. Over the course of 300 d under ambient condition, the fabricated device showed only 1% loss in efficiency.

Critical non-Abelian vortex in four dimensions and little string theory

NASA Astrophysics Data System (ADS)

Shifman, M.; Yung, A.

2017-08-01

As was shown recently, non-Abelian vortex strings supported in four-dimensional N =2 supersymmetric QCD with the U(2) gauge group and Nf=4 quark multiplets (flavors) become critical superstrings. In addition to the translational moduli, non-Abelian strings under consideration carry six orientational and size moduli. Together, they form a ten-dimensional target space required for a superstring to be critical. The target space of the string sigma model is a product of the flat four-dimensional space and a Calabi-Yau noncompact threefold, namely, the conifold. We study closed string states which emerge in four dimensions and identify them with hadrons of four-dimensional N =2 QCD. One massless state was found previously; it emerges as a massless hypermultiplet associated with the deformation of the complex structure of the conifold. In this paper, we find a number of massive states. To this end, we exploit the approach used in LST little string theory, namely, the equivalence between the critical string on the conifold and noncritical c =1 string with the Liouville field and a compact scalar at the self-dual radius. The states we find carry "baryonic" charge (its definition differs from standard). We interpret them as "monopole necklaces" formed (at strong coupling) by the closed string with confined monopoles attached.

Supergravitational conformal Galileons

NASA Astrophysics Data System (ADS)

Deen, Rehan; Ovrut, Burt

2017-08-01

The worldvolume actions of 3+1 dimensional bosonic branes embedded in a five-dimensional bulk space can lead to important effective field theories, such as the DBI conformal Galileons, and may, when the Null Energy Condition is violated, play an essential role in cosmological theories of the early universe. These include Galileon Genesis and "bouncing" cosmology, where a pre-Big Bang contracting phase bounces smoothly to the presently observed expanding universe. Perhaps the most natural arena for such branes to arise is within the context of superstring and M -theory vacua. Here, not only are branes required for the consistency of the theory, but, in many cases, the exact spectrum of particle physics occurs at low energy. However, such theories have the additional constraint that they must be N = 1 supersymmetric. This motivates us to compute the worldvolume actions of N = 1 supersymmetric three-branes, first in flat superspace and then to generalize them to N = 1 supergravitation. In this paper, for simplicity, we begin the process, not within the context of a superstring vacuum but, rather, for the conformal Galileons arising on a co-dimension one brane embedded in a maximally symmetric AdS 5 bulk space. We proceed to N = 1 supersymmetrize the associated worldvolume theory and then generalize the results to N = 1 supergravity, opening the door to possible new cosmological scenarios

Multi-component dark matter through a radiative Higgs portal

DOE PAGES

DiFranzo, Anthony; Univ. of California, Irvine, CA; Rutgers Univ., Piscataway, NJ; ...

2017-01-18

Here, we study a multi-component dark matter model where interactions with the Standard Model are primarily via the Higgs boson. The model contains vector-like fermions charged undermore » $$SU(2)_W \\times U(1)_Y$$ and under the dark gauge group, $$U(1)^\\prime$$. This results in two dark matter candidates. A spin-1 and a spin-1/2 candidate, which have loop and tree-level couplings to the Higgs, respectively. We explore the resulting effect on the dark matter relic abundance, while also evaluating constraints on the Higgs invisible width and from direct detection experiments. Generally, we find that this model is highly constrained when the fermionic candidate is the predominant fraction of the dark matter relic abundance.« less

Impact of semi-annihilation of ℤ{sub 3} symmetric dark matter with radiative neutrino masses

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aoki, Mayumi; Toma, Takashi

2014-09-08

We investigate a ℤ{sub 3} symmetric model with two-loop radiative neutrino masses. Dark matter in the model is either a Dirac fermion or a complex scalar as a result of an unbroken ℤ{sub 3} symmetry. In addition to standard annihilation processes, semi-annihilation of the dark matter contributes to the relic density. We study the effect of the semi-annihilation in the model and find that those contributions are important to obtain the observed relic density. The experimental signatures in dark matter searches are also discussed, where some of them are expected to be different from the signatures of dark matter inmore » ℤ{sub 2} symmetric models.« less

Impact of semi-annihilation of Z{sub 3} symmetric dark matter with radiative neutrino masses

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aoki, Mayumi; Toma, Takashi, E-mail: mayumi@hep.s.kanazawa-u.ac.jp, E-mail: takashi.toma@durham.ac.uk

2014-09-01

We investigate a Z{sub 3} symmetric model with two-loop radiative neutrino masses. Dark matter in the model is either a Dirac fermion or a complex scalar as a result of an unbroken Z{sub 3} symmetry. In addition to standard annihilation processes, semi-annihilation of the dark matter contributes to the relic density. We study the effect of the semi-annihilation in the model and find that those contributions are important to obtain the observed relic density. The experimental signatures in dark matter searches are also discussed, where some of them are expected to be different from the signatures of dark matter inmore » Z{sub 2} symmetric models.« less

Radiative decays of massive relic particles and the submillimeter background

NASA Technical Reports Server (NTRS)

Field, George B.; Walker, Terry P.

1989-01-01

The interaction of the decay photons of an unstable relic particle species with the microwave background radiation is considered. The radiative decays of these particles delay recombination and serve as an energy source for the resultant plasma. Nonrelativistic Compton scattering by these electrons couples the decay photons to the microwave background, producing submillimeter distortions. If the decay products close the universe, they must decay with a radiative branching ratio larger than 2.5 x 10 to the -5th in order to produce recently observed excess submillimeter background radiation. To be consistent with measurements of the UV background, their mass m is much greater than 114 keV and their decay redshift z is much greater than 5200.

Global constraints on vector-like WIMP effective interactions

DOE PAGES

Blennow, Mattias; Coloma, Pilar; Fernandez-Martinez, Enrique; ...

2016-04-07

In this work we combine information from relic abundance, direct detection, cosmic microwave background, positron fraction, gamma rays, and colliders to explore the existing constraints on couplings between Dark Matter and Standard Model constituents when no underlying model or correlation is assumed. For definiteness, we include independent vector-like effective interactions for each Standard Model fermion. Our results show that low Dark Matter masses below 20 GeV are disfavoured at the 3 σ  level with respect to higher masses, due to the tension between the relic abundance requirement and upper constraints on the Dark Matter couplings. Lastly, large couplings are typically onlymore » allowed in combinations which avoid effective couplings to the nuclei used in direct detection experiments.« less

A relic of the Wellcome Tropical Research Laboratories in Khartoum (1903-34).

PubMed

Adeel, Ahmed Awad

2016-01-01

This article explores the origins of an old brass monocular microscope in the Central Laboratory in Khartoum, which used to be the Wellcome Tropical Research Laboratory in Khartoum (1903-1934). Examination of the microscope and review of published literature gave clues to the historical background of this microscope. Identical microscopes were first manufactured by R and J Beck in 1898, and continued to be advertised in 1899. The microscope was probably among the instruments provided by Wellcome for the initial establishment of the laboratories in 1902-1903. The article includes a brief review of the development of light microscopy. The need for preservation and proper restoration of old relics of the Wellcome laboratories in Khartoum is emphasized.

A relic of the Wellcome Tropical Research Laboratories in Khartoum (1903–34)

PubMed Central

2016-01-01

This article explores the origins of an old brass monocular microscope in the Central Laboratory in Khartoum, which used to be the Wellcome Tropical Research Laboratory in Khartoum (1903–1934). Examination of the microscope and review of published literature gave clues to the historical background of this microscope. Identical microscopes were first manufactured by R and J Beck in 1898, and continued to be advertised in 1899. The microscope was probably among the instruments provided by Wellcome for the initial establishment of the laboratories in 1902–1903. The article includes a brief review of the development of light microscopy. The need for preservation and proper restoration of old relics of the Wellcome laboratories in Khartoum is emphasized. PMID:27651557

Lepton flavor violation induced by dark matter

NASA Astrophysics Data System (ADS)

Arcadi, Giorgio; Ferreira, C. P.; Goertz, Florian; Guzzo, M. M.; Queiroz, Farinaldo S.; Santos, A. C. O.

2018-04-01

Guided by gauge principles we discuss a predictive and falsifiable UV complete model where the Dirac fermion that accounts for the cold dark matter abundance in our Universe induces the lepton flavor violation (LFV) decays μ →e γ and μ →e e e as well as μ -e conversion. We explore the interplay between direct dark matter detection, relic density, collider probes and lepton flavor violation to conclusively show that one may have a viable dark matter candidate yielding flavor violation signatures that can be probed in the upcoming experiments. In fact, keeping the dark matter mass at the TeV scale, a sizable LFV signal is possible, while reproducing the correct dark matter relic density and meeting limits from direct-detection experiments.

From the 750 GeV diphoton resonance to multilepton excesses

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bae, Kyu Jung; Chen, Chuan-Ren; Hamaguchi, Koichi

2016-07-01

Weakly coupled models for the 750 GeV diphoton resonance often invoke new particles carrying both color and/or electric charges to mediate loop-induced couplings of the resonance to two gluons and two photons. The new colored particles may not be stable and could decay into final states containing standard model particles. We consider an electroweak doublet of vectorlike quarks (VLQs) carrying electric charges of 5/3 and 2/3, respectively, which mediate the loop-induced couplings of the 750 GeV resonance. If the VLQ has a mass at around 1 TeV, it naturally gives rise to the observed diphoton signal strength while all couplingsmore » remain perturbative up to a high scale. At the same time, if the charge-5/3 VLQ decays into final states containing top quark and W boson, it would contribute to the multilepton excesses observed in both run 1 and run 2 data. It is also possible to incorporate a dark matter candidate in the decay final states to explain the observed relic density.« less

Disappearing inflaton potential via heavy field dynamics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kitajima, Naoya; Takahashi, Fuminobu, E-mail: kitajima@tuhep.phys.tohoku.ac.jp, E-mail: fumi@tuhep.phys.tohoku.ac.jp

2016-02-01

We propose a possibility that the inflaton potential is significantly modified after inflation due to heavy field dynamics. During inflation such a heavy scalar field may be stabilized at a value deviated from the low-energy minimum. In extreme cases, the inflaton potential vanishes and the inflaton becomes almost massless at some time after inflation. Such transition of the inflaton potential has interesting implications for primordial density perturbations, reheating, creation of unwanted relics, dark radiation, and experimental search for light degrees of freedom. To be concrete, we consider a chaotic inflation in supergravity where the inflaton mass parameter is promoted tomore » a modulus field, finding that the inflaton becomes stable after the transition and contributes to dark matter. Another example is a hilltop inflation (also called new inflation) by the MSSM Higgs field which acquires a large expectation value just after inflation, but it returns to the origin after the transition and finally rolls down to the electroweak vacuum. Interestingly, the smallness of the electroweak scale compared to the Planck scale is directly related to the flatness of the inflaton potential.« less

The privileged burial of the Pava Pieve (Siena, 8th Century AD).

PubMed

Ricci, Paola; Mongelli, Valeria; Vitiello, Angelica; Campana, Stefano; Sirignano, Carmina; Rubino, Mauro; Fornaciari, Gino; Lubritto, Carmine

2012-10-30

The 6(th) archaeological excavation campaign performed at the 'Pieve di Pava' (San Giovanni d'Asso, Siena, Italy) unearthed a privileged stone burial of a single individual (US 2378), covered by a monolithic slab and placed in front of an altar. The skeletal remains of a young male (18-20 years old), not in anatomical connection, were found at the bottom floor of a tomb (160 cm long, 40 cm large and over 70 cm deep). A multidisciplinary study has been carried out concerning that privileged bone burial. The study combines paleopathology studies, stable isotope palaeodietary reconstruction, radiocarbon dating and archaeological analyses. (14)  C dating of the skeleton revealed a date between 650 and 688 AD. Stable isotope analysis (δ(18) O, δ(13) C, δ(15) N) attested that he was probably a member of the local population, whose diet was rather rich in animal proteins. The paleopathological study diagnosed a case of acromesomelic dysplasia, a congenital anomaly with disproportion of the limbs. Archaeological evidence regarding the circular delimitation of the bones suggested that the skeleton was a secondary deposition, transported to the church in a sack. We argue that the relic was used for the re-consecration of the church, following the restoration work in the 8(th) century. We conclude that the skeleton belonged to an eminent personage (e.g., either the member of a local elite family or a saint). Copyright © 2012 John Wiley & Sons, Ltd.

Dangerous angular Kaluza-Klein/glueball relics in string theory cosmology

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dufaux, J. F.; CITA, University of Toronto, 60 St. George st., Toronto, ON M5S 3H8; Kofman, L.

2008-07-15

The presence of Kaluza-Klein (KK) particles in the universe is a potential manifestation of string theory cosmology. In general, they can be present in the high temperature bath of the early universe. In particular examples, string theory inflation often ends with brane-antibrane annihilation followed by the energy cascading through massive closed string loops to KK modes which then decay into lighter standard model particles. However, massive KK modes in the early universe may become dangerous cosmological relics if the inner manifold contains warped throat(s) with approximate isometries. In the complimentary picture, in the AdS/CFT dual gauge theory with extra isometries,more » massive glueballs of various spins become the dangerous cosmological relics. The decay of these angular KK modes/glueballs, located around the tip of the throat, is caused by isometry breaking which results from gluing the throat to the compact Calabi-Yau (CY) manifold. We address the problem of these angular KK particles/glueballs, studying their interactions and decay channels, from the theory side, and the resulting cosmological constraints on the warped compactification parameters, from the phenomenology side. The abundance and decay time of the long-lived nonrelativistic angular KK modes depend strongly on the parameters of the warped geometry, so that observational constraints rule out a significant fraction of the parameter space. In particular, the coupling of the angular KK particles can be weaker than gravitational.« less

The search for the missing link: a relic plastid in Perkinsus?

PubMed

Fernández Robledo, José A; Caler, Elisabet; Matsuzaki, Motomichi; Keeling, Patrick J; Shanmugam, Dhanasekaran; Roos, David S; Vasta, Gerardo R

2011-10-01

Perkinsus marinus (Phylum Perkinsozoa) is a protozoan parasite that has devastated natural and farmed oyster populations in the USA, significantly affecting the shellfish industry and the estuarine environment. The other two genera in the phylum, Parvilucifera and Rastrimonas, are parasites of microeukaryotes. The Perkinsozoa occupies a key position at the base of the dinoflagellate branch, close to its divergence from the Apicomplexa, a clade that includes parasitic protista, many harbouring a relic plastid. Thus, as a taxon that has also evolved toward parasitism, the Perkinsozoa has attracted the attention of biologists interested in the evolution of this organelle, both in its ultrastructure and the conservation, loss or transfer of its genes. A review of the recent literature reveals mounting evidence in support of the presence of a relic plastid in P. marinus, including the presence of multimembrane structures, characteristic metabolic pathways and proteins with a bipartite N-terminal extension. Further, these findings raise intriguing questions regarding the potential functions and unique adaptation of the putative plastid and/or plastid genes in the Perkinsozoa. In this review we analyse the above-mentioned evidence and evaluate the potential future directions and expected benefits of addressing such questions. Given the rapidly expanding molecular/genetic resources and methodological toolbox for Perkinsus spp., these organisms should complement the currently established models for investigating plastid evolution within the Chromalveolata. Copyright © 2011. Published by Elsevier Ltd.

Vavilov–Cherenkov radiation when cosmic rays pass through the relic photon gas and when fast charged particles traverse an optical laser beam

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chefranov, S. G., E-mail: schefranov@mail.ru

2016-07-15

Using a new [9, 10] quantum theory of Vavilov–Cherenkov radiation (VCR) based on Abraham’s theory, we show that a threshold VCR effect can be excited by the relic photon gas when relativistic charged cosmic-ray particles with γ ≥ γ{sub th} ≈ 1.9 × 10{sup 10} (where γ{sup –2} = 1–v{sup 2}/c{sup 2}, v is the particle speed, and c is the speed of light in a vacuum) pass through it. This is compatible with the well-known GZK cutoff [7, 8] at γ ≈ 10{sup 11}. We have obtained the condition γ > γ{sub th} ≈ 2.1 × 10{sup 2} formore » the appearance of VCR when a sufficiently fast charged particle (an electron, a proton, or a nucleus) passes through intense laser radiation. This condition ensures that VCR can be observed experimentally (e.g., on the Large Hadron Collider) without invoking any additional conditions required from the currently existing estimate of γth > 8.8 × 10{sup 4} [13] based on the now universally accepted quantum theory of VCR, which follows from Minkowski’s theory (and which gives an estimate of γ > 10{sup 21} when excited by the relic photon gas).« less

Simplified phenomenology for colored dark sectors

NASA Astrophysics Data System (ADS)

El Hedri, Sonia; Kaminska, Anna; de Vries, Maikel; Zurita, Jose

2017-04-01

We perform a general study of the relic density and LHC constraints on simplified models where the dark matter coannihilates with a strongly interacting particle X. In these models, the dark matter depletion is driven by the self-annihilation of X to pairs of quarks and gluons through the strong interaction. The phenomenology of these scenarios therefore only depends on the dark matter mass and the mass splitting between dark matter and X as well as the quantum numbers of X. In this paper, we consider simplified models where X can be either a scalar, a fermion or a vector, as well as a color triplet, sextet or octet. We compute the dark matter relic density constraints taking into account Sommerfeld corrections and bound state formation. Furthermore, we examine the restrictions from thermal equilibrium, the lifetime of X and the current and future LHC bounds on X pair production. All constraints are comprehensively presented in the mass splitting versus dark matter mass plane. While the relic density constraints can lead to upper bounds on the dark matter mass ranging from 2 TeV to more than 10 TeV across our models, the prospective LHC bounds range from 800 to 1500 GeV. A full coverage of the strongly coannihilating dark matter parameter space would therefore require hadron colliders with significantly higher center-of-mass energies.

The shadow world of superstring theories

NASA Technical Reports Server (NTRS)

Kolb, E. W.; Turner, M. S.; Seckel, D.

1985-01-01

Some possible astrophysical and cosmological implications of 'shadow matter', a form of matter which only interacts gravitationally with ordinary matter and which may or may not be identical in its properties to ordinary matter, are considered. The possible existence, amount, and location of shadow matter in the solar system are discussed, and the significance of shadow matter for primordial nucleosynthesis, macroscopic asymmetry, baryogenesis, double-bubble inflation, and asymmetric microphysics is addressed. Massive shadow states are discussed.

Light dark matter through assisted annihilation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dey, Ujjal Kumar; Maity, Tarak Nath; Ray, Tirtha Sankar, E-mail: ujjal@cts.iitkgp.ernet.in, E-mail: tarak.maity.physics@gmail.com, E-mail: tirthasankar.ray@gmail.com

2017-03-01

In this paper we investigate light dark matter scenarios where annihilation to Standard Model particles at tree-level is kinematically forbidden. In such cases annihilation can be aided by massive Standard Model-like species, called assisters , in the initial state that enhances the available phase space opening up novel tree-level processes. We investigate the feasibility of such non-standard assisted annihilation processes to reproduce the observed relic density of dark matter. We present a simple scalar dark matter-scalar assister model where this is realised. We find that if the dark matter and assister are relatively degenerate the required relic density can bemore » achieved for a keV-MeV scale dark matter. We briefly discuss the cosmological constraints on such dark matter scenarios.« less

'The Grange', Tasmania: survival of a unique suite of 1874 transit of Venus relics

NASA Astrophysics Data System (ADS)

Orchiston, Wayne; Buchanan, Alex

2004-06-01

One of the two US expeditions in Australia for the 1874 transit of Venus was based in Campbell Town, Tasmania. While the transit was observed from this site and some of the photographs were used in the subsequent investigation of the solar parallax, its main claim to fame is the physical vestiges of the transit programme that have survived there through to the present day. These comprise foundations for instruments, two piers associated with the photographic telescope, and one of the prefabricated observatory buildings. In addition, a copy of a photograph of the transit is preserved in the Queen Victoria Museum and Art Gallery in nearby Launceston. Collectively these form a unique suite of 1874 transit of Venus relics, and are of international importance.

Annihilation of singlet fermionic dark matter into two photons

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ettefaghi, M.M.; Moazzemi, R., E-mail: mettefaghi@qom.ac.ir, E-mail: r.moazzemi@qom.ac.ir

2013-02-01

We consider an extension of the standard model in which a singlet fermionic particle, to serve as cold dark matter, and a singlet Higgs are added. We perform a reanalysis on the free parameters. In particular, demanding a correct relic abundance of dark matter, we derive and plot the coupling of the singlet fermion with the singlet Higgs, g{sub s}, versus the dark matter mass. We analytically compute the pair annihilation cross section of singlet fermionic dark matter into two photons. The thermally averaged of this cross section is calculated for wide range of energies and plotted versus dark mattermore » mass using g{sub s} consistent with the relic abundance condition. We also compare our results with the Fermi-Lat observations.« less

Fermi gamma-ray imaging of a radio galaxy.

PubMed

Abdo, A A; Ackermann, M; Ajello, M; Atwood, W B; Baldini, L; Ballet, J; Barbiellini, G; Bastieri, D; Baughman, B M; Bechtol, K; Bellazzini, R; Berenji, B; Blandford, R D; Bloom, E D; Bonamente, E; Borgland, A W; Bregeon, J; Brez, A; Brigida, M; Bruel, P; Burnett, T H; Buson, S; Caliandro, G A; Cameron, R A; Caraveo, P A; Casandjian, J M; Cavazzuti, E; Cecchi, C; Celik, O; Chekhtman, A; Cheung, C C; Chiang, J; Ciprini, S; Claus, R; Cohen-Tanugi, J; Colafrancesco, S; Cominsky, L R; Conrad, J; Costamante, L; Cutini, S; Davis, D S; Dermer, C D; de Angelis, A; de Palma, F; Digel, S W; do Couto e Silva, E; Drell, P S; Dubois, R; Dumora, D; Farnier, C; Favuzzi, C; Fegan, S J; Finke, J; Focke, W B; Fortin, P; Fukazawa, Y; Funk, S; Fusco, P; Gargano, F; Gasparrini, D; Gehrels, N; Georganopoulos, M; Germani, S; Giebels, B; Giglietto, N; Giordano, F; Giroletti, M; Glanzman, T; Godfrey, G; Grenier, I A; Grove, J E; Guillemot, L; Guiriec, S; Hanabata, Y; Harding, A K; Hayashida, M; Hays, E; Hughes, R E; Jackson, M S; Jóhannesson, G; Johnson, A S; Johnson, T J; Johnson, W N; Kamae, T; Katagiri, H; Kataoka, J; Kawai, N; Kerr, M; Knödlseder, J; Kocian, M L; Kuss, M; Lande, J; Latronico, L; Lemoine-Goumard, M; Longo, F; Loparco, F; Lott, B; Lovellette, M N; Lubrano, P; Madejski, G M; Makeev, A; Mazziotta, M N; McConville, W; McEnery, J E; Meurer, C; Michelson, P F; Mitthumsiri, W; Mizuno, T; Moiseev, A A; Monte, C; Monzani, M E; Morselli, A; Moskalenko, I V; Murgia, S; Nolan, P L; Norris, J P; Nuss, E; Ohsugi, T; Omodei, N; Orlando, E; Ormes, J F; Paneque, D; Parent, D; Pelassa, V; Pepe, M; Pesce-Rollins, M; Piron, F; Porter, T A; Rainò, S; Rando, R; Razzano, M; Razzaque, S; Reimer, A; Reimer, O; Reposeur, T; Ritz, S; Rochester, L S; Rodriguez, A Y; Romani, R W; Roth, M; Ryde, F; Sadrozinski, H F-W; Sambruna, R; Sanchez, D; Sander, A; Saz Parkinson, P M; Scargle, J D; Sgrò, C; Siskind, E J; Smith, D A; Smith, P D; Spandre, G; Spinelli, P; Starck, J-L; Stawarz, Ł; Strickman, M S; Suson, D J; Tajima, H; Takahashi, H; Takahashi, T; Tanaka, T; Thayer, J B; Thayer, J G; Thompson, D J; Tibaldo, L; Torres, D F; Tosti, G; Tramacere, A; Uchiyama, Y; Usher, T L; Vasileiou, V; Vilchez, N; Vitale, V; Waite, A P; Wallace, E; Wang, P; Winer, B L; Wood, K S; Ylinen, T; Ziegler, M; Hardcastle, M J; Kazanas, D

2010-05-07

The Fermi Gamma-ray Space Telescope has detected the gamma-ray glow emanating from the giant radio lobes of the radio galaxy Centaurus A. The resolved gamma-ray image shows the lobes clearly separated from the central active source. In contrast to all other active galaxies detected so far in high-energy gamma-rays, the lobe flux constitutes a considerable portion (greater than one-half) of the total source emission. The gamma-ray emission from the lobes is interpreted as inverse Compton-scattered relic radiation from the cosmic microwave background, with additional contribution at higher energies from the infrared-to-optical extragalactic background light. These measurements provide gamma-ray constraints on the magnetic field and particle energy content in radio galaxy lobes, as well as a promising method to probe the cosmic relic photon fields.

5 CFR 180.105 - Claims not allowed.

Code of Federal Regulations, 2012 CFR

2012-01-01

... articles of gold, silver, other precious metals, paintings, antiques other than bulky furnishings, relics... articles acquired at the request of others and articles for sale. (9) Property used for business. Claims...

5 CFR 180.105 - Claims not allowed.

Code of Federal Regulations, 2013 CFR

2013-01-01

... articles of gold, silver, other precious metals, paintings, antiques other than bulky furnishings, relics... articles acquired at the request of others and articles for sale. (9) Property used for business. Claims...

5 CFR 180.105 - Claims not allowed.

Code of Federal Regulations, 2011 CFR

2011-01-01

... articles of gold, silver, other precious metals, paintings, antiques other than bulky furnishings, relics... articles acquired at the request of others and articles for sale. (9) Property used for business. Claims...

5 CFR 180.105 - Claims not allowed.

Code of Federal Regulations, 2010 CFR

2010-01-01

... articles of gold, silver, other precious metals, paintings, antiques other than bulky furnishings, relics... articles acquired at the request of others and articles for sale. (9) Property used for business. Claims...

5 CFR 180.105 - Claims not allowed.

Code of Federal Regulations, 2014 CFR

2014-01-01

... articles of gold, silver, other precious metals, paintings, antiques other than bulky furnishings, relics... articles acquired at the request of others and articles for sale. (9) Property used for business. Claims...

Flooded Dark Matter and S level rise

NASA Astrophysics Data System (ADS)

Randall, Lisa; Scholtz, Jakub; Unwin, James

2016-03-01

Most dark matter models set the dark matter relic density by some interaction with Standard Model particles. Such models generally assume the existence of Standard Model particles early on, with the dark matter relic density a later consequence of those interactions. Perhaps a more compelling assumption is that dark matter is not part of the Standard Model sector and a population of dark matter too is generated at the end of inflation. This democratic assumption about initial conditions does not necessarily provide a natural value for the dark matter relic density, and furthermore superficially leads to too much entropy in the dark sector relative to ordinary matter. We address the latter issue by the late decay of heavy particles produced at early times, thereby associating the dark matter relic density with the lifetime of a long-lived state. This paper investigates what it would take for this scenario to be compatible with observations in what we call Flooded Dark Matter (FDM) models and discusses several interesting consequences. One is that dark matter can be very light and furthermore, light dark matter is in some sense the most natural scenario in FDM as it is compatible with larger couplings of the decaying particle. A related consequence is that the decay of the field with the smallest coupling and hence the longest lifetime dominates the entropy and possibly the matter content of the Universe, a principle we refer to as "Maximum Baroqueness". We also demonstrate that the dark sector should be colder than the ordinary sector, relaxing the most stringent free-streaming constraints on light dark matter candidates. We will discuss the potential implications for the core-cusp problem in a follow-up paper. The FDM framework will furthermore have interesting baryogenesis implications. One possibility is that dark matter is like the baryon asymmetry and both are simultaneously diluted by a late entropy dump. Alternatively, FDM is compatible with an elegant non-thermal leptogenesis implementation in which decays of a heavy right-handed neutrino lead to late time reheating of the Standard Model degrees of freedom and provide suitable conditions for creation of a lepton asymmetry.

Superstrings

ScienceCinema

Lincoln, Don

2018-01-16

The quest to find the ultimate building blocks of nature is one of the oldest in all of physics. While we are far from knowing the answer to that question, one intriguing proposed answer is that all matter is composed of tiny “strings.” The known particles are simply different vibrational patterns of these strings. In this video, Fermilab’s Dr. Don Lincoln explains this idea, using interesting and accessible examples of real-world vibrations.

Supergravitational conformal Galileons

DOE PAGES

Deen, Rehan; Ovrut, Burt

2017-08-04

The worldvolume actions of 3+1 dimensional bosonic branes embedded in a five-dimensional bulk space can lead to important effective field theories, such as the DBI conformal Galileons, and may, when the Null Energy Condition is violated, play an essential role in cosmological theories of the early universe. These include Galileon Genesis and “bouncing” cosmology, where a pre-Big Bang contracting phase bounces smoothly to the presently observed expanding universe. Perhaps the most natural arena for such branes to arise is within the context of superstring and M -theory vacua. Here, not only are branes required for the consistency of the theory,more » but, in many cases, the exact spectrum of particle physics occurs at low energy. However, such theories have the additional constraint that they must be N = 1 supersymmetric. This motivates us to compute the worldvolume actions of N = 1 supersymmetric three-branes, first in flat superspace and then to generalize them to N = 1 supergravitation. In this paper, for simplicity, we begin the process, not within the context of a superstring vacuum but, rather, for the conformal Galileons arising on a co-dimension one brane embedded in a maximally symmetric AdS 5 bulk space. We proceed to N = 1 supersymmetrize the associated worldvolume theory and then generalize the results to N = 1 supergravity, opening the door to possible new cosmological scenarios« less

Supergravitational conformal Galileons

DOE Office of Scientific and Technical Information (OSTI.GOV)

Deen, Rehan; Ovrut, Burt

The worldvolume actions of 3+1 dimensional bosonic branes embedded in a five-dimensional bulk space can lead to important effective field theories, such as the DBI conformal Galileons, and may, when the Null Energy Condition is violated, play an essential role in cosmological theories of the early universe. These include Galileon Genesis and “bouncing” cosmology, where a pre-Big Bang contracting phase bounces smoothly to the presently observed expanding universe. Perhaps the most natural arena for such branes to arise is within the context of superstring and M -theory vacua. Here, not only are branes required for the consistency of the theory,more » but, in many cases, the exact spectrum of particle physics occurs at low energy. However, such theories have the additional constraint that they must be N = 1 supersymmetric. This motivates us to compute the worldvolume actions of N = 1 supersymmetric three-branes, first in flat superspace and then to generalize them to N = 1 supergravitation. In this paper, for simplicity, we begin the process, not within the context of a superstring vacuum but, rather, for the conformal Galileons arising on a co-dimension one brane embedded in a maximally symmetric AdS 5 bulk space. We proceed to N = 1 supersymmetrize the associated worldvolume theory and then generalize the results to N = 1 supergravity, opening the door to possible new cosmological scenarios« less

The birth of the universe in a new G-theory approach

NASA Astrophysics Data System (ADS)

Sepehri, Alireza; Pincak, Richard

2017-02-01

Recently, Padmanabhan has discussed that the expansion of the cosmic space is due to the difference between the number of degrees of freedom on the boundary surface and the number of degrees of freedom in a bulk region. Now, a natural question arises that how these degrees of freedom emerged from nothing? We try to address this issue in a new theory which is more complete than M-theory and reduces to it with some limitations. In M-theory, there is no stable object like stable M3-branes that our universe is formed on it and for this reason cannot help us to explain cosmological events. In this research, we propose a new theory, named G-theory which could be the mother of M-theory and superstring theory. In G-theory, at the beginning, two types of G0-branes, one with positive energy and one with negative energy are produced from nothing in 14 dimensions. Then, these branes are compactified on three circles via two different ways (symmetrically and anti-symmetrically), and two bosonic and fermionic parts of action for M0-branes are produced. By joining M0-branes, supersymmetric Mp-branes are created which contain the equal number of degrees of freedom for fermions and bosons. Our universe is constructed on one of Mp-branes and other Mp-brane and extra energy play the role of bulk. By dissolving extra energy which is produced by compacting actions of Gp-branes, into our universe, the number of degrees of freedom on it and also its scale factor increase and universe expands. We test G-theory with observations and find that the magnitude of the slow-roll parameters and the tensor-to-scalar ratio in this model are very much smaller than one which are in agreement with predictions of experimental data. Finally, we consider the origin of the extended theories of gravity in G-theory and show that these theories could be anomaly free.

Smoot Cosmology Group

Science.gov Websites

Fuzz, FORBES ASAP article on the Arrow of Time by George Smoot. Lecture Archives: The relic radiation from the big bang begining of the Universe. Antimatter in the Universe (Physics 24 Lecture by George

Sulphur Spring: Busy Intersection and Possible Martian Analogue

NASA Technical Reports Server (NTRS)

Nankivell, A.; Andre, N.; Thomas-Keprta, K.; Allen, C.; McKay, D.

2000-01-01

Life in extreme environments exhibiting conditions similar to early Earth and Mars, such as Sulphur Spring, may harbor microbiota serving as both relics from the past as well as present day Martian analogues.

Fermi Gamma-Ray Imaging of a Radio Galaxy

DOE PAGES

Abdo, A. A.; Ackermann, M.; Ajello, M.; ...

2010-04-01

The Fermi Gamma-ray Space Telescope has detected the γ-ray glow emanating from the giant radio lobes of the radio galaxy Centaurus A. The resolved γ-ray image shows the lobes clearly separated from the central active source. In contrast to all other active galaxies detected so far in high-energy γ-rays, the lobe flux constitutes a considerable portion (greater than one-half) of the total source emission. The γ-ray emission from the lobes is interpreted as inverse Compton–scattered relic radiation from the cosmic microwave background, with additional contribution at higher energies from the infrared-to-optical extragalactic background light. In conclusion, these measurements provide γ-raymore » constraints on the magnetic field and particle energy content in radio galaxy lobes, as well as a promising method to probe the cosmic relic photon fields.« less

Red-Supergiant and Supernova Rate Problems: Implication for the Relic Supernova Neutrino Spectrum

NASA Astrophysics Data System (ADS)

Hidaka, J.; Kajino, T.; Mathews, G. J.

2016-08-01

Direct observations of core-collapse supernovae (SNe) and their red supergiant (RSG) progenitors suggest that the upper mass limit of RSGs may be only about 16.5{--}18{M}⊙ , while the standard theoretical value is as much as 25{M}⊙ . We investigate the possibility that RSGs with m\\gt 16.5{--}18{M}⊙ end their lives as failed supernovae (fSNe) and analyze their contribution to the relic supernova neutrino spectrum. We show that adopting this mass limit simultaneously solves both the RSG problem and the supernova rate problem. In addition, energetic neutrinos that originated from fSNe are sensitive to the explosion mechanism, and in particular, to the nuclear equation of state (EOS). We show that this solution to the RSG problem might also be used to constrain the EOS for failed supernovae.

Relic gravitational waves and extended inflation

NASA Technical Reports Server (NTRS)

Turner, Michael S.; Wilczek, Frank

1990-01-01

In extended inflation, a new version of inflation where the transition from the false-vacuum phase to a radiation-dominated Universe is accomplished by bubble nucleation and percolation, bubble collisions supply a potent-and potentially detectable-source of gravitational waves. The present energy density in relic gravity waves from bubble collisions is expected to be about 10(exp -5) of closure density-many orders of magnitude greater than that of the gravity waves produced by quantum fluctuations. Their characteristic wavelength depends upon the reheating temperature T(sub RH): lambda is approximately 10(exp 4) cm (10(exp 14) GeV/T(sub RH)). If large numbers of black holes are produced, a not implausible outcome, they will evaporate producing comparable amounts of shorter wavelength waves, lambda is approximately 10(exp -6) cm (T(sub RH)/10(exp 14) GeV).

Planetary rings as relics of plasma pre-rings

NASA Astrophysics Data System (ADS)

Rabinovich, B. I.

2007-02-01

A possibility is discussed that the rings of large planets observed in the modern epoch are relics of some pre-rings consisting of magnetized plasma (according to a hypothesis by H. Alfven). The solution to a model problem published in [36, 37] is used. Its main result is a mechanism of stratification of an evolutionally mature plasma pre-ring into a large number of narrow elite rings separated by anti-rings (gaps). Another result is the theoretical substantiation of the presence in the near-planetary space of a region of existence and stability (in what follows it is referred to as ES-region) of plasma rings. The data obtained in the course of the Voyager, Galileo, and Cassini missions are used below for verification of the model on which the solutions presented in [36, 37] are based.

Mechanism for thermal relic dark matter of strongly interacting massive particles.

PubMed

Hochberg, Yonit; Kuflik, Eric; Volansky, Tomer; Wacker, Jay G

2014-10-24

We present a new paradigm for achieving thermal relic dark matter. The mechanism arises when a nearly secluded dark sector is thermalized with the standard model after reheating. The freeze-out process is a number-changing 3→2 annihilation of strongly interacting massive particles (SIMPs) in the dark sector, and points to sub-GeV dark matter. The couplings to the visible sector, necessary for maintaining thermal equilibrium with the standard model, imply measurable signals that will allow coverage of a significant part of the parameter space with future indirect- and direct-detection experiments and via direct production of dark matter at colliders. Moreover, 3→2 annihilations typically predict sizable 2→2 self-interactions which naturally address the "core versus cusp" and "too-big-to-fail" small-scale structure formation problems.

MeV dark matter complementarity and the dark photon portal

NASA Astrophysics Data System (ADS)

Dutra, Maíra; Lindner, Manfred; Profumo, Stefano; Queiroz, Farinaldo S.; Rodejohann, Werner; Siqueira, Clarissa

2018-03-01

We discuss the phenomenology of an MeV-scale Dirac fermion coupled to the Standard Model through a dark photon with kinetic mixing with the electromagnetic field. We compute the dark matter relic density and explore the interplay of direct detection and accelerator searches for dark photons. We show that precise measurements of the temperature and polarization power spectra of the Cosmic Microwave Background Radiation lead to stringent constraints, leaving a small window for the thermal production of this MeV dark matter candidate. The forthcoming MeV gamma-ray telescope e-ASTROGAM will offer important and complementary opportunities to discover dark matter particles with masses below ~ 10 MeV . Lastly, we discuss how a late-time inflation episode and freeze-in production could conspire to yield the correct relic density while being consistent with existing and future constraints.

Search for low-frequency diffuse radio emission around a shock in the massive galaxy cluster MACS J0744.9+3927

NASA Astrophysics Data System (ADS)

Wilber, A.; Brüggen, M.; Bonafede, A.; Rafferty, D.; Savini, F.; Shimwell, T.; van Weeren, R. J.; Botteon, A.; Cassano, R.; Brunetti, G.; De Gasperin, F.; Wittor, D.; Hoeft, M.; Birzan, L.

2018-05-01

Merging galaxy clusters produce low-Mach-number shocks in the intracluster medium. These shocks can accelerate electrons to relativistic energies that are detectable at radio frequencies. MACS J0744.9+3927 is a massive [M500 = (11.8 ± 2.8) × 1014 M⊙], high-redshift (z = 0.6976) cluster where a Bullet-type merger is presumed to have taken place. Sunyaev-Zel'dovich maps from MUSTANG indicate that a shock, with Mach number M = 1.0-2.9 and an extension of ˜200 kpc, sits near the centre of the cluster. The shock is also detected as a brightness and temperature discontinuity in X-ray observations. To search for diffuse radio emission associated with the merger, we have imaged the cluster with the LOw Frequency ARray (LOFAR) at 120-165 MHz. Our LOFAR radio images reveal previously undetected AGN emission, but do not show clear cluster-scale diffuse emission in the form of a radio relic nor a radio halo. The region of the shock is on the western edge of AGN lobe emission from the brightest cluster galaxy. Correlating the flux of known shock-induced radio relics versus their size, we find that the radio emission overlapping the shocked region in MACS J0744.9+3927 is likely of AGN origin. We argue against the presence of a relic caused by diffusive shock acceleration and suggest that the shock is too weak to accelerate electrons from the intracluster medium.

RELICS: Strong-lensing Analysis of the Massive Clusters MACS J0308.9+2645 and PLCK G171.9‑40.7

NASA Astrophysics Data System (ADS)

Acebron, Ana; Cibirka, Nathália; Zitrin, Adi; Coe, Dan; Agulli, Irene; Sharon, Keren; Bradač, Maruša; Frye, Brenda; Livermore, Rachael C.; Mahler, Guillaume; Salmon, Brett; Umetsu, Keiichi; Bradley, Larry; Andrade-Santos, Felipe; Avila, Roberto; Carrasco, Daniela; Cerny, Catherine; Czakon, Nicole G.; Dawson, William A.; Hoag, Austin T.; Huang, Kuang-Han; Johnson, Traci L.; Jones, Christine; Kikuchihara, Shotaro; Lam, Daniel; Lovisari, Lorenzo; Mainali, Ramesh; Oesch, Pascal A.; Ogaz, Sara; Ouchi, Masami; Past, Matthew; Paterno-Mahler, Rachel; Peterson, Avery; Ryan, Russell E.; Sendra-Server, Irene; Stark, Daniel P.; Strait, Victoria; Toft, Sune; Trenti, Michele; Vulcani, Benedetta

2018-05-01

Strong gravitational lensing by galaxy clusters has become a powerful tool for probing the high-redshift universe, magnifying distant and faint background galaxies. Reliable strong-lensing (SL) models are crucial for determining the intrinsic properties of distant, magnified sources and for constructing their luminosity function. We present here the first SL analysis of MACS J0308.9+2645 and PLCK G171.9‑40.7, two massive galaxy clusters imaged with the Hubble Space Telescope, in the framework of the Reionization Lensing Cluster Survey (RELICS). We use the light-traces-mass modeling technique to uncover sets of multiply imaged galaxies and constrain the mass distribution of the clusters. Our SL analysis reveals that both clusters have particularly large Einstein radii (θ E > 30″ for a source redshift of z s = 2), providing fairly large areas with high magnifications, useful for high-redshift galaxy searches (∼2 arcmin2 with μ > 5 to ∼1 arcmin2 with μ > 10, similar to a typical Hubble Frontier Fields cluster). We also find that MACS J0308.9+2645 hosts a promising, apparently bright (J ∼ 23.2–24.6 AB), multiply imaged high-redshift candidate at z ∼ 6.4. These images are among the brightest high-redshift candidates found in RELICS. Our mass models, including magnification maps, are made publicly available for the community through the Mikulski Archive for Space Telescopes.

Late decaying 2-component dark matter scenario as an explanation of the AMS-02 positron excess

DOE Office of Scientific and Technical Information (OSTI.GOV)

Buch, Jatan; Ralegankar, Pranjal; Rentala, Vikram, E-mail: jatan_buch@brown.edu, E-mail: pranjal6@illinois.edu, E-mail: rentala@phy.iitb.ac.in

The long standing anomaly in the positron flux as measured by the PAMELA and AMS-02 experiments could potentially be explained by dark matter (DM) annihilations. This scenario typically requires a large 'boost factor' to be consistent with a thermal relic dark matter candidate produced via freeze-out. However, such an explanation is disfavored by constraints from CMB observations on energy deposition during the epoch of recombination. We discuss a scenario called late-decaying two-component dark matter (LD2DM), where the entire DM consists of two semi-degenerate species. Within this framework, the heavier species is produced as a thermal relic in the early universemore » and decays to the lighter species over cosmological timescales. Consequently, the lighter species becomes the DM which populates the universe today. We show that annihilation of the lighter DM species with an enhanced cross-section, produced via such a non-thermal mechanism, can explain the observed AMS-02 positron flux while avoiding CMB constraints. The observed DM relic density can be correctly reproduced as well with simple s -wave annihilation cross-sections. We demonstrate that the scenario is safe from CMB constraints on late-time energy depositions during the cosmic 'dark ages'. Interestingly, structure formation constraints force us to consider small mass splittings between the two dark matter species. We explore possible cosmological and particle physics signatures in a toy model that realizes this scenario.« less

Geometric structures of super-(Diff(S/sup 1/)/S/sup 1/)*

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schmidke, W.B.; Vokos, S.P.

Superconformal invariance is of central importance to a perturbative and non-perturbative formulation of stringy theory. The group that describes the invariances of the superstring is the super-Virasoro group, Super-Diff(S/sup 1/). The super-reparameterizations of the circle that leave a point fixed compose the quotient space Super-(Diff(S/sup 1/)/S/sup 1/). We investigate the holomorphic geometry of this infinite-dimensional Kaehler supermanifold and calculate its curvature. copyright 1989 Academic Press, Inc.

Consequences of an Abelian family symmetry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ramond, P.

1996-01-01

The addition of an Abelian family symmetry to the Minimal Super-symmetric Standard Model reproduces the observed hierarchies of quark and lepton masses and quark mixing angles, only if it is anomalous. Green-Schwarz compensation of its anomalies requires the electroweak mixing angle to be sin{sup 2}{theta}{sub {omega}} = 3/8 at the string scale, without any assumed GUT structure, suggesting a superstring origin for the standard model. The analysis is extended to neutrino masses and the lepton mixing matrix.

Investigation of proposed process sequence for the array automated assembly task, phases 1 and 2

NASA Technical Reports Server (NTRS)

Mardesich, N.; Garcia, A.; Eskenas, K.

1980-01-01

Progress was made on the process sequence for module fabrication. A shift from bonding with a conformal coating to laminating with ethylene vinyl acetate and a glass superstrate is recommended for further module fabrication. The processes that were retained for the selected process sequence, spin-on diffusion, print and fire aluminum p+ back, clean, print and fire silver front contact and apply tin pad to aluminum back, were evaluated for their cost contribution.

RNA genetics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Domingo, E.; Holland, J.J.; Ahlquist, P.

1988-01-01

This book contains the proceedings on RNA genetics: RNA-directed virus replication Volume 1. Topics covered include: Replication of the poliovirus genome; Influenza viral RNA transcription and replication; and Relication of the reoviridal: Information derived from gene cloning and expression.

Supernova Relic Neutrinos and the Supernova Rate Problem: Analysis of Uncertainties and Detectability of ONeMg and Failed Supernovae

NASA Astrophysics Data System (ADS)

Mathews, Grant J.; Hidaka, Jun; Kajino, Toshitaka; Suzuki, Jyutaro

2014-08-01

Direct measurements of the core collapse supernova rate (R SN) in the redshift range 0 <= z <= 1 appear to be about a factor of two smaller than the rate inferred from the measured cosmic massive star formation rate (SFR). This discrepancy would imply that about one-half of the massive stars that have been born in the local observed comoving volume did not explode as luminous supernovae. In this work, we explore the possibility that one could clarify the source of this "supernova rate problem" by detecting the energy spectrum of supernova relic neutrinos with a next generation 106 ton water Čerenkov detector like Hyper-Kamiokande. First, we re-examine the supernova rate problem. We make a conservative alternative compilation of the measured SFR data over the redshift range 0 <=z <= 7. We show that by only including published SFR data for which the dust obscuration has been directly determined, the ratio of the observed massive SFR to the observed supernova rate R SN has large uncertainties {\\sim }1.8^{+1.6}_{-0.6} and is statistically consistent with no supernova rate problem. If we further consider that a significant fraction of massive stars will end their lives as faint ONeMg SNe or as failed SNe leading to a black hole remnant, then the ratio reduces to {\\sim }1.1^{+1.0}_{-0.4} and the rate problem is essentially solved. We next examine the prospects for detecting this solution to the supernova rate problem. We first study the sources of uncertainty involved in the theoretical estimates of the neutrino detection rate and analyze whether the spectrum of relic neutrinos can be used to independently identify the existence of a supernova rate problem and its source. We consider an ensemble of published and unpublished core collapse supernova simulation models to estimate the uncertainties in the anticipated neutrino luminosities and temperatures. We illustrate how the spectrum of detector events might be used to establish the average neutrino temperature and constrain SN models. We also consider supernova ν-process nucleosynthesis to deduce constraints on the temperature of the various neutrino flavors. We study the effects of neutrino oscillations on the detected neutrino energy spectrum and also show that one might distinguish the equation of state (EoS) as well as the cause of the possible missing luminous supernovae from the detection of supernova relic neutrinos. We also analyze a possible enhanced contribution from failed supernovae leading to a black hole remnant as a solution to the supernova rate problem. We conclude that indeed it might be possible (though difficult) to measure the neutrino temperature, neutrino oscillations, and the EoS and confirm this source of missing luminous supernovae by the detection of the spectrum of relic neutrinos.

Supernova relic neutrinos and the supernova rate problem: Analysis of uncertainties and detectability of ONeMg and failed supernovae

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mathews, Grant J.; Hidaka, Jun; Kajino, Toshitaka

2014-08-01

Direct measurements of the core collapse supernova rate (R{sub SN}) in the redshift range 0 ≤ z ≤ 1 appear to be about a factor of two smaller than the rate inferred from the measured cosmic massive star formation rate (SFR). This discrepancy would imply that about one-half of the massive stars that have been born in the local observed comoving volume did not explode as luminous supernovae. In this work, we explore the possibility that one could clarify the source of this 'supernova rate problem' by detecting the energy spectrum of supernova relic neutrinos with a next generation 10{supmore » 6} ton water Čerenkov detector like Hyper-Kamiokande. First, we re-examine the supernova rate problem. We make a conservative alternative compilation of the measured SFR data over the redshift range 0 ≤z ≤ 7. We show that by only including published SFR data for which the dust obscuration has been directly determined, the ratio of the observed massive SFR to the observed supernova rate R{sub SN} has large uncertainties ∼1.8{sub −0.6}{sup +1.6} and is statistically consistent with no supernova rate problem. If we further consider that a significant fraction of massive stars will end their lives as faint ONeMg SNe or as failed SNe leading to a black hole remnant, then the ratio reduces to ∼1.1{sub −0.4}{sup +1.0} and the rate problem is essentially solved. We next examine the prospects for detecting this solution to the supernova rate problem. We first study the sources of uncertainty involved in the theoretical estimates of the neutrino detection rate and analyze whether the spectrum of relic neutrinos can be used to independently identify the existence of a supernova rate problem and its source. We consider an ensemble of published and unpublished core collapse supernova simulation models to estimate the uncertainties in the anticipated neutrino luminosities and temperatures. We illustrate how the spectrum of detector events might be used to establish the average neutrino temperature and constrain SN models. We also consider supernova ν-process nucleosynthesis to deduce constraints on the temperature of the various neutrino flavors. We study the effects of neutrino oscillations on the detected neutrino energy spectrum and also show that one might distinguish the equation of state (EoS) as well as the cause of the possible missing luminous supernovae from the detection of supernova relic neutrinos. We also analyze a possible enhanced contribution from failed supernovae leading to a black hole remnant as a solution to the supernova rate problem. We conclude that indeed it might be possible (though difficult) to measure the neutrino temperature, neutrino oscillations, and the EoS and confirm this source of missing luminous supernovae by the detection of the spectrum of relic neutrinos.« less

Hypotheses of cancer weakening and origin.

PubMed

Chan, John Cheung Yuen

2015-01-01

Approximately 2.7 billion years ago, cyanobacteria began producing oxygen by photosynthesis. Any free oxygen they produced was chemically captured by dissolved iron or organic matter. There was no ozone layer to protect living species against the radiation from space. Eukaryotic cells lived in water, under hypoxic environments, and metabolized glucose by fermentation. The Great Oxygenation Event (GOE) describes the point when oxygen sinks became saturated. This massive oxygenation of the Earth occurred approximately half a billion years ago. Species that evolved after the GOE are characterized by aerobic metabolism. Mammals evolved approximately a few hundred million years ago, with the ancient eukaryotic genes deeply embedded in their genome. Many genes have been exchanged by horizontal gene transfer (HGT) throughout the history of cellular evolution. Mammals have been invaded by viruses, and while viral genetic relics are embedded in mammalian junk genes, not all junk genes are genetic relics of viruses. These viral relics have been inactivated through evolution and have little impact on mammalian life. However, there is evidence to suggest that these viral genetic relics are linked to cancer. This hypothesis states that cancer develops when cell reproduction becomes defective because of the active involvement of viral genes, in a process similar to genetic engineering. Cancer cells are amalgamations of genetically modified organisms (GMOs). There are two main groups in cancer development. One group of cells arises by genetic engineering of a viral genetic relic, such as endogenous retroviruses (ERVs), which evolved after oxygenation of the atmosphere. This group is referred to here as genetically modified organisms from viral genes (GMOV). GMOVs may be inhibited by anticancer drugs. The second group arises by engineering of the genes of ancient eukaryotes, which existed prior to the oxygenation of the Earth. This second group is referred to as genetically modified organisms from ancient eukaryotic genes (GMOE). The GMOE group lives in hypoxic environments and metabolizes glucose by fermentation. GMOEs represent advanced cancer, which proliferate aggressively and are resistant to DNA damage. It has been demonstrated that as an ERV becomes more prevalent in a mammalian genome, the possibility that the mammal will develop cancer increases. The hypothesis also states that most cancers have their origins in GMOV by the incorporation of viral genes from junk genes. As the cancer progresses, further subgroups of cancer GMOs will develop. If the cancer advances even further, the GMOE could eventually develop prior to late-stage cancer. Because the genes of ancient eukaryotes have enhanced innate immunity, GMOE will eventually prevail over the weaker GMOV during cancer subgroup competition. Hence, cancer development is mainly determined by genes in the mammalian genome. An inherent weakness of cancer cells is their dependence on glucose and iron. Furthermore, they cannot tolerate physical disturbance. Ancient gene GMOs can be treated with a combination of mechanical vibration using glucose-coated magnetic nanoparticles and strengthening of the immune system. Herein, I suggest trials for verifying this hypothesis.

Hypotheses of Cancer Weakening and Origin

PubMed Central

CHAN, John Cheung Yuen

2015-01-01

Approximately 2.7 billion years ago, cyanobacteria began producing oxygen by photosynthesis. Any free oxygen they produced was chemically captured by dissolved iron or organic matter. There was no ozone layer to protect living species against the radiation from space. Eukaryotic cells lived in water, under hypoxic environments, and metabolized glucose by fermentation. The Great Oxygenation Event (GOE) describes the point when oxygen sinks became saturated. This massive oxygenation of the Earth occurred approximately half a billion years ago. Species that evolved after the GOE are characterized by aerobic metabolism. Mammals evolved approximately a few hundred million years ago, with the ancient eukaryotic genes deeply embedded in their genome. Many genes have been exchanged by horizontal gene transfer (HGT) throughout the history of cellular evolution. Mammals have been invaded by viruses, and while viral genetic relics are embedded in mammalian junk genes, not all junk genes are genetic relics of viruses. These viral relics have been inactivated through evolution and have little impact on mammalian life. However, there is evidence to suggest that these viral genetic relics are linked to cancer. This hypothesis states that cancer develops when cell reproduction becomes defective because of the active involvement of viral genes, in a process similar to genetic engineering. Cancer cells are amalgamations of genetically modified organisms (GMOs). There are two main groups in cancer development. One group of cells arises by genetic engineering of a viral genetic relic, such as endogenous retroviruses (ERVs), which evolved after oxygenation of the atmosphere. This group is referred to here as genetically modified organisms from viral genes (GMOV). GMOVs may be inhibited by anticancer drugs. The second group arises by engineering of the genes of ancient eukaryotes, which existed prior to the oxygenation of the Earth. This second group is referred to as genetically modified organisms from ancient eukaryotic genes (GMOE). The GMOE group lives in hypoxic environments and metabolizes glucose by fermentation. GMOEs represent advanced cancer, which proliferate aggressively and are resistant to DNA damage. It has been demonstrated that as an ERV becomes more prevalent in a mammalian genome, the possibility that the mammal will develop cancer increases. The hypothesis also states that most cancers have their origins in GMOV by the incorporation of viral genes from junk genes. As the cancer progresses, further subgroups of cancer GMOs will develop. If the cancer advances even further, the GMOE could eventually develop prior to late-stage cancer. Because the genes of ancient eukaryotes have enhanced innate immunity, GMOE will eventually prevail over the weaker GMOV during cancer subgroup competition. Hence, cancer development is mainly determined by genes in the mammalian genome. An inherent weakness of cancer cells is their dependence on glucose and iron. Furthermore, they cannot tolerate physical disturbance. Ancient gene GMOs can be treated with a combination of mechanical vibration using glucose-coated magnetic nanoparticles and strengthening of the immune system. Herein, I suggest trials for verifying this hypothesis. PMID:25874009

Naturally light Dirac neutrino in Left-Right Symmetric Model

DOE Office of Scientific and Technical Information (OSTI.GOV)

Borah, Debasish; Dasgupta, Arnab, E-mail: dborah@iitg.ernet.in, E-mail: arnab.d@iopb.res.in

We study the possibility of generating tiny Dirac masses of neutrinos in Left-Right Symmetric Model (LRSM) without requiring the existence of any additional symmetries. The charged fermions acquire masses through a universal seesaw mechanism due to the presence of additional vector like fermions. The neutrinos acquire a one-loop Dirac mass from the same additional vector like charged leptons without requiring any additional discrete symmetries. The model can also be extended by an additional Z {sub 2} symmetry in order to have a scotogenic version of this scenario predicting a stable dark matter candidate. We show that the latest Planck uppermore » bound on the effective number of relativistic degrees of freedom N {sub eff}=3.15 ± 0.23 tightly constrains the right sector gauge boson masses to be heavier than 3.548 TeV . This bound on gauge boson mass also affects the allowed values of right scalar doublet dark matter mass from the requirement of satisfying the Planck bound on dark matter relic abundance. We also discuss the possible implications of such a scenario in charged lepton flavour violation and generating observable electric dipole moment of leptons.« less

Gravitational clustering in the expanding universe - Controlled high-resolution studies in two dimensions

NASA Technical Reports Server (NTRS)

Beacom, John Francis; Dominik, Kurt G.; Melott, Adrian L.; Perkins, Sam P.; Shandarin, Sergei F.

1991-01-01

Results are presented from a series of gravitational clustering simulations in two dimensions. These simulations are a significant departure from previous work, since in two dimensions one can have large dynamic range in both length scale and mass using present computer technology. Controlled experiments were conducted by varying the slope of power-law initial density fluctuation spectra and varying cutoffs at large k, while holding constant the phases of individual Fourier components and the scale of nonlinearity. Filaments are found in many different simulations, even with pure power-law initial conditions. By direct comparison, filaments, called 'second-generation pancakes' are shown to arise as a consequence of mild nonlinearity on scales much larger than the correlation length and are not relics of an initial lattice or due to sparse sampling of the Fourier components. Bumps of low amplitude in the two-point correlation are found to be generic but usually only statistical fluctuations. Power spectra are much easier to relate to initial conditions, and seem to follow a simple triangular shape (on log-log plot) in the nonlinear regime. The rms density fluctuation with Gaussian smoothing is the most stable indicator of nonlinearity.

Right-handed neutrino dark matter in left-right symmetric models

NASA Astrophysics Data System (ADS)

Bhupal Dev, P. S.; Mohapatra, Rabindra N.; Zhang, Yongchao

2017-07-01

We show that in a class of non-supersymmetric left-right extensions of the Standard Model (SM), the lightest right-handed neutrino (RHN) is naturally stable and can therefore play the role of thermal Dark Matter (DM) in the Universe for a wide mass range from TeV to PeV. Our model is based on the gauge group SU(3) c × SU(2) L × SU(2) R × U(1) YL × U(1) YR in which a heavy copy of the SM fermions are introduced and the stability of the RHN DM is guaranteed by an automatic Z 2 symmetry present in the leptonic sector. The active neutrino masses in the model arise from the type-II seesaw mechanism. We find a lower bound on the RHN DM mass of order TeV from relic density constraints, as well as an unitarity upper bound in the multi-TeV to PeV scale, depending on the entropy dilution factor. The RHN DM could be made long-lived by soft-breaking of the Z 2 symmetry and provides a concrete example of decaying DM interpretation of the PeV neutrinos observed at IceCube.

A Molecular Vestige of the Origin of Life on Minerals: Phosphorybosyl-Disphosphate

NASA Astrophysics Data System (ADS)

Akouche, M.; Jaber, M.; Maurel, M.-C.; Lambert, J.-F.; Georgelin, T.

2017-07-01

Nucleotides were synthesized from Ribose, Adenine, and phosphates on silica surfaces in one pot process. A important molecular intermediate was enlightened, the phosphoribosyl pyrophosphate. This molecule is a molecular relic of early earth.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Arcadi, Giorgio; Ghosh, Pradipta; Centre de Physique Théorique, Ecole polytechnique, CNRS, Université Paris-Saclay, 91128 Palaiseau Cedex

We investigate a simple setup in which an excess in the di-photon invariant mass distribution around 750 GeV, as seen by the ATLAS and CMS collaborations, is originated through a pair of collimated photon pairs. In this framework a scalar state s decays into two light pseudo-Goldstone bosons a, each of which subsequently decays into a pair of collimated photons which are misidentified as a single photon. In a minimal context of spontaneous symmetry breaking, we show that coupling a complex scalar field Φ=(s+ia)/√2 to a fermionic dark matter candidate χ, also responsible for generating its mass, allows for themore » correct relic density in a large region of the parameter space, while not being excluded by the direct or indirect detection experiments. Moreover, the correct relic abundance can naturally co-exist with a relatively large width for the resonant field s.« less

Little composite dark matter.

PubMed

Balkin, Reuven; Perez, Gilad; Weiler, Andreas

2018-01-01

We examine the dark matter phenomenology of a composite electroweak singlet state. This singlet belongs to the Goldstone sector of a well-motivated extension of the Littlest Higgs with T -parity. A viable parameter space, consistent with the observed dark matter relic abundance as well as with the various collider, electroweak precision and dark matter direct detection experimental constraints is found for this scenario. T -parity implies a rich LHC phenomenology, which forms an interesting interplay between conventional natural SUSY type of signals involving third generation quarks and missing energy, from stop-like particle production and decay, and composite Higgs type of signals involving third generation quarks associated with Higgs and electroweak gauge boson, from vector-like top-partners production and decay. The composite features of the dark matter phenomenology allows the composite singlet to produce the correct relic abundance while interacting weakly with the Higgs via the usual Higgs portal coupling [Formula: see text], thus evading direct detection.

Non Thermal Emission from Clusters of Galaxies: the Importance of a Joint LOFAR/Simbol-X View

NASA Astrophysics Data System (ADS)

Ferrari, C.

2009-05-01

Deep radio observations of galaxy clusters have revealed the existence of diffuse radio sources (``halos'' and ``relics'') related to the presence of relativistic electrons and weak magnetic fields in the intracluster volume. I will outline our current knowledge about the presence and properties of this non-thermal cluster component. Despite the recent progress made in observational and theoretical studies of the non-thermal emission in galaxy clusters, a number of open questions about its origin and its effects on the thermo-dynamical evolution of galaxy clusters need to be answered. I will show the importance of combining galaxy cluster observations by new-generation instruments such as LOFAR and Simbol-X. A deeper knowledge of the non-thermal cluster component, together with statistical studies of radio halos and relics, will allow to test the current cluster formation scenario and to better constrain the physics of large scale structure evolution.

Little composite dark matter

NASA Astrophysics Data System (ADS)

Balkin, Reuven; Perez, Gilad; Weiler, Andreas

2018-02-01

We examine the dark matter phenomenology of a composite electroweak singlet state. This singlet belongs to the Goldstone sector of a well-motivated extension of the Littlest Higgs with T-parity. A viable parameter space, consistent with the observed dark matter relic abundance as well as with the various collider, electroweak precision and dark matter direct detection experimental constraints is found for this scenario. T-parity implies a rich LHC phenomenology, which forms an interesting interplay between conventional natural SUSY type of signals involving third generation quarks and missing energy, from stop-like particle production and decay, and composite Higgs type of signals involving third generation quarks associated with Higgs and electroweak gauge boson, from vector-like top-partners production and decay. The composite features of the dark matter phenomenology allows the composite singlet to produce the correct relic abundance while interacting weakly with the Higgs via the usual Higgs portal coupling λ _{ {DM}}˜ O(1%), thus evading direct detection.

Semi-inclusive wino and higgsino annihilation to LL'

DOE PAGES

Baumgart, Matthew; Vaidya, Varun

2016-03-31

Here, we systematically compute the annihilation rate for winos and higgsinos into the final state relevant for indirect detection experiments, γ + X. The radiative corrections to this process receive enhancement from the large Bloch-Nordsieck-Violating Sudakov logarithm, log(2Mmore » $${\\chi }$$/M W). We resum the double logs and include single logs to fixed order using a formalism that combines nonrelativistic and soft-collinear effective field theories. For the wino case, we update an earlier exclusion adapting results of the HESS experiment. At the thermal relic mass of 3 TeV, LL' corrections result in a ~30% reduction in rate relative to LL. But, single logs do not save the wino, and it is still excluded by an order of magnitude. Finally, experimental cuts produce an endpoint region which, our results show, significantly effects the higgsino rate at its thermal-relic mass near 1 TeV and is deserving of further study.« less

Singlet-triplet fermionic dark matter and LHC phenomenology

NASA Astrophysics Data System (ADS)

Choubey, Sandhya; Khan, Sarif; Mitra, Manimala; Mondal, Subhadeep

2018-04-01

It is well known that for the pure standard model triplet fermionic WIMP-type dark matter (DM), the relic density is satisfied around 2 TeV. For such a heavy mass particle, the production cross-section at 13 TeV run of LHC will be very small. Extending the model further with a singlet fermion and a triplet scalar, DM relic density can be satisfied for even much lower masses. The lower mass DM can be copiously produced at LHC and hence the model can be tested at collider. For the present model we have studied the multi jet (≥ 2 j) + missing energy ([InlineEquation not available: see fulltext.]) signal and show that this can be detected in the near future of the LHC 13 TeV run. We also predict that the present model is testable by the earth based DM direct detection experiments like Xenon-1T and in future by Darwin.

PeV-scale dark matter as a thermal relic of a decoupled sector

DOE PAGES

Berlin, Asher; Hooper, Dan; Krnjaic, Gordan

2016-06-21

We consider a class of scenarios in which the dark matter is part of a heavy hidden sector that is thermally decoupled from the Standard Model in the early universe. The dark matter freezes-out by annihilating to a lighter, metastable state, whose subsequent abundance can naturally come to dominate the energy density of the universe. Moreover, when this state decays, it reheats the visible sector and dilutes all relic abundances, thereby allowing the dark matter to be orders of magnitude heavier than the weak scale. For concreteness, we consider a simple realization with a Dirac fermion dark matter candidate coupledmore » to a massive gauge boson that decays to the Standard Model through its kinetic mixing with hypercharge. Finally, we identify viable parameter space in which the dark matter can be as heavy as ~1-100 PeV without being overproduced in the early universe.« less

RELICS: Strong Lens Models for Five Galaxy Clusters from the Reionization Lensing Cluster Survey

NASA Astrophysics Data System (ADS)

Cerny, Catherine; Sharon, Keren; Andrade-Santos, Felipe; Avila, Roberto J.; Bradač, Maruša; Bradley, Larry D.; Carrasco, Daniela; Coe, Dan; Czakon, Nicole G.; Dawson, William A.; Frye, Brenda L.; Hoag, Austin; Huang, Kuang-Han; Johnson, Traci L.; Jones, Christine; Lam, Daniel; Lovisari, Lorenzo; Mainali, Ramesh; Oesch, Pascal A.; Ogaz, Sara; Past, Matthew; Paterno-Mahler, Rachel; Peterson, Avery; Riess, Adam G.; Rodney, Steven A.; Ryan, Russell E.; Salmon, Brett; Sendra-Server, Irene; Stark, Daniel P.; Strolger, Louis-Gregory; Trenti, Michele; Umetsu, Keiichi; Vulcani, Benedetta; Zitrin, Adi

2018-06-01

Strong gravitational lensing by galaxy clusters magnifies background galaxies, enhancing our ability to discover statistically significant samples of galaxies at {\\boldsymbol{z}}> 6, in order to constrain the high-redshift galaxy luminosity functions. Here, we present the first five lens models out of the Reionization Lensing Cluster Survey (RELICS) Hubble Treasury Program, based on new HST WFC3/IR and ACS imaging of the clusters RXC J0142.9+4438, Abell 2537, Abell 2163, RXC J2211.7–0349, and ACT-CLJ0102–49151. The derived lensing magnification is essential for estimating the intrinsic properties of high-redshift galaxy candidates, and properly accounting for the survey volume. We report on new spectroscopic redshifts of multiply imaged lensed galaxies behind these clusters, which are used as constraints, and detail our strategy to reduce systematic uncertainties due to lack of spectroscopic information. In addition, we quantify the uncertainty on the lensing magnification due to statistical and systematic errors related to the lens modeling process, and find that in all but one cluster, the magnification is constrained to better than 20% in at least 80% of the field of view, including statistical and systematic uncertainties. The five clusters presented in this paper span the range of masses and redshifts of the clusters in the RELICS program. We find that they exhibit similar strong lensing efficiencies to the clusters targeted by the Hubble Frontier Fields within the WFC3/IR field of view. Outputs of the lens models are made available to the community through the Mikulski Archive for Space Telescopes.

Dark Energy and Dark Matter Phenomena and the Universe with Variable Gravitational Mass

NASA Astrophysics Data System (ADS)

Gorkavyi, N.

2005-12-01

Generation of high-frequency gravitational waves near the singularity is a crucial factor for understanding the origin and dynamics of the Universe. Emission of gravitational waves increases with a decreasing radius of collapsed object much faster than a gravitational force itself. Gravitationally unstable matter of the Universe will be completely converted into gravitational radiation during the Big Crunch. According to Misner, Thorne & Wheeler (Gravitation, 1977, p.959) plane gravitational waves have not gravitational mass or spacetime is flat everywhere outside the pulse. We can propose that the gravitational mass of the Universe is vanished after converting matter into gravitational waves. This hypothesis in the framework of Einstein's theory of gravitation can solve the problem of singularity without contradiction with theorems by Penrose-Hawking; explain the acceleration of our Universe as the effect of a retarded gravitational potential (Gorkavyi, BAAS, 2003, 35, #3) and the low quadrupole in fluctuations in CMB as result of blue-shift effect in a gravitational field. Proposed solution of dark energy problem free from coincidence problems. The hypothesis keeps best parts of Big Bang theory and inflation model without any unknown physical fields or new dimensions. According to this hypothesis a relic sea of high-frequency gravitational radiation in our Universe can be very dense. Interaction of relic gravitational waves with gravitational fields of galaxies and stars can create an additional dynamical effects like pressure of relic radiation that proportional to gravitational potential GM/(Rc2). This effect can be responsible for dark matter phenomena in galaxies and the Pioneer acceleration in the solar system (Gorkavyi, BAAS, 2005, 37, #2).

The Efficiency of Magnetic Field Amplification at Shocks by Turbulence

NASA Technical Reports Server (NTRS)

Ji, Suoqing; Oh, S. Peng; Ruszkowsi, M.; Markevitch, M.

2016-01-01

Turbulent dynamo field amplification has often been invoked to explain the strong field strengths in thin rims in supernova shocks (approx.100 micrograms) and in radio relics in galaxy clusters (approx. micrograms). We present high-resolution magnetohydrodynamic simulations of the interaction between pre-shock turbulence, clumping and shocks, to quantify the conditions under which turbulent dynamo amplification can be significant. We demonstrate numerically converged field amplification which scales with Alfven Mach number, B/B0 varies as MA, up to MA approx.150.This implies that the post-shock field strength is relatively independent of the seed field. Amplification is dominated by compression at low MA, and stretching (turbulent amplification) at high MA. For high MA, the B-field grows exponentially and saturates at equipartition with turbulence, while the vorticity jumps sharply at the shock and subsequently decays; the resulting field is orientated predominately along the shock normal (an effect only apparent in 3D and not 2D). This agrees with the radial field bias seen in supernova remnants. By contrast, for low MA, field amplification is mostly compressional, relatively modest, and results in a predominantly perpendicular field. The latter is consistent with the polarization seen in radio relics. Our results are relatively robust to the assumed level of gas clumping. Our results imply that the turbulent dynamo may be important for supernovae, but is only consistent with the field strength, and not geometry, for cluster radio relics. For the latter, this implies strong pre-existing B-fields in the ambient cluster outskirts.

The Application of Regulating Plant Growth into Protective Engineering of The Western Mansions Area in The Old Summer Palace

NASA Astrophysics Data System (ADS)

Cong, W.; Song, Y.

2015-08-01

The Western Mansions (Xīyáng Lóu) in the Old Summer Palace (Yuánmíngyuán ) are extremely valuable set of heritage. When it was first conceived and constructed, it was an important part of the successful exchange between Chinese and the Western cultures. It marked the entry of European architecture and the art of gardening into Chinese royal gardens. Therefore, the Western Mansions occupies a vital position in the garden history of China and even the world. Since the 1980s, the Administrative Office of the Old Summer Place (Yuánmíngyuán) had cleared and reorganized the Western Mansions relics. But currently, both the protection and display of the Western Mansions are far from satisfactory. With regards to the outlook of the cultural relics, there is cracking and collapses, relics are damaged by tourists, there is rainwater erosion, plant aggression, pollutants, weathering, crumbling and other threats. This is caused by the improper protective measures and the yearslong erosion through natural causes. Therefore, in order to protect the important heritage and show people the situation of the plant growth. As the basis of the copper planting, the historical conditions of planting can be speculated at the time of the western building, which become an important basis for the recovery of history. This paper also further researches on the informationg of plant form in history,to avoid destabilising the heritage.Some destruction from plant growth can be controled.

Archeointensity estimates of a tenth-century kiln: first application of the Tsunakawa-Shaw paleointensity method to archeological relics

NASA Astrophysics Data System (ADS)

Kitahara, Yu; Yamamoto, Yuhji; Ohno, Masao; Kuwahara, Yoshihiro; Kameda, Shuichi; Hatakeyama, Tadahiro

2018-05-01

Paleomagnetic information reconstructed from archeological materials can be utilized to estimate the archeological age of excavated relics, in addition to revealing the geomagnetic secular variation and core dynamics. The direction and intensity of the Earth's magnetic field (archeodirection and archeointensity) can be ascertained using different methods, many of which have been proposed over the past decade. Among the new experimental techniques for archeointensity estimates is the Tsunakawa-Shaw method. This study demonstrates the validity of the Tsunakawa-Shaw method to reconstruct archeointensity from samples of baked clay from archeological relics. The validity of the approach was tested by comparison with the IZZI-Thellier method. The intensity values obtained coincided at the standard deviation (1 σ) level. A total of 8 specimens for the Tsunakawa-Shaw method and 16 specimens for the IZZI-Thellier method, from 8 baked clay blocks, collected from the surface of the kiln were used in these experiments. Among them, 8 specimens (for the Tsunakawa-Shaw method) and 3 specimens (for the IZZI-Thellier method) passed a set of strict selection criteria used in the final evaluation of validity. Additionally, we performed rock magnetic experiments, mineral analysis, and paleodirection measurement to evaluate the suitability of the baked clay samples for paleointensity experiments and hence confirmed that the sample properties were ideal for performing paleointensity experiments. It is notable that the newly estimated archaomagnetic intensity values are lower than those in previous studies that used other paleointensity methods for the tenth century in Japan. [Figure not available: see fulltext.

The puzzle of high heads beneath the West Cumbrian coast, UK: a possible solution

NASA Astrophysics Data System (ADS)

Black, John H.; Barker, John A.

2016-03-01

A region of high heads within the Borrowdale Volcanic Group (BVG; a fractured crystalline rock) beneath the coastal plain of West Cumbria, England (UK), is identified as a possible relic left over by the Late Devensian ice sheet. It was found during investigations in the 1990s. Contemporary modelling work failed to produce a satisfactory explanation of the high heads compatible with the `cold recharge' isotopic signature of the groundwater. This study has reassessed the original hydraulic testing results. By plotting density-adjusted heads versus their depth below the water table in the immediate vicinity of the borehole in which they were measured, a depth profile resembling a `wave' was revealed with a peak value located at 1,100 m depth. The possibility that this wave represents relic heads from the last major ice sheet has been assessed using one-dimensional mathematical analysis based on a poroelastic approach. It is found that a wet-based ice sheet above the West Cumbrian coast was probably thick enough and sufficiently long-lasting to leave such relic heads providing that the hydraulic diffusivity of the BVG is in the order of 10-6 m s-1. Initial assessment 20 years ago of the long-interval slug tests suggested that such low values are not likely. More recent interpretation argues for such low values of hydraulic diffusivity. It is concluded that ice sheet recharge is the most likely cause of the raised heads, that the BVG contains significant patches of very low conductivity rock, and that long-interval single-hole tests should be avoided in fractured crystalline rock.

FIMP dark matter freeze-in gauge mediation and hidden sector

NASA Astrophysics Data System (ADS)

Tsao, Kuo-Hsing

2018-07-01

We explore the dark matter freeze-in mechanism within the gauge mediation framework, which involves a hidden feebly interacting massive particle (FIMP) coupling feebly with the messenger fields while the messengers are still in the thermal bath. The FIMP is the fermionic component of the pseudo-moduli in a generic metastable supersymmetry (SUSY) breaking model and resides in the hidden sector. The relic abundance and the mass of the FIMP are determined by the SUSY breaking scale and the feeble coupling. The gravitino, which is the canonical dark matter candidate in the gauge mediation framework, contributes to the dark matter relic abundance along with the freeze-in of the FIMP. The hidden sector thus becomes two-component with both the FIMP and gravitino lodging in the SUSY breaking hidden sector. We point out that the ratio between the FIMP and the gravitino is determined by how SUSY breaking is communicated to the messengers. In particular when the FIMP dominates the hidden sector, the gravitino becomes the minor contributor in the hidden sector. Meanwhile, the neutralino is assumed to be both the weakly interacting massive particle dark matter candidate in the freeze-out mechanism and the lightest observable SUSY particle. We further find out the neutralino has the sub-leading contribution to the current dark matter relic density in the parameter space of our freeze-in gauge mediation model. Our result links the SUSY breaking scale in the gauge mediation framework with the FIMP freeze-in production rate leading to a natural and predicting scenario for the studies of the dark matter in the hidden sector.

27 CFR 478.93 - Authorized operations by a licensed collector.

Code of Federal Regulations, 2011 CFR

2011-04-01

... the licensed collector in curios and relics. The collector's license is of no force or effect and a... disposition as required by § 478.125 (a) and (b). [T.D. ATF-270, 53 FR 10496, Mar. 31, 1988] ...

27 CFR 478.93 - Authorized operations by a licensed collector.

Code of Federal Regulations, 2010 CFR

2010-04-01

... the licensed collector in curios and relics. The collector's license is of no force or effect and a... disposition as required by § 478.125 (a) and (b). [T.D. ATF-270, 53 FR 10496, Mar. 31, 1988] ...

A class of exact classical solutions to string theory.

PubMed

Coley, A A

2002-12-31

We show that the recently obtained class of spacetimes for which all of the scalar curvature invariants vanish (which can be regarded as generalizations of pp-wave spacetimes) are exact solutions in string theory to all perturbative orders in the string tension scale. As a result the spectrum of the theory can be explicitly obtained, and these spacetimes are expected to provide some hints for the study of superstrings on more general backgrounds. Since these Lorentzian spacetimes suffer no quantum corrections to all loop orders they may also offer insights into quantum gravity.

Matrix theory interpretation of discrete light cone quantization string worldsheets

PubMed

Grignani; Orland; Paniak; Semenoff

2000-10-16

We study the null compactification of type-IIA string perturbation theory at finite temperature. We prove a theorem about Riemann surfaces establishing that the moduli spaces of infinite-momentum-frame superstring worldsheets are identical to those of branched-cover instantons in the matrix-string model conjectured to describe M theory. This means that the identification of string degrees of freedom in the matrix model proposed by Dijkgraaf, Verlinde, and Verlinde is correct and that its natural generalization produces the moduli space of Riemann surfaces at all orders in the genus expansion.

Exploring the Invisible Universe: From Black Holes to Superstrings

NASA Astrophysics Data System (ADS)

Baaquie, Belal E.; Willeboordse, Frederick H.

2015-03-01

The book is written for a broad scientific audience with an interest in the leading theories about the Universe. The focus is on the physical Universe, and the laws of Physics are taken to be the guiding light in all our analysis. Starting from first principles and using self-evident reasoning, all the fundamental ideas that are employed in exploring the hidden and invisible realms of the Universe are shown to arise quite naturally, once one adopts the outlook that has come to light with the advances in Physics...

Cosmological backgrounds of gravitational waves and eLISA/NGO: phase transitions, cosmic strings and other sources

DOE Office of Scientific and Technical Information (OSTI.GOV)

Binétruy, Pierre; Dufaux, Jean-François; Bohé, Alejandro

We review several cosmological backgrounds of gravitational waves accessible to direct-detection experiments, with a special emphasis on those backgrounds due to first-order phase transitions and networks of cosmic (super-)strings. For these two particular sources, we revisit in detail the computation of the gravitational wave background and improve the results of previous works in the literature. We apply our results to identify the scientific potential of the NGO/eLISA mission of ESA regarding the detectability of cosmological backgrounds.

Planar metamaterial based on hybridization for directive emission.

PubMed

Ourir, Abdelwaheb; Abdeddaim, Redha; de Rosny, Julien

2012-07-30

We present the first experimental demonstration of a high-directivity using a mu and epsilon near zero (MENZ) metamaterial. We use the hybridization principles to design a planar MENZ structure based on the fishnet unit cell. Resonant mode engineering achieves an effective permittivity and permeability that approaches zeros around 10.5 GHz simultaneously. We use this metamaterial as a superstrate of a microstrip patch antenna. We show that the directivity of the antenna is effectively enhanced compared to that of the patch antenna alone at the desired frequency.

High sensitivity optical biosensor based on polymer materials and using the Vernier effect.

PubMed

Azuelos, Paul; Girault, Pauline; Lorrain, Nathalie; Poffo, Luiz; Guendouz, Mohammed; Thual, Monique; Lemaître, Jonathan; Pirasteh, Parastesh; Hardy, Isabelle; Charrier, Joël

2017-11-27

We demonstrate the fabrication of a Vernier effect SU8/PMATRIFE polymer optical biosensor with high homogeneous sensitivity using a standard photolithography process. The sensor is based on one micro-resonator embedded on each arm of a Mach-Zehnder interferometer. Measurements are based on the refractive index variation of the optical waveguide superstrate with different concentrations of glucose solutions. The sensitivity of the sensor has been measured as 17558 nm/RIU and the limit of detection has been estimated to 1.1.10 -6 RIU.

Basic Research in Electronics (JSEP) Joint Services Electronics Program.

DTIC Science & Technology

1987-12-31

poiNU362Z~ fi5v WALu i~n v.j WSW)F fulmB JELECTROUICS FROMM. (U) POLYTECHNIC UII FAW1406lL WY MEKR RESERCH INST At A OLINEN ET ft. 31 DEC S? UmC...range, as discussed in section 3. The fifth topic relates to a superstrate-substrate structure that permits a simple printed-circuit antenna to radiate...Antennas Loaded by Periodic Metal Strips. In last year’s Annual Report we presented a simple and accurate transverse equivalent network for the class

Extra Dimensions of Space: Are They Going to be Found Soon?

ScienceCinema

Rubakov, Valery [Institute for Nuclear Research, Moscow, Russia

2017-12-09

Our space may well have more than 3 dimensions. Indeed, theories that pretend to be most fundamental choose to live in higher dimensions: a natural area for superstring/Mtheory is 9- or 10-dimensional space. Extra dimensions have been hidden so far, but they would open up above a certain energy threshold. A fascinating possibility is that this happens within reach of particle colliders. This lecture will address the motivation for such a viewpoint and implications of accessible extra dimensions for our understanding of nature.

Hubble Finds an Hourglass Nebula around a Dying Star

NASA Image and Video Library

1996-01-16

This Hubble telescope snapshot of MyCn18, a young planetary nebula, reveals that the object has an hourglass shape with an intricate pattern of etchings in its walls. A planetary nebula is the glowing relic of a dying, Sun-like star.

Compound-Specific Carbon Isotope Compositions of Aldehydes and Ketones in the Tagish Lake Meteorite

NASA Astrophysics Data System (ADS)

Simkus, D. N.; Aponte, J. C.; Hilts, R. W.; Elsila, J. E.; Herd, C. D. K.

2016-08-01

Aldehydes and ketones detected in the Tagish Lake meteorite are highly depleted in 13C, indicating that they are unlikely relic Strecker synthesis precursors. Potential sources for these compounds and the effects of aqueous alteration are discussed.

The differentiation process of the I-type granitoids in southwest Japan and New South Wares in Australia

NASA Astrophysics Data System (ADS)

Kawakatsu, K.; Iwamoto, Y.; Ebisu, S.; Hasegawa, M.; Hiraiwa, N.; Kawakatsu, T.; Kitano, A.; Masuta, T.; Ootsubo, H.; Wakazono, R.

2013-12-01

Cretaceous-Paleogene Granitoids in the inner zone of southwest Japan have been divided into two series: the magnetite series that is distributed mainly in the San-in belt and the ilmenite series that is distributed mainly in San-yo belt. For 8 years, we have been investigating the two series to clear their processes of magmatic differentiation. Recently, we discovered oscillatory zoned structure, exsolution lamellae of amphibole, and relics of pyroxene left in the core of amphibole from Harima granodiorite, Nunobiki granodiorite (San-yo belt) and Daito-Yokota quartz diorite (San-in belt). The amphibole that has microstructure coexists with magnetite, ilmenite and pyrrhotite. We compared the two series for crystallization and re-equilibrium by ion substitution using the microstructure of the amphibole as 'time measure' during the differentitation process of acidic magma. While magnetites and ilmenites coexist with the core of the amphiboles, the oxygen fugacity of the San-yo belt magma was low until the later stage of magmatic differentiation where H2S from the Earth's crust mixed with it. In the subsolidus process, hydrothermal solutions circulated. On the other hand, the oxygen fugacity of the San-in belt magma began to rise in the early stage of magmatic differentiation. In the later stage, mafic magma was contaminated with SO2. The rims of amphiboles coexist with pyrrhotites in both of belts. Furthermore, the re-equilibrium of minerals underwent progressive oxidation and hydrothermal fluid circulated actively in the subsolidus process. Bingie Bingie Point at New South Wares (Eurobodalla National Park) is a peninsula about a meter around. The plutonic rocks were formed in the Devonian period and belong to the magnetite series. They are classified I-type granitoids such as those found in the inner zone of southwest Japan. They have only trace amounts of oxide minerals and pyrrhotite. The amphiboles of the granitoids have oscillatory zoned structures at pale green rims. The structures are formed by the fluid circulations of intruded granodiorite magma. The relic pyroxene is left in the core of amphibole. These minerals were crystallized under stable conditions and the microstructures were developed in the amphiboles under the subsolidus conditions. These researches contribute to clarifying magmatic differentiation and are the foundation of understanding the exchange of substances in magmatic activity.

(N)LSP decays and gravitino dark matter relic abundance in big divisor (nearly) SLagy D3/D7μ-split SUSY

NASA Astrophysics Data System (ADS)

Dhuria, Mansi; Misra, Aalok

2013-02-01

Using the (nearly) Ricci-flat Swiss-Cheese metric of Misra (2012) [1], in the context of a mobile space-time filling D3-brane restricted to a nearly special Lagrangian sub-manifold (in the large volume limit, the pull-back of the Kähler form close to zero and the real part of the pull-back of e, θ=π/2 times the nowhere-vanishing holomorphic three-form providing the volume form on the three-cycle) of the "big" divisor with (fluxed stacks of) space-time filling D7-branes also wrapping the "big" divisor (corresponding to a local minimum), we provide an explicit identification of the electron and the u-quark, as well as their SU (2-singlet cousins, with fermionic superpartners of four Wilson line moduli; their superpartners turn out to be very heavy, the Higgsino-mass parameter turns out to be large, one obtains one light (with a mass of 125 GeV) and one heavy Higgs and the gluino is long lived (from a collider point of view) providing a possible realization of "μ-Split Supersymmetry". By explicitly calculating the lifetimes of decays of the co-NLSPs - the first generation squark/slepton and a neutralino - to the LSP - the gravitino - as well as gravitino decays, we verify that BBN constraints relevant to the former as well as the requirement of the latter to be (more than) the age of the universe, are satisfied. For the purpose of calculation of the gravitino relic density in terms of the neutralino/slepton relic density, we evaluate the latter by evaluating the neutralino/slepton (co-)annihilation cross sections and hence show that the former satisfies the requirement for a dark matter candidate.

European Pulsar Timing Array limits on an isotropic stochastic gravitational-wave background

NASA Astrophysics Data System (ADS)

Lentati, L.; Taylor, S. R.; Mingarelli, C. M. F.; Sesana, A.; Sanidas, S. A.; Vecchio, A.; Caballero, R. N.; Lee, K. J.; van Haasteren, R.; Babak, S.; Bassa, C. G.; Brem, P.; Burgay, M.; Champion, D. J.; Cognard, I.; Desvignes, G.; Gair, J. R.; Guillemot, L.; Hessels, J. W. T.; Janssen, G. H.; Karuppusamy, R.; Kramer, M.; Lassus, A.; Lazarus, P.; Liu, K.; Osłowski, S.; Perrodin, D.; Petiteau, A.; Possenti, A.; Purver, M. B.; Rosado, P. A.; Smits, R.; Stappers, B.; Theureau, G.; Tiburzi, C.; Verbiest, J. P. W.

2015-11-01

We present new limits on an isotropic stochastic gravitational-wave background (GWB) using a six pulsar data set spanning 18 yr of observations from the 2015 European Pulsar Timing Array data release. Performing a Bayesian analysis, we fit simultaneously for the intrinsic noise parameters for each pulsar, along with common correlated signals including clock, and Solar system ephemeris errors, obtaining a robust 95 per cent upper limit on the dimensionless strain amplitude A of the background of A < 3.0 × 10-15 at a reference frequency of 1 yr-1 and a spectral index of 13/3, corresponding to a background from inspiralling supermassive black hole binaries, constraining the GW energy density to Ωgw(f)h2 < 1.1 × 10-9 at 2.8 nHz. We also present limits on the correlated power spectrum at a series of discrete frequencies, and show that our sensitivity to a fiducial isotropic GWB is highest at a frequency of ˜5 × 10-9 Hz. Finally, we discuss the implications of our analysis for the astrophysics of supermassive black hole binaries, and present 95 per cent upper limits on the string tension, Gμ/c2, characterizing a background produced by a cosmic string network for a set of possible scenarios, and for a stochastic relic GWB. For a Nambu-Goto field theory cosmic string network, we set a limit Gμ/c2 < 1.3 × 10-7, identical to that set by the Planck Collaboration, when combining Planck and high-ℓ cosmic microwave background data from other experiments. For a stochastic relic background, we set a limit of Ω ^relic_gw(f)h^2<1.2 × 10^{-9}, a factor of 9 improvement over the most stringent limits previously set by a pulsar timing array.

Mystery solved: discovery of extended radio emission in the merging galaxy cluster Abell 2146

NASA Astrophysics Data System (ADS)

Hlavacek-Larrondo, J.; Gendron-Marsolais, M.-L.; Fecteau-Beaucage, D.; van Weeren, R. J.; Russell, H. R.; Edge, A.; Olamaie, M.; Rumsey, C.; King, L.; Fabian, A. C.; McNamara, B.; Hogan, M.; Mezcua, M.; Taylor, G.

2018-04-01

Abell 2146 (z = 0.232) is a massive galaxy cluster currently undergoing a spectacular merger in the plane of the sky with a bullet-like morphology. It was the first system in which both the bow and upstream shock fronts were detected at X-ray wavelengths (Mach ˜2), yet deep Giant MetreWave Telescope 325 MHz observations failed to detect extended radio emission associated with the cluster as is typically seen in such systems. We present new, multiconfiguration 1-2 GHz Karl G. Jansky Very Large Array (VLA) observations of Abell 2146 totalling 16 h of observations. These data reveal for the first time the presence of an extended (≈850 kpc), faint radio structure associated with Abell 2146. The structure appears to harbour multiple components, one associated with the upstream shock that we classify as a radio relic and one associated with the subcluster core that is consisted as being a radio halo bounded by the bow shock. The newly detected structures have some of the lowest radio powers detected thus far in any cluster (P1.4 GHz, halo = 2.4 ± 0.2 × 1023 W Hz-1 and P1.4 GHz, relic = 2.2 ± 0.2 × 1023 W Hz-1). The flux measurement of the halo, as well as its morphology, also suggests that the halo was recently created (≈0.3 Gyr after core passage), consistent with the dynamical state of the cluster. These observations demonstrate the capacity of the upgraded VLA to detect extremely faint and extended radio structures. Based on these observations, we predict that many more radio relics and radio haloes in merging clusters should be detected by future radio facilities such as the Square Kilometre Array.

MC 2: A Deeper Look at ZwCl 2341.1+0000 with Bayesian Galaxy Clustering and Weak Lensing Analyses

DOE Office of Scientific and Technical Information (OSTI.GOV)

Benson, B.; Wittman, D. M.; Golovich, N.

ZwCl 2341.1+0000, a merging galaxy cluster with disturbed X-ray morphology and widely separated (~3 Mpc) double radio relics, was thought to be an extremely massive (10 - 30 X 10 14M⊙) and complex system with little known about its merger history. We present JVLA 2-4 GHz observations of the cluster, along with new spectroscopy from our Keck/DEIMOS survey, and apply Gaussian Mixture Modeling to the three-dimensional distribution of 227 con rmed cluster galaxies. After adopting the Bayesian Information Criterion to avoid over tting, which we discover can bias total dynamical mass estimates high, we nd that a three-substructure model withmore » a total dynamical mass estimate of 9:39 ± 0:81 X 10 14M⊙ is favored. We also present deep Subaru imaging and perform the rst weak lensing analysis on this system, obtaining a weak lensing mass estimate of 5:57±2:47X10 14M⊙. This is a more robust estimate because it does not depend on the dynamical state of the system, which is disturbed due to the merger. Our results indicate that ZwCl 2341.1+0000 is a multiple merger system comprised of at least three substructures, with the main merger that produced the radio relics occurring near to the plane of the sky, and a younger merger in the North occurring closer to the line of sight. Dynamical modeling of the main merger reproduces observed quantities (relic positions and polarizations, subcluster separation and radial velocity difference), if the merger axis angle of ~10 +34 -6 degrees and the collision speed at pericenter is ~1900 +300 -200 km/s.« less

MC 2: A Deeper Look at ZwCl 2341.1+0000 with Bayesian Galaxy Clustering and Weak Lensing Analyses

DOE PAGES

Benson, B.; Wittman, D. M.; Golovich, N.; ...

2017-05-16

ZwCl 2341.1+0000, a merging galaxy cluster with disturbed X-ray morphology and widely separated (~3 Mpc) double radio relics, was thought to be an extremely massive (10 - 30 X 10 14M⊙) and complex system with little known about its merger history. We present JVLA 2-4 GHz observations of the cluster, along with new spectroscopy from our Keck/DEIMOS survey, and apply Gaussian Mixture Modeling to the three-dimensional distribution of 227 con rmed cluster galaxies. After adopting the Bayesian Information Criterion to avoid over tting, which we discover can bias total dynamical mass estimates high, we nd that a three-substructure model withmore » a total dynamical mass estimate of 9:39 ± 0:81 X 10 14M⊙ is favored. We also present deep Subaru imaging and perform the rst weak lensing analysis on this system, obtaining a weak lensing mass estimate of 5:57±2:47X10 14M⊙. This is a more robust estimate because it does not depend on the dynamical state of the system, which is disturbed due to the merger. Our results indicate that ZwCl 2341.1+0000 is a multiple merger system comprised of at least three substructures, with the main merger that produced the radio relics occurring near to the plane of the sky, and a younger merger in the North occurring closer to the line of sight. Dynamical modeling of the main merger reproduces observed quantities (relic positions and polarizations, subcluster separation and radial velocity difference), if the merger axis angle of ~10 +34 -6 degrees and the collision speed at pericenter is ~1900 +300 -200 km/s.« less

The One to Multiple Automatic High Accuracy Registration of Terrestrial LIDAR and Optical Images

NASA Astrophysics Data System (ADS)

Wang, Y.; Hu, C.; Xia, G.; Xue, H.

2018-04-01

The registration of ground laser point cloud and close-range image is the key content of high-precision 3D reconstruction of cultural relic object. In view of the requirement of high texture resolution in the field of cultural relic at present, The registration of point cloud and image data in object reconstruction will result in the problem of point cloud to multiple images. In the current commercial software, the two pairs of registration of the two kinds of data are realized by manually dividing point cloud data, manual matching point cloud and image data, manually selecting a two - dimensional point of the same name of the image and the point cloud, and the process not only greatly reduces the working efficiency, but also affects the precision of the registration of the two, and causes the problem of the color point cloud texture joint. In order to solve the above problems, this paper takes the whole object image as the intermediate data, and uses the matching technology to realize the automatic one-to-one correspondence between the point cloud and multiple images. The matching of point cloud center projection reflection intensity image and optical image is applied to realize the automatic matching of the same name feature points, and the Rodrigo matrix spatial similarity transformation model and weight selection iteration are used to realize the automatic registration of the two kinds of data with high accuracy. This method is expected to serve for the high precision and high efficiency automatic 3D reconstruction of cultural relic objects, which has certain scientific research value and practical significance.

Palouse prairie - synaptic relics from a senior pseudo-botanist

USDA-ARS?s Scientific Manuscript database

Historically, vegetation of the Missoula Valley prairie has been regarded as "Agropyron-Festuca community," otherwise described as "Palouse bunchgrass prairie" or just "Palouse prairie." Synecology of this association has been well described starting in the 1920s, however there is no description of...

Supersymmetric model for dark matter and baryogenesis motivated by the recent CDMS result.

PubMed

Allahverdi, Rouzbeh; Dutta, Bhaskar; Mohapatra, Rabindra N; Sinha, Kuver

2013-08-02

We discuss a supersymmetric model for cogenesis of dark and baryonic matter where the dark matter (DM) has mass in the 8-10 GeV range as indicated by several direct detection searches, including most recently the CDMS experiment with the desired cross section. The DM candidate is a real scalar field. Two key distinguishing features of the model are the following: (i) in contrast with the conventional weakly interacting massive particle dark matter scenarios where thermal freeze-out is responsible for the observed relic density, our model uses nonthermal production of dark matter after reheating of the Universe caused by moduli decay at temperatures below the QCD phase transition, a feature which alleviates the relic overabundance problem caused by small annihilation cross section of light DM particles and (ii) baryogenesis occurs also at similar low temperatures from the decay of TeV scale mediator particles arising from moduli decay. A possible test of this model is the existence of colored particles with TeV masses accessible at the LHC.

Equilibrium thermodynamics and neutrino decoupling in quasi-metric cosmology

NASA Astrophysics Data System (ADS)

Østvang, Dag

2018-05-01

The laws of thermodynamics in the expanding universe are formulated within the quasi-metric framework. The quasi-metric cosmic expansion does not directly influence momenta of material particles, so the expansion directly cools null particles only (e.g., photons). Therefore, said laws differ substantially from their counterparts in standard cosmology. Consequently, all non-null neutrino mass eigenstates are predicted to have the same energy today as they had just after neutrino decoupling in the early universe. This indicates that the predicted relic neutrino background is strongly inconsistent with detection rates measured in solar neutrino detectors (Borexino in particular). Thus quasi-metric cosmology is in violent conflict with experiment unless some exotic property of neutrinos makes the relic neutrino background essentially undetectable (e.g., if all massive mass eigenstates decay into "invisible" particles over cosmic time scales). But in absence of hard evidence in favour of the necessary exotic neutrino physics needed to resolve said conflict, the current status of quasi-metric relativity has been changed to non-viable.

Playing God: Testing, Modeling, and Imitating Blood Miracles in Eighteenth-Century Europe.

PubMed

De Ceglia, Francesco Paolo

2017-01-01

In the late Middle Ages, rumors began to spread throughout Europe regarding blood miracles associated with the relics of martyrs. Centuries-old blood, pulverized or solidified and black in color, was said to return to its original bright red color, or else to liquefy or bubble under certain circumstances or on certain dates in the liturgical calendar. With the Reformation, in Protestant countries most of these relics were either destroyed or forgotten. In Catholic countries, on the contrary, blood miracles multiplied, reaching a peak between the seventeenth and eighteenth centuries. This article reconstructs the debate that sprang up in eighteenth-century Europe over the blood of Saint Januarius and the attempts made to disprove its miraculous properties, often not in written works, but by staging highly theatrical demonstrations. It examines the way in which, with phenomena as complex as miracles, the activities of testing alleged facts, creating elucidative models, and staging imitations intertwined over the centuries, often overlapping and becoming confused.

Phenomenology of ELDER dark matter

NASA Astrophysics Data System (ADS)

Kuflik, Eric; Perelstein, Maxim; Lorier, Nicolas Rey-Le; Tsai, Yu-Dai

2017-08-01

We explore the phenomenology of Elastically Decoupling Relic (ELDER) dark matter. ELDER is a thermal relic whose present density is determined primarily by the cross-section of its elastic scattering off Standard Model (SM) particles. Assuming that this scattering is mediated by a kinetically mixed dark photon, we argue that the ELDER scenario makes robust predictions for electron-recoil direct-detection experiments, as well as for dark photon searches. These predictions are independent of the details of interactions within the dark sector. Together with the closely related Strongly-Interacting Massive Particle (SIMP) scenario, the ELDER predictions provide a physically motivated, well-defined target region, which will be almost entirely accessible to the next generation of searches for sub-GeV dark matter and dark photons. We provide useful analytic approximations for various quantities of interest in the ELDER scenario, and discuss two simple renormalizable toy models which incorporate the required strong number-changing interactions among the ELDERs, as well as explicitly implement the coupling to electrons via the dark photon portal.

NASA's Hubble Spots a Relic from a Shredded Galaxy

NASA Image and Video Library

2017-12-08

February 17, 2012: Astronomers using NASA's Hubble Space Telescope may have found evidence for a cluster of young, blue stars encircling HLX-1, one of the first intermediate-mass black holes ever discovered. Astronomers believe the black hole may once have been at the core of a now-disintegrated dwarf galaxy. The discovery of the black hole and the possible star cluster has important implications for understanding the evolution of supermassive black holes and galaxies To read more go to: www.nasa.gov/mission_pages/hubble/science/shredded-relic.... Credit: NASA, ESA, and S. Farrell (Sydney Institute for Astronomy, University of Sydney) NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

Sound speed and viscosity of semi-relativistic relic neutrinos

DOE Office of Scientific and Technical Information (OSTI.GOV)

Krauss, Lawrence; Long, Andrew J., E-mail: krauss@asu.edu, E-mail: andrewjlong@kicp.uchicago.edu

2016-07-01

Generalized fluid equations, using sound speed c {sub eff}{sup 2} and viscosity c {sub vis}{sup 2} as effective parameters, provide a convenient phenomenological formalism for testing the relic neutrino 'null hypothesis,' i.e. that that neutrinos are relativistic and free-streaming prior to recombination. In this work, we relax the relativistic assumption and ask 'to what extent can the generalized fluid equations accommodate finite neutrino mass?' We consider both the mass of active neutrinos, which are largely still relativistic at recombination m {sup 2} / T {sup 2} ∼ 0.2, and the effect of a semi-relativistic sterile component. While there is nomore » one-to-one mapping between mass/mixing parameters and c {sub eff}{sup 2} and c {sub vis}{sup 2}, we demonstrate that the existence of a neutrino mass could induce a bias to measurements of c {sub eff}{sup 2} and c {sub vis}{sup 2} at the level of 0.01 m {sup 2} / T {sup 2} ∼ 10{sup -3}.« less

Constraints upon the spectral indices of relic gravitational waves by LIGO S5

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Y.; Tong, M. L.; Fu, Z. W.

With LIGO having achieved its design sensitivity and the LIGO S5 strain data being available, constraints on the relic gravitational waves (RGWs) become realistic. The analytical spectrum of RGWs generated during inflation depends sensitively on the initial condition, which is generically described by the index {beta}, the running index {alpha}{sub t}, and the tensor-to-scalar ratio r. By the LIGO S5 data of the cross-correlated two detectors, we obtain constraints on the parameters ({beta},{alpha}{sub t},r). As a main result, we have computed the theoretical signal-to-noise ratio of RGWs for various values of ({beta},{alpha}{sub t},r), using the cross-correlation for the given pairmore » of LIGO detectors. The constraints by the indirect bound on the energy density of RGWs by big bang nucleosynthesis and cosmic microwave background have been obtained, which turn out to be still more stringent than LIGO S5.« less

Direct constraints on minimal supersymmetry from Fermi-LAT observations of the dwarf galaxy Segue 1

DOE PAGES

Scott, Pat; Conrad, Jan; Edsjö, Joakim; ...

2010-01-26

The dwarf galaxy Segue 1 is one of the most promising targets for the indirect detection of dark matter. We examine what constraints 9 months of Fermi-LAT gamma-ray observations of Segue 1 place upon the Constrained Minimal Supersymmetric Standard Model (CMSSM), with the lightest neutralino as the dark matter particle. We also use nested sampling to explore the CMSSM parameter space, simultaneously fitting other relevant constraints from accelerator bounds, the relic density, electroweak precision observables, the anomalous magnetic moment of the muon and B-physics. We include spectral and spatial fits to the Fermi observations, a full treatment of the instrumentalmore » response and its related uncertainty, and detailed background models. We also perform an extrapolation to 5 years of observations, assuming no signal is observed from Segue 1 in that time. Our results marginally disfavour models with low neutralino masses and high annihilation cross-sections. Virtually all of these models are however already disfavoured by existing experimental or relic density constraints.« less

Progress report for a research program in theoretical high energy physics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Feldman, D.; Fried, H.M.; Jevicki, A.

This year's research has dealt with: superstrings in the early universe; the invisible axion emissions from SN1987A; quartic interaction in Witten's superstring field theory; W-boson associated multiplicity and the dual parton model; cosmic strings and galaxy formation; cosmic strings and baryogenesis; quark flavor mixing; p -- /bar p/ scattering at TeV energies; random surfaces; ordered exponentials and differential equations; initial value and back-reaction problems in quantum field theory; string field theory and Weyl invariance; the renormalization group and string field theory; the evolution of scalar fields in an inflationary universe, with and without the effects of gravitational perturbations; cosmic stringmore » catalysis of skyrmion decay; inflation and cosmic strings from dynamical symmetry breaking; the physic of flavor mixing; string-inspired cosmology; strings at high-energy densities and complex temperatures; the problem of non-locality in string theory; string statistical mechanics; large-scale structures with cosmic strings and neutrinos; the delta expansion for stochastic quantization; high-energy neutrino flux from ordinary cosmic strings; a physical picture of loop bremsstrahlung; cylindrically-symmetric solutions of four-dimensional sigma models; large-scale structure with hot dark matter and cosmic strings; the unitarization of the odderon; string thermodynamics and conservation laws; the dependence of inflationary-universe models on initial conditions; the delta expansion and local gauge invariance; particle physics and galaxy formation; chaotic inflation with metric and matter perturbations; grand-unified theories, galaxy formation, and large-scale structure; neutrino clustering in cosmic-string-induced wakes; and infrared approximations to nonlinear differential equations. 17 refs.« less

Observing a light dark matter beam with neutrino experiments

NASA Astrophysics Data System (ADS)

Deniverville, Patrick; Pospelov, Maxim; Ritz, Adam

2011-10-01

We consider the sensitivity of fixed-target neutrino experiments at the luminosity frontier to light stable states, such as those present in models of MeV-scale dark matter. To ensure the correct thermal relic abundance, such states must annihilate via light mediators, which in turn provide an access portal for direct production in colliders or fixed targets. Indeed, this framework endows the neutrino beams produced at fixed-target facilities with a companion “dark matter beam,” which may be detected via an excess of elastic scattering events off electrons or nuclei in the (near-)detector. We study the high-luminosity proton fixed-target experiments at LSND and MiniBooNE, and determine that the ensuing sensitivity to light dark matter generally surpasses that of other direct probes. For scenarios with a kinetically-mixed U(1)' vector mediator of mass mV, we find that a large volume of parameter space is excluded for mDM˜1-5MeV, covering vector masses 2mDM≲mV≲mη and a range of kinetic mixing parameters reaching as low as κ˜10-5. The corresponding MeV-scale dark matter scenarios motivated by an explanation of the galactic 511 keV line are thus strongly constrained.

Detecting boosted dark matter from the Sun with large volume neutrino detectors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Berger, Joshua; Cui, Yanou; Zhao, Yue, E-mail: jberger@slac.stanford.edu, E-mail: ycui@perimeterinstitute.ca, E-mail: zhaoyue@stanford.edu

2015-02-01

We study novel scenarios where thermal dark matter (DM) can be efficiently captured in the Sun and annihilate into boosted dark matter. In models with semi-annihilating DM, where DM has a non-minimal stabilization symmetry, or in models with a multi-component DM sector, annihilations of DM can give rise to stable dark sector particles with moderate Lorentz boosts. We investigate both of these possibilities, presenting concrete models as proofs of concept. Both scenarios can yield viable thermal relic DM with masses O(1)-O(100) GeV. Taking advantage of the energetic proton recoils that arise when the boosted DM scatters off matter, we proposemore » a detection strategy which uses large volume terrestrial detectors, such as those designed to detect neutrinos or proton decays. In particular, we propose a search for proton tracks pointing towards the Sun. We focus on signals at Cherenkov-radiation-based detectors such as Super-Kamiokande (SK) and its upgrade Hyper-Kamiokande (HK). We find that with spin-dependent scattering as the dominant DM-nucleus interaction at low energies, boosted DM can leave detectable signals at SK or HK, with sensitivity comparable to DM direct detection experiments while being consistent with current constraints. Our study provides a new search path for DM sectors with non-minimal structure.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Berger, Joshua; /SLAC; Cui, Yanou

We study novel scenarios where thermal dark matter (DM) can be efficiently captured in the Sun and annihilate into boosted dark matter. In models with semi-annihilating DM, where DM has a non-minimal stabilization symmetry, or in models with a multi-component DM sector, annihilations of DM can give rise to stable dark sector particles with moderate Lorentz boosts. We investigate both of these possibilities, presenting concrete models as proofs of concept. Both scenarios can yield viable thermal relic DM with masses O(1)-O(100) GeV. Taking advantage of the energetic proton recoils that arise when the boosted DM scatters off matter, we proposemore » a detection strategy which uses large volume terrestrial detectors, such as those designed to detect neutrinos or proton decays. In particular, we propose a search for proton tracks pointing towards the Sun. We focus on signals at Cherenkov-radiation-based detectors such as Super-Kamiokande (SK) and its upgrade Hyper-Kamiokande (HK). We find that with spin-dependent scattering as the dominant DM-nucleus interaction at low energies, boosted DM can leave detectable signals at SK or HK, with sensitivity comparable to DM direct detection experiments while being consistent with current constraints. Our study provides a new search path for DM sectors with non-minimal structure.« less

Unified scenario for composite right-handed neutrinos and dark matter

NASA Astrophysics Data System (ADS)

Davoudiasl, Hooman; Giardino, Pier Paolo; Neil, Ethan T.; Rinaldi, Enrico

2017-12-01

We entertain the possibility that neutrino masses and dark matter (DM) originate from a common composite dark sector. A minimal effective theory can be constructed based on a dark S U (3 )D interaction with three flavors of massless dark quarks; electroweak symmetry breaking gives masses to the dark quarks. By assigning a Z2 charge to one flavor, a stable "dark kaon" can provide a good thermal relic DM candidate. We find that "dark neutrons" may be identified as right handed Dirac neutrinos. Some level of "neutron-anti-neutron" oscillation in the dark sector can then result in non-zero Majorana masses for light standard model neutrinos. A simple ultraviolet completion is presented, involving additional heavy S U (3 )D-charged particles with electroweak and lepton Yukawa couplings. At our benchmark point, there are "dark pions" that are much lighter than the Higgs and we expect spectacular collider signals arising from the UV framework. This includes the decay of the Higgs boson to τ τ ℓℓ', where ℓ(ℓ') can be any lepton, with displaced vertices. We discuss the observational signatures of this UV framework in dark matter searches and primordial gravitational wave experiments; the latter signature is potentially correlated with the H →τ τ ℓℓ' decay.

Detecting boosted dark matter from the Sun with large volume neutrino detectors

NASA Astrophysics Data System (ADS)

Berger, Joshua; Cui, Yanou; Zhao, Yue

2015-02-01

We study novel scenarios where thermal dark matter (DM) can be efficiently captured in the Sun and annihilate into boosted dark matter. In models with semi-annihilating DM, where DM has a non-minimal stabilization symmetry, or in models with a multi-component DM sector, annihilations of DM can give rise to stable dark sector particles with moderate Lorentz boosts. We investigate both of these possibilities, presenting concrete models as proofs of concept. Both scenarios can yield viable thermal relic DM with masses O(1)-O(100) GeV. Taking advantage of the energetic proton recoils that arise when the boosted DM scatters off matter, we propose a detection strategy which uses large volume terrestrial detectors, such as those designed to detect neutrinos or proton decays. In particular, we propose a search for proton tracks pointing towards the Sun. We focus on signals at Cherenkov-radiation-based detectors such as Super-Kamiokande (SK) and its upgrade Hyper-Kamiokande (HK). We find that with spin-dependent scattering as the dominant DM-nucleus interaction at low energies, boosted DM can leave detectable signals at SK or HK, with sensitivity comparable to DM direct detection experiments while being consistent with current constraints. Our study provides a new search path for DM sectors with non-minimal structure.

[Towards an unified theory of the universe basic forces ("the everything theory")].

PubMed

Aguilar Peris, José

2004-01-01

Numerous efforts have been made in order to unify all the basic forces in nature. In 1967 the fusion of electromagnetic and weak forces was obtained and in 1973 a theoretical bridge between the electroweak and the strong forces have been constructed. This theory is waiting for experimental proofs in the CERN large hadron collider. The last stage would be "the everything theory", which includes the gravitational force. Only the so called superstring theory is a good candidate to overcome the incompatibility of the quantum mechanics and the general relativity, but this theory is not already achieved.

D=10 Chiral Tensionless Super p-BRANES

NASA Astrophysics Data System (ADS)

Bozhilov, P.

We consider a model for tensionless (null) super-p-branes with N chiral supersymmetries in ten-dimensional flat space-time. After establishing the symmetries of the action, we give the general solution of the classical equations of motion in a particular gauge. In the case of a null superstring (p=1) we find the general solution in an arbitrary gauge. Then, using a harmonic superspace approach, the initial algebra of first- and second-class constraints is converted into an algebra of Lorentz-covariant, BFV-irreducible, first-class constraints only. The corresponding BRST charge is as for a first rank dynamical system.

String inspired brane world cosmology.

PubMed

Germani, Cristiano; Sopuerta, Carlos F

2002-06-10

We consider brane world scenarios including the leading correction to the Einstein-Hilbert action suggested by superstring theory, the Gauss-Bonnet term. We obtain and study the complete set of equations governing the cosmological dynamics. We find they have the same form as those in Randall-Sundrum scenarios but with time-varying four-dimensional gravitational and cosmological constants. By studying the bulk geometry we show that this variation is produced by bulk curvature terms parametrized by the mass of a black hole. Finally, we show there is a coupling between these curvature terms and matter that can be relevant for early universe cosmology.

Thermal and optical performance of encapsulation systems for flat-plate photovoltaic modules

NASA Technical Reports Server (NTRS)

Minning, C. P.; Coakley, J. F.; Perrygo, C. M.; Garcia, A., III; Cuddihy, E. F.

1981-01-01

The electrical power output from a photovoltaic module is strongly influenced by the thermal and optical characteristics of the module encapsulation system. Described are the methodology and computer model for performing fast and accurate thermal and optical evaluations of different encapsulation systems. The computer model is used to evaluate cell temperature, solar energy transmittance through the encapsulation system, and electric power output for operation in a terrestrial environment. Extensive results are presented for both superstrate-module and substrate-module design schemes which include different types of silicon cell materials, pottants, and antireflection coatings.

Probing New Physics with Jets at the LHC

ScienceCinema

Harris, Robert

2017-12-09

The Large Hadron Collider at CERN has the potential to make a major discovery as early as 2008 from simple measurements of events with two high energy jets. This talk will present the jet trigger and analysis plans of the CMS collaboration, which were produced at the LHC Physics Center at Fermilab. Plans to search the two jet channel for generic signals of new particles and forces will be discussed. I will present the anticipated sensitivity of the CMS experiment to a variety of models of new physics, including quark compositeness, technicolor, superstrings, extra dimensions and grand unification.

No-Ghost Theorem for Neveu-Schwarz String in 0-Picture

NASA Astrophysics Data System (ADS)

Kohriki, M.; Kunitomo, H.; Murata, M.

2010-12-01

The no-ghost theorem for Neveu-Schwarz string is directly proved in 0-picture. The one-to-one correspondence between physical states in 0-picture and in the conventional (-1)-picture is confirmed. It is shown that a nontrivial metric consistent with the BRST cohomology is needed to define a positive semidefinite norm in the physical Hilbert space. As a by-product, we find a new inverse picture-changing operator, which is noncovariant but has a nonsingular operator product with itself. A possibility to construct a new gauge-invariant superstring field theory is discussed.

Device Engineering Towards Improved Tin Sulfide Solar Cell Performance and Performance Reproducibility

DOE Office of Scientific and Technical Information (OSTI.GOV)

Steinmann, Vera; Chakraborty, Rupak; Rekemeyer, Paul

2016-11-21

As novel absorber materials are developed and screened for their photovoltaic (PV) properties, the challenge remains to rapidly test promising candidates in high-performing PV devices. There is a need to engineer new compatible device architectures, including the development of novel transparent conductive oxides and buffer layers. Here, we consider the two approaches of a substrate-style and a superstrate-style device architecture for novel thin-film solar cells. We use tin sulfide as a test absorber material. Upon device engineering, we demonstrate new approaches to improve device performance and performance reproducibility.

Quasi-optical grids with thin rectangular patch/aperture elements

NASA Technical Reports Server (NTRS)

Wu, Te-Kao

1993-01-01

Theoretical analysis is presented for an efficient and accurate performance evaluation of quasi-optical grids comprised of thin rectangular patch/aperture elements with/without a dielectric substrate/superstrate. The convergence rate of this efficient technique is improved by an order of magnitude with the approximate edge conditions incorporated in the basis functions of the integral equation solution. Also presented are the interesting applications of this efficient analytical technique to the design and performance evaluation of the coupling grids and beam splitters in the optical systems as well as thermal protection sunshields used in the communication systems of satellites and spacecrafts.

Squeezed states in the theory of primordial gravitational waves

NASA Technical Reports Server (NTRS)

Grishchuk, Leonid P.

1992-01-01

It is shown that squeezed states of primordial gravitational waves are inevitably produced in the course of cosmological evolution. The theory of squeezed gravitons is very similar to the theory of squeezed light. Squeezed parameters and statistical properties of the expected relic gravity-wave radiation are described.

Competitive intelligence in the photonics industry: unlocking the box

NASA Astrophysics Data System (ADS)

James, Dick

2002-05-01

The photonics industry at present seems to be characterised by depressive chaos. Particularly in the telecommunications sector, what was perceived as a paradise of limitless growth has turned into a desert where shambling relics of formerly great companies stagger towards an unknown horizon, hoping for some signs of growth.

27 CFR 478.23 - Right of entry and examination.

Code of Federal Regulations, 2011 CFR

2011-04-01

..., FIREARMS, AND EXPLOSIVES, DEPARTMENT OF JUSTICE FIREARMS AND AMMUNITION COMMERCE IN FIREARMS AND AMMUNITION... ammunition kept or stored by any licensed manufacturer, licensed importer, or licensed dealer at such premises or any firearms curios or relics or ammunition kept or stored by any licensed collector at such...

27 CFR 478.23 - Right of entry and examination.

Code of Federal Regulations, 2010 CFR

2010-04-01

..., FIREARMS, AND EXPLOSIVES, DEPARTMENT OF JUSTICE FIREARMS AND AMMUNITION COMMERCE IN FIREARMS AND AMMUNITION... ammunition kept or stored by any licensed manufacturer, licensed importer, or licensed dealer at such premises or any firearms curios or relics or ammunition kept or stored by any licensed collector at such...

27 CFR 478.23 - Right of entry and examination.

Code of Federal Regulations, 2013 CFR

2013-04-01

..., FIREARMS, AND EXPLOSIVES, DEPARTMENT OF JUSTICE FIREARMS AND AMMUNITION COMMERCE IN FIREARMS AND AMMUNITION... ammunition kept or stored by any licensed manufacturer, licensed importer, or licensed dealer at such premises or any firearms curios or relics or ammunition kept or stored by any licensed collector at such...

27 CFR 478.23 - Right of entry and examination.

Code of Federal Regulations, 2014 CFR

2014-04-01

..., FIREARMS, AND EXPLOSIVES, DEPARTMENT OF JUSTICE FIREARMS AND AMMUNITION COMMERCE IN FIREARMS AND AMMUNITION... ammunition kept or stored by any licensed manufacturer, licensed importer, or licensed dealer at such premises or any firearms curios or relics or ammunition kept or stored by any licensed collector at such...

27 CFR 478.23 - Right of entry and examination.

Code of Federal Regulations, 2012 CFR

2012-04-01

..., FIREARMS, AND EXPLOSIVES, DEPARTMENT OF JUSTICE FIREARMS AND AMMUNITION COMMERCE IN FIREARMS AND AMMUNITION... ammunition kept or stored by any licensed manufacturer, licensed importer, or licensed dealer at such premises or any firearms curios or relics or ammunition kept or stored by any licensed collector at such...

The Electric Vocabulary

ERIC Educational Resources Information Center

Sheils, James

2012-01-01

Since the 1600s, the developments in the understanding of electrical phenomena have frequently altered the models and metaphors used by physicists to describe and explain their experiments. However, to this day, certain relics of past theories still drench the vocabulary of the subject, serving as distracting fog for future students. This article…

Approaching Pharmacometrics as a Paleontologist Would: Recovering the Links Between Drugs and the Body Through Reconstruction.

PubMed

Craig, M; González-Sales, M; Li, J; Nekka, F

2016-03-01

Our knowledge of dinosaurs comes primarily from the fossil record. Notwithstanding the condition of these vestiges, paleontologists reconstruct early reptilian life by comparison to previously discovered specimens. When relics are missing, reasonable deductions are used to fill in the gaps.

Apprenticeship Programs Expand with Help of Community Colleges

ERIC Educational Resources Information Center

Gonzalez, Jennifer

2011-01-01

The apprenticeship system, long considered an educational relic by some educators and policy makers, is gaining new attention as a model for improving job skills and meeting national college-completion goals. A number of states and community and technical colleges are working to strengthen and expand apprenticeship opportunities. They offer…

We Are All Mutants

ERIC Educational Resources Information Center

Timson, David J.

2017-01-01

Mutations can cause genetic diseases and the vast majority of these have no effective treatment. They raise some difficult questions on the boundaries of science and social science. Selective breeding to "improve" the human race (eugenics) is often regarded as a Victorian relic or Nazi fantasy. Yet, three fetuses with Down syndrome are…

Relict gas hydrates as possible reason of gas emission from shallow permafrost at the northern part of West Siberia

NASA Astrophysics Data System (ADS)

Chuvilin, Evgeny; Bukhanov, Boris; Tumskoy, Vladimir; Istomin, Vladimir; Tipenko, Gennady

2017-04-01

Intra-permafrost gas (mostly methane) is represent a serious geological hazards during exploration and development of oil and gas fields. Special danger is posed by large methane accumulations which usually confined to sandy and silty sand horizons and overlying in the frozen strata on the depth up to 200 meters. Such methane accumulations are widely spread in a number of gas fields in the northern part of Western Siberia. According to indirect indicators this accumulations can be relic gas hydrates, that formed earlier during favorable conditions for hydrate accumulation (1, 2). Until now, they could be preserved in the frozen sediments due to geological manifestation of the self-preservation effect of gas hydrates at temperatures below zero. These gas hydrate formations, which are lying above the gas hydrate stability zone today, are in a metastable state and are very sensitive to various anthropogenic impacts. During drilling and operation of production wells in the areas where the relic of gas hydrates can occur, there are active gas emission and gas explosion, that can lead to various technical complications up to the accident. Mathematical and experimental simulations were were conducted to evaluate the possibility of existence of relic gas hydrates in the northern part of West Siberia. The results of math simulations revealed stages of geological history when the gas hydrate stability zone began virtually from the ground surface and saturated in shallow permafrost horizons. Later permafrost is not completely thaw. Experimental simulations of porous gas hydrate dissociation in frozen soils and evaluation of self-preservation manifestation of gas hydrates at negative temperatures were carried out for identification conditions for relic gas hydrates existence in permafrost of northern part of West Siberia. Sandy and silty sand sediments were used in experimental investigations. These sediments are typical of most gas-seeping (above the gas hydrate stability zone) permafrost horizons. The results show that all investigated frozen hydrate-bearing sandy and silty sand samples in the temperature range from -16 °C to -2 °C are characterized by not complete decomposition of pore hydrate at relieving pressure below the equilibrium. It was observed that at typical north Western Siberian permafrost temperature of -6 ° C the safety of pore hydrate in frozen samples can reach 60% at the pressure reducing below the equilibrium. In was found that with increasing temperature and particle size (dispersity) the efficiency of pore hydrate self-preservation is decreased, but even at the temperature of -2 °C there is residual pore methane hydrate content in non-saline sandy samples. All this suggests about high preservation of methane hydrates in frozen sediments at non-equilibrium thermobaric conditions, close to reservoir conditions. Based on the results of mathematical and experimental simulations about the possibility of relic gas hydrates existence on permafrost depth up to 200 m in the northern part of Western Siberia on the less than 200 m due to geological manifestation of the self-preservation effect of gas hydrates. References. 1.Chuvilin EM, Yakushev VS, Perlova EV. Gas and gas hydrates in the permafrost of Bovanenkovo gas field, Yamal Peninsula, West Siberia. // Polarforschung 68: 215-219, 1998. (erschienen 2000). 2.Yakushev V.S., Chuvilin E.M. 2000. Natural gas and hydrate accumulation within permafrost in Russia. Cold Regions Science and Technology. 31: 189-197. These researches are supported by grant RSF №16-17-00051.

Controlling the physical parameters of crystalline CIGS nanowires for use in superstrate configuration using vapor phase epitaxy

NASA Astrophysics Data System (ADS)

Lee, Dongjin; Jeon, H. C.; Kang, T. W.; Kumar, Sunil

2018-03-01

Indium tin oxide (ITO) is a suitable candidate for smart windows and bifacial semi-transparent solar cell applications. In this study, highly crystalline CuInGaSe2 (CIGS) nanowires were successfully grown by horizontal-type vapor phase epitaxy on an ITO substrate. Length, diameter, and density of the nanowires were studied by varying the growth temperature (500, 520, and 560 °C), time (3.5, 6.5, and 9.5 h), and type of catalyst (In, Au, and Ga). Length, diameter, and density of the nanowires were found to be highly dependent on the growth conditions. At an optimized growth period and temperature of 3.5 h and 520 °C, respectively, the length and diameter of the nanowires were found to increase when grown in a catalyst-free environment. However, the density of the nanowires was found to be higher while using a catalyst during growth. Even in a catalyst-free environment, an Indium cluster formed at the bottom of the nanowires. The source of these nanowires is believed to be Indium from the ITO substrate which was observed in the EDS measurement. TEM-based EDS and line EDS indicated that the nanowires are made up of CIGS material with a very low Gallium content. XRD measurements also show the appearance of wurtzite CIS nanowires grown on ITO in addition to the chalcopyrite phase. PL spectroscopy was done to see the near-band-edge emission for finding band-to-band optical transition in this material. Optical response of the CIGS nanowire network was also studied to see the photovoltaic effect. This work creates opportunities for making real solar cell devices in superstrate configuration.

Hikers and other trail users

Treesearch

Robert C. Lucas

1971-01-01

Trail users seem neglected. Trail systems are limited, largely relics of fire control rather than designed for recreation; and total trail miles are probably declining. On the other hand, participation in various kinds of trail-oriented recreation is substantial and growing. Most activity is for short periods of time close to participants' homes. A varied and...

Sabotaging the California Dream

ERIC Educational Resources Information Center

Piland, William E.

2004-01-01

Higher education, the California dream for well over 2 million undergraduate students, is turning into a nightmare. The Golden State's promise of unparalleled access to community colleges and universities is fast becoming a tarnished relic of the past. And this state of affairs is occurring at a time when the demand for higher education has never…

Networking: A Key to Career Communication and Management Consulting Success

ERIC Educational Resources Information Center

Clark, Thomas

2009-01-01

Now that job security with one organization is a relic of the past and companies are outsourcing training and other "nonessential" functions, the author suggests in his career communication classes that students develop the same inventive strategies to plan their employment futures that management consultants use to market themselves in the 21st…

Historical Figure

ERIC Educational Resources Information Center

Shea, Rich

2005-01-01

As a teen in British boarding schools, Paul Watkins time traveled by writing stories set in the past. Now, the acclaimed novelist, toting duffel bags filled with wartime relics, encourages prep school kids to travel along. The author of eight novels and two memoirs, Watkins began his literary career at 23, with "Night Over Day Over Night," a novel…

Crumbs, Thieves, and Relics: Translation and Alien Humanism

ERIC Educational Resources Information Center

McAlhany, Joseph

2014-01-01

Terence's famous humanistic motto, "homo sum: humani nil a me alienum puto," was transmitted from antiquity to modernity as an isolated fragment of a surviving play, and was subjected to various forms of translation and interpretation. In this essay, Joseph McAlhany argues that fragments and translation, by their nature, resist…

Extremal noncommutative black holes as dark matter furnaces

NASA Astrophysics Data System (ADS)

Kawamoto, Shoichi; Wei, Chun-Yu; Wen, Wen-Yu

2017-09-01

In this paper, we consider dark matter annihilation in the gravitational field of noncommutative black holes. Instead of a violent fate predicted in the usual Hawking radiation, we propose a thermal equilibrium state where a mildly burning black hole relic is fueled by dark matter accretion at the final stage of evaporation.

[Diurnal variations in the alpha-particles flux as a possible evidence for changes in the movement velocity vector of an experimental set-up relative to a relic system].

PubMed

Liapidevskiĭ, V K

2001-01-01

The variations in the fine structure of distributions of the results of alpha-radioactivity measurements are explained by changes in the velocity of Earth's movement relative to some selected frame of reference.

Constructivist Pedagogies for Olympism Education

ERIC Educational Resources Information Center

Culpan, Ian; McBain, Sue

2012-01-01

Olympism as a philosophical concept has been highly contested and challenged for its relevancy in a contemporary world. Some scholars argue that Olympism is simply a relic of the modern age and has little educative and/or social legitimacy. Others argue that despite the criticism and its contested nature it remains one of the most coherent and…

The radiographic investigation of two Egyptian mummies.

PubMed

Fodor, J; Malott, J C; King, A Y

1983-01-01

Radiography is a well-recognized method of nondestructive analysis of art objects and ancient relics. The methods and techniques used in the examination of two ancient Egyptian mummies are presented here. Additionally, the use of radiographic findings to help substantiate alleged historical information and to establish sex, age, and pathology of each specimen is discussed.

Development and Evaluation of an RFID-Based Ubiquitous Learning Environment for Outdoor Learning

ERIC Educational Resources Information Center

Tan, Tan-Hsu; Liu, Tsung-Yu; Chang, Chi-Cheng

2007-01-01

Many issues have been identified in outdoor teaching, especially in places that lack the capacity to effectively present information about such subjects as historical relics, rare animals, and geological landscapes. This study proposes an Environment of Ubiquitous Learning with Educational Resources (EULER) based on radio frequency identification…

Fernbank Forest Birds in the Summer.

ERIC Educational Resources Information Center

Schmalz, Georgann

1991-01-01

Provided is a listing of the common nesting birds and the neotropical migrant birds with nesting records in the approximate 65 acres of Fernbank Forest which is a preserve of mature urban hardwoods and pines within 10 miles of downtown Atlanta and a relic of what was once a large, uninterrupted tract of the Piedmont forest. (JJK)

Colliders as a simultaneous probe of supersymmetric dark matter and Terascale cosmology

DOE Office of Scientific and Technical Information (OSTI.GOV)

Barenboim, Gabriela; /Valencia U.; Lykken, Joseph D.

2006-08-01

Terascale supersymmetry has the potential to provide a natural explanation of the dominant dark matter component of the standard {Lambda}CDM cosmology. However once we impose the constraints on minimal supersymmetry parameters from current particle physics data, a satisfactory dark matter abundance is no longer prima facie natural. This Neutralino Tuning Problem could be a hint of nonstandard cosmology during and/or after the Terascale era. To quantify this possibility, we introduce an alternative cosmological benchmark based upon a simple model of quintessential inflation. This benchmark has no free parameters, so for a given supersymmetry model it allows an unambiguous prediction ofmore » the dark matter relic density. As a example, we scan over the parameter space of the CMSSM, comparing the neutralino relic density predictions with the bounds from WMAP. We find that the WMAP-allowed regions of the CMSSM are an order of magnitude larger if we use the alternative cosmological benchmark, as opposed to {Lambda}CDM. Initial results from the CERN Large Hadron Collider will distinguish between the two allowed regions.« less

Reappraisal of dark matter co-annihilating with a top or bottom partner

NASA Astrophysics Data System (ADS)

Keung, Wai-Yee; Low, Ian; Zhang, Yue

2017-07-01

We revisit the calculation of the relic density of dark matter particles co-annihilating with a top or bottom partner by properly including the QCD bound-states (onia) effects of the colored partners as well as the relevant electroweak processes, which become important in the low-mass region. We carefully set up the complete framework that incorporates the relevant contributions and investigate their effects on the cosmologically preferred mass spectrum, which turn out to be comparable in size to those coming from the Sommerfeld enhancement. We apply the calculation to three scenarios: bino-stop and bino-sbottom co-annihilations in supersymmetry and a vector dark matter co-annihilating with a fermionic top partner. In addition, we confront our analysis of the relic abundance with recent direct detection experiments and collider searches at the LHC, which have important implications in the bino-stop and bino-sbottom scenarios. In particular, in the bino-stop case, recent LHC limits have excluded regions of parameter space with a direct detection rate that is above the neutrino floor.

A combined approach for the attribution of handwriting: the case of Antonio Stradivari's manuscripts

NASA Astrophysics Data System (ADS)

Fichera, Giusj Valentina; Dondi, Piercarlo; Licchelli, Maurizio; Lombardi, Luca; Ridolfi, Stefano; Malagodi, Marco

2016-11-01

Numerous artefacts from Antonio Stradivari's workshop are currently preserved in the "Museo del Violino" (Museum of the Violin) in Cremona, Italy. A large number of them are paper models containing instructions and technical notes by the great violin maker. After his death, this collection has had several owners, while new annotations added to the original ones, sometimes imitating Stradivari's handwriting, caused problems of authenticity. The attribution of these relics is a complex task and, until now, only a small part of them has been examined by palaeographers. This paper introduces a multi-analytical approach able to facilitate the study of handwriting in manuscripts with the combined use of image processing and X-ray fluorescence spectroscopy: the former provides a fast and automatic screening of documents; the latter allows to analyse the chemical composition of inks. For our tests, 17 paper relics, dated between 1684 and 1729, were chosen. Palaeographic analysis was used as reference. The results obtained showed the validity of the combined approach proposed herein: the two techniques proved to be complementary and useful to clarify the attribution of different pieces of handwriting.

RNA Relics and Origin of Life

PubMed Central

Demongeot, Jacques; Glade, Nicolas; Moreira, Andrés; Vial, Laurent

2009-01-01

A number of small RNA sequences, located in different non-coding sequences and highly preserved across the tree of life, have been suggested to be molecular fossils, of ancient (and possibly primordial) origin. On the other hand, recent years have revealed the existence of ubiquitous roles for small RNA sequences in modern organisms, in functions ranging from cell regulation to antiviral activity. We propose that a single thread can be followed from the beginning of life in RNA structures selected only for stability reasons through the RNA relics and up to the current coevolution of RNA sequences; such an understanding would shed light both on the history and on the present development of the RNA machinery and interactions. After presenting the evidence (by comparing their sequences) that points toward a common thread, we discuss a scenario of genome coevolution (with emphasis on viral infectious processes) and finally propose a plan for the reevaluation of the stereochemical theory of the genetic code; we claim that it may still be relevant, and not only for understanding the origin of life, but also for a comprehensive picture of regulation in present-day cells. PMID:20111682

Colliders as a simultaneous probe of supersymmetric dark matter and Terascale cosmology

NASA Astrophysics Data System (ADS)

Barenboim, Gabriela; Lykken, Joseph D.

2006-12-01

Terascale supersymmetry has the potential to provide a natural explanation of the dominant dark matter component of the standard ΛCDM cosmology. However once we impose the constraints on minimal supersymmetry parameters from current particle physics data, a satisfactory dark matter abundance is no longer prima facie natural. This Neutralino Tuning Problem could be a hint of nonstandard cosmology during and/or after the Terascale era. To quantify this possibility, we introduce an alternative cosmological benchmark based upon a simple model of quintessential inflation. This benchmark has no free parameters, so for a given supersymmetry model it allows an unambiguous prediction of the dark matter relic density. As a example, we scan over the parameter space of the CMSSM, comparing the neutralino relic density predictions with the bounds from WMAP. We find that the WMAP allowed regions of the CMSSM are an order of magnitude larger if we use the alternative cosmological benchmark, as opposed to ΛCDM. Initial results from the CERN Large Hadron Collider will distinguish between the two allowed regions.

Detectability and Uncertainties of the Supernova Relic Neutrino Background

NASA Astrophysics Data System (ADS)

Nakazato, Ken'ichiro; Mochida, Eri; Niino, Yuu; Suzuki, Hideyuki

The spectrum of the supernova relic neutrino (SRN) background from past stellar core collapses is calculated and its detectability at SK-Gd (Super-Kamiokande experiment with gadolinium-loaded water) is investigated. Several uncertainties on the flux of SRNs are considered. The core collapse rate at each redshift depends on the cosmic star formation rate, initial mass function and mass range of progenitors that end with a core collapse. The shock revival time is introduced as a parameter that should depend on the still unknown explosion mechanism of core collapse supernovae. Furthermore, since the neutrino luminosity of black-hole-forming failed supernovae is higher than that of ordinary supernovae, their contribution to SRNs is quantitatively estimated. Assuming the mass and metallicity ranges of their progenitors, the redshift dependence of the black hole formation rate is considered on the basis of the metallicity evolution of galaxies. As a result, it is found that the expected event rate of SRNs is comparable with other backgrounds at SK-Gd. Therefore, the required observation time to detect SRNs at SK-Gd depends strongly on the core collapse rate and it is 10-300 years.

Properties of Filamentary Sublimation Residues from Dispersions of Clay in Ice

NASA Technical Reports Server (NTRS)

Stephens, J. B.; Parker, T. J.; Saunders, R. S.; Laue, E. G.; Fanale, F. P.

1985-01-01

The properties of sublimate residues are of considerable interest in studies of the thermal modeling of Martian and cometary ice surfaces. The study of the formation of sand grains from this mantle on Martian polar ice is also supported by these experiments. To understand these properties, a series of low temperature vacuum experiments were run during which dirty ices that might be expected to be found in Martian polar caps and in comet nuclei were made and then freeze dried. In addition to using particulate material of appropriate grain size and minerology, particle nucleated ices were simulated by dispersing the particulates in the ice so that they did not contact one another. This noncontact dispersion was the most difficult requirement to achieve but the most rewarding in that it produced a new filamentary sublimate residue that was not a relic of the frozen dispersion. If the siliceous particles are allowed to touch one another in the ice the structure of the contacting particles in the ice will remain as a relic after the ice is sublimed away.

Axion cosmology

NASA Astrophysics Data System (ADS)

Marsh, David J. E.

2016-07-01

Axions comprise a broad class of particles that can play a major role in explaining the unknown aspects of cosmology. They are also well-motivated within high energy physics, appearing in theories related to CP-violation in the standard model, supersymmetric theories, and theories with extra-dimensions, including string theory, and so axion cosmology offers us a unique view onto these theories. I review the motivation and models for axions in particle physics and string theory. I then present a comprehensive and pedagogical view on the cosmology and astrophysics of axion-like particles, starting from inflation and progressing via BBN, the CMB, reionization and structure formation, up to the present-day Universe. Topics covered include: axion dark matter (DM); direct and indirect detection of axions, reviewing existing and future experiments; axions as dark radiation; axions and the cosmological constant problem; decays of heavy axions; axions and stellar astrophysics; black hole superradiance; axions and astrophysical magnetic fields; axion inflation, and axion DM as an indirect probe of inflation. A major focus is on the population of ultralight axions created via vacuum realignment, and its role as a DM candidate with distinctive phenomenology. Cosmological observations place robust constraints on the axion mass and relic density in this scenario, and I review where such constraints come from. I next cover aspects of galaxy formation with axion DM, and ways this can be used to further search for evidence of axions. An absolute lower bound on DM particle mass is established. It is ma > 10-24eV from linear observables, extending to ma ≳ 10-22eV from non-linear observables, and has the potential to reach ma ≳ 10-18eV in the future. These bounds are weaker if the axion is not all of the DM, giving rise to limits on the relic density at low mass. This leads to the exciting possibility that the effects of axion DM on structure formation could one day be detected, and the axion mass and relic density measured from cosmological observables.

Fusion of Geophysical Images in the Study of Archaeological Sites

NASA Astrophysics Data System (ADS)

Karamitrou, A. A.; Petrou, M.; Tsokas, G. N.

2011-12-01

This paper presents results from different fusion techniques between geophysical images from different modalities in order to combine them into one image with higher information content than the two original images independently. The resultant image will be useful for the detection and mapping of buried archaeological relics. The examined archaeological area is situated in Kampana site (NE Greece) near the ancient theater of Maronia city. Archaeological excavations revealed an ancient theater, an aristocratic house and the temple of the ancient Greek God Dionysus. Numerous ceramic objects found in the broader area indicated the probability of the existence of buried urban structure. In order to accurately locate and map the latter, geophysical measurements performed with the use of the magnetic method (vertical gradient of the magnetic field) and of the electrical method (apparent resistivity). We performed a semi-stochastic pixel based registration method between the geophysical images in order to fine register them by correcting their local spatial offsets produced by the use of hand held devices. After this procedure we applied to the registered images three different fusion approaches. Image fusion is a relatively new technique that not only allows integration of different information sources, but also takes advantage of the spatial and spectral resolution as well as the orientation characteristics of each image. We have used three different fusion techniques, fusion with mean values, with wavelets by enhancing selected frequency bands and curvelets giving emphasis at specific bands and angles (according the expecting orientation of the relics). In all three cases the fused images gave significantly better results than each of the original geophysical images separately. The comparison of the results of the three different approaches showed that the fusion with the use of curvelets, giving emphasis at the features' orientation, seems to give the best fused image. In the resultant image appear clear linear and ellipsoid features corresponding to potential archaeological relics.

Stau coannihilation, compressed spectrum, and SUSY discovery potential at the LHC

NASA Astrophysics Data System (ADS)

Aboubrahim, Amin; Nath, Pran; Spisak, Andrew B.

2017-06-01

The lack of observation of supersymmetry thus far implies that the weak supersymmetry scale is larger than what was thought before the LHC era. This observation is strengthened by the Higgs boson mass measurement at ˜125 GeV , which within supersymmetric models implies a large loop correction and a weak supersymmetry scale lying in the several TeV region. In addition if neutralino is the dark matter, its relic density puts further constraints on models often requiring coannihilation to reduce the neutralino relic density to be consistent with experimental observation. The coannihilation in turn implies that the mass gap between the lightest supersymmetric particle and the next to lightest supersymmetric particle will be small, leading to softer final states and making the observation of supersymmetry challenging. In this work we investigate stau coannihilation models within supergravity grand unified models and the potential of discovery of such models at the LHC in the post-Higgs boson discovery era. We utilize a variety of signal regions to optimize the discovery of supersymmetry in the stau coannihilation region. In the analysis presented we impose the relic density constraint as well as the constraint of the Higgs boson mass. The range of sparticle masses discoverable up to the optimal integrated luminosity of the HL-LHC is investigated. It is found that the mass difference between the stau and the neutralino does not exceed ˜20 GeV over the entire mass range of the models explored. Thus the discovery of a supersymmetric signal arising from the stau coannihilation region will also provide a measurement of the neutralino mass. The direct detection of neutralino dark matter is analyzed within the class of stau coannihilation models investigated. The analysis is extended to include multiparticle coannihilation where stau along with chargino and the second neutralino enter into the coannihilation process.

Mapping a disordered portion of the Brz2001-binding site on a plant monooxygenase, DWARF4, using a quartz-crystal microbalance biosensor-based T7 phage display.

PubMed

Takakusagi, Yoichi; Manita, Daisuke; Kusayanagi, Tomoe; Izaguirre-Carbonell, Jesus; Takakusagi, Kaori; Kuramochi, Kouji; Iwabata, Kazuki; Kanai, Yoshihiro; Sakaguchi, Kengo; Sugawara, Fumio

2013-04-01

In small-molecule/protein interaction studies, technical difficulties such as low solubility of small molecules or low abundance of protein samples often restrict the progress of research. Here, we describe a quartz-crystal microbalance (QCM) biosensor-based T7 phage display in combination use with a receptor-ligand contacts (RELIC) bioinformatics server for application in a plant Brz2001/DWARF4 system. Brz2001 is a brassinosteroid biosynthesis inhibitor in the less-soluble triazole series of compounds that targets DWARF4, a cytochrome P450 (Cyp450) monooxygenase containing heme and iron. Using a Brz2001 derivative that has higher solubility in 70% EtOH and forms a self-assembled monolayer on gold electrode, we selected 34 Brz2001-recognizing peptides from a 15-mer T7 phage-displayed random peptide library using a total of four sets of one-cycle biopanning. The RELIC/MOTIF program revealed continuous and discontinuous short motifs conserved within the 34 Brz2001-selected 15-mer peptide sequences, indicating the increase of information content for Brz2001 recognition. Furthermore, an analysis of similarity between the 34 peptides and the amino-acid sequence of DWARF4 using the RELIC/MATCH program generated a similarity plot and a cluster diagram of the amino-acid sequence. Both of these data highlighted an internally located disordered portion of a catalytic site on DWARF4, indicating that this portion is essential for Brz2001 recognition. A similar trend was also noted by an analysis using another 26 Brz2001-selected peptides, and not observed using the 27 gold electrode-recognizing control peptides, demonstrating the reproducibility and specificity of this method. Thus, this affinity-based strategy enables high-throughput detection of the small-molecule-recognizing portion on the target protein, which overcomes technical difficulties such as sample solubility or preparation that occur when conventional methods are used.

Study of curved glass photovoltaic module and module electrical isolation design requirements

NASA Technical Reports Server (NTRS)

1980-01-01

The design of a 1.2 by 2.4 m curved glass superstrate and support clip assembly is presented, along with the results of finite element computer analysis and a glass industry survey conducted to assess the technical and economic feasibility of the concept. Installed costs for four curved glass module array configurations are estimated and compared with cost previously reported for comparable flat glass module configurations. Electrical properties of candidate module encapsulation systems are evaluated along with present industry practice for the design and testing of electrical insulation systems. Electric design requirements for module encapsulation systems are also discussed.

Study of curved glass photovoltaic module and module electrical isolation design requirements

NASA Astrophysics Data System (ADS)

1980-06-01

The design of a 1.2 by 2.4 m curved glass superstrate and support clip assembly is presented, along with the results of finite element computer analysis and a glass industry survey conducted to assess the technical and economic feasibility of the concept. Installed costs for four curved glass module array configurations are estimated and compared with cost previously reported for comparable flat glass module configurations. Electrical properties of candidate module encapsulation systems are evaluated along with present industry practice for the design and testing of electrical insulation systems. Electric design requirements for module encapsulation systems are also discussed.

On the Modeling and Experimentation of Electromagnetically Coupled Microstrip Dipole Arrays in a Substrate-Superstrate

DTIC Science & Technology

1990-01-01

methodology for the modeling and design antenna arrays and microstrip discontinuities for microwave circuit applications. I believe that certain outstanding...of the EMCobtain the design curves w as reported later [5]-[7] based on t a s e s i o eh v e n r p r e e e ty [ ] 1 ) nt i solving a Pocklington type...by j"d I ’ My) dy. (8) Y V n In the two design equations ((6) and (7)), Yn,,f, m/ Vn and = Y,11+ Y (2) Y,, can be determined by the method of moments

Implementing odd-axions in dimensional oxidation of 4D non-geometric type IIB scalar potential

NASA Astrophysics Data System (ADS)

Shukla, Pramod

2016-01-01

In a setup of type IIB superstring compactification on an orientifold of a T6 /Z4 sixfold, the presence of geometric flux (ω) and non-geometric fluxes (Q, R) is implemented along with the standard NS-NS and RR three-form fluxes (H, F). After computing the F/D-term contributions to the N = 1 four dimensional effective scalar potential, we rearrange the same into 'suitable' pieces by using a set of new generalized flux orbits. Subsequently, we dimensionally oxidize the various pieces of the total four dimensional scalar potential to guess their ten-dimensional origin.

Towards Lagrangian formulations of mixed-symmetry higher spin fields on AdS-space within BFV-BRST formalism

NASA Astrophysics Data System (ADS)

Reshetnyak, A. A.

2010-11-01

The spectrum of superstring theory on the AdS 5 × S 5 Ramond-Ramond background in tensionless limit contains integer and half-integer higher-spin fields subject at most to two-rows Young tableaux Y( s 1, s 2). We review the details of a gauge-invariant Lagrangian description of such massive and massless higher-spin fields in anti-de-Sitter spaces with arbitrary dimensions. The procedure is based on the construction of Verma modules, its oscillator realizations and of a BFV-BRST operator for non-linear algebras encoding unitary irreducible representations of AdS group.

COBE satellite measurement, hyperspheres, superstrings and the dimension of spacetime.

NASA Astrophysics Data System (ADS)

El Naschie, M. S.

1998-08-01

The first part of the paper attempts to establish connections between hypersphere backing in infinite dimensions, the expectation value of dimE(∞) spacetime and the COBE measurement of the microwave background radiation. One of the main results reported here is that the mean sphere in S(∞) spans a four dimensional manifold and is thus equal to the expectation value of the topological dimension of E(∞). In the second part the author introduces within a general theory, a probabilistic justification for a compactification which reduces an infinite dimensional spacetime E(∞) (n = ∞) to a four dimensional one (DT = n = 4).

Integral glass encapsulation for solar arrays

NASA Technical Reports Server (NTRS)

Landis, G. A.

1981-01-01

Electrostatic bonding technology, an encapsulation technique for terrestrial solar array was developed. The process produces full integral, hermetic bonds with no adhesives or pottants. Panels of six solar cells on a simple glass superstrate were produced. Electrostatic bonding for making the cell front contact was also developed. A metal mesh is trapped into contact with the cell front during the bonding process. Six cell panels using the bonded mesh as the only cell front contact were produced. The possibility of using lower cost glass, with a higher thermal expansion mismatch to silicon, by making lower temperature bonds is developed. However, this requires a planar surface cell.

Performance of a compact, hybrid optical evanescent-wave sensor for chemical and biological applications

NASA Astrophysics Data System (ADS)

Helmers, H.; Greco, Pierre; Benech, Pierre; Rustad, Rolf; Kherrat, Rochdi; Bouvier, Gérard

1996-02-01

We describe a hybrid evanescent-wave sensor component that we fabricated by using an integrated optical interferometer with a specially adapted photodetector array. The design of the interferometer is based on the use of tapered waveguides to obtain two intersecting collimated beams. Phase shifts can be measured with an angular precision of better than 10-3 rad, which corresponds to a superstrate index change inferior of 10-6 with our structure. The interest in the device as a chemical sensor is experimentally demonstrated. The same optical component could be used in a variety of other sensor applications, e.g., biological and immunological sensors.

Encapsulation task of the low-cost silicon solar array project. Investigation of test methods, material properties, and processes for solar cell encapsulants

NASA Technical Reports Server (NTRS)

Willis, P. B.; Baum, B.; White, R. A.

1978-01-01

The results of an investigation of solar module encapsulation systems applicable to the Low-Cost Solar Array Project 1986 cost and performance goals are presented. Six basic construction elements were identified and their specific uses in module construction defined. A uniform coating basis was established for each element. The survey results were also useful in revealing price ranges for classes of materials and estimating the cost allocation for each element within the encapsulating cost goal. The six construction elements were considered to be substrates, superstrates, pottants, adhesives, outer covers and back covers.

Gödel universes in string theory

NASA Astrophysics Data System (ADS)

Barrow, John D.; Dabrowski, Mariusz P.

1998-11-01

We show that homogeneous Gödel spacetimes need not contain closed timelike curves in low-energy-effective string theories. We find exact solutions for the Gödel metric in string theory for the full O(α') action including both dilaton and axion fields. The results are valid for bosonic, heterotic and super-strings. To first order in the inverse string tension α', these solutions display a simple relation between the angular velocity of the Gödel universe, Ω, and the inverse string tension of the form α'=1/Ω2 in the absence of the axion field. The generalization of this relationship is also found when the axion field is present.

A microscopic description of black hole evaporation via holography

DOE PAGES

Berkowitz, Evan; Hanada, Masanori; Maltz, Jonathan

2016-07-19

Here, we propose a description of how a large, cold black hole (black zero-brane) in type IIA superstring theory evaporates into freely propagating D0-branes, by solving the dual gauge theory quantitatively. The energy spectrum of emitted D0-branes is parametrically close to thermal when the black hole is large. The black hole, while initially cold, gradually becomes an extremely hot and stringy object as it evaporates. As it emits D0-branes, its emission rate speeds up and it evaporates completely without leaving any remnant. Hence this system provides us with a concrete holographic description of black hole evaporation without information loss.

A microscopic description of black hole evaporation via holography

DOE Office of Scientific and Technical Information (OSTI.GOV)

Berkowitz, Evan; Hanada, Masanori; Maltz, Jonathan

Here, we propose a description of how a large, cold black hole (black zero-brane) in type IIA superstring theory evaporates into freely propagating D0-branes, by solving the dual gauge theory quantitatively. The energy spectrum of emitted D0-branes is parametrically close to thermal when the black hole is large. The black hole, while initially cold, gradually becomes an extremely hot and stringy object as it evaporates. As it emits D0-branes, its emission rate speeds up and it evaporates completely without leaving any remnant. Hence this system provides us with a concrete holographic description of black hole evaporation without information loss.

Investigation of test methods, material properties, and processes for solar cell encapsulants. Encapsulation task of the low-cost silicon solar array project

NASA Technical Reports Server (NTRS)

1977-01-01

During this quarter, flat-plate solar collector systems were considered and six basic construction elements were identified: outer coatings, superstrates, pottants, substrates, undercoats, and adhesives. Materials surveys were then initiated to discover either generic classes or/and specific products to function as each construction element. Cost data included in the surveys permit ready evaluation of each material. Silicones, fluorocarbons, glass, and acrylic polymers have the highest inherent weatherability of materials studied to date. Only acrylics, however, combine low costs, environmental resistance, and potential processability. This class will receive particular emphasis.

On the elliptic genera of manifolds of Spin(7) holonomy

DOE PAGES

Benjamin, Nathan; Harrison, Sarah M.; Kachru, Shamit; ...

2015-12-16

Superstring compactification on a manifold of Spin(7) holonomy gives rise to a 2d worldsheet conformal field theory with an extended supersymmetry algebra. The N=1 superconformal algebra is extended by additional generators of spins 2 and 5/2, and instead of just superconformal symmetry one has a c = 12 realization of the symmetry group SW(3/2,2). In this paper, we compute the characters of this supergroup and decompose the elliptic genus of a general Spin(7) compactification in terms of these characters. Here, we find suggestive relations to various sporadic groups, which are made more precise in a companion paper.

E sub 6 leptoquarks and the solar neutrino problem

NASA Technical Reports Server (NTRS)

Roulet, Esteban

1991-01-01

The possibility that non-conventional neutrino oscillations take place in the superstring inspired E sub 6 models is considered. In this context, the influence of leptoquark mediated interactions of the neutrinos with nucleons in the resonant flavor conversion is discussed. It is shown that this effect can be significant for v sub e - v sub tau oscillations if these neutrinos have masses required in the ordinary Mikheyev-Smirnov-Wolfenstein (MSW) effect, and may lead to a solution of the solar neutrino problem even in the absence of vacuum mixings. On the other hand, this model cannot lead to a resonant behavior in the sun if the neutrinos are massless.

Numerical investigation of refractometric sensor elements based on side polished fibres using the Galerkin method

NASA Astrophysics Data System (ADS)

Karakoleva, E. I.; Andreev, A. Tz; Zafirova, B. S.

2006-12-01

The Galerkin method was applied to solve the vector wave equation in order to determine the propagation constants and the transverse electric fields of the modes propagating along side polished single-mode and two-mode optical fibres. The effective refractive indices of the modes were calculated depending on the values of the residual cladding (minimum distance between a fibre core and a polished surface) and the superstrate refractive index. The influence of the fibre parameters and working wavelength on the refractometric sensitivity was estimated in the case when a side polished fibre with inscribed in-fibre Bragg grating is used as a sensor element.

Career Academies as Instruments of School Reform and Change

ERIC Educational Resources Information Center

Blomenkamp, Joel

2009-01-01

For many, today's classroom is a relic of an industrial-age school system that, perhaps, has outlived its usefulness. Educator Joel Blomenkamp suggests that the career academy model is one way to enter a new age of education and learning--one in which students are excited about the acquisition of knowledge because they are learning in a dynamic…

Eastern Hemlock Forests: Guidelines to Minimize the Impacts of Hemlock Woolly Adelgid

Treesearch

Jeffrey S. Ward; Michael E. Montgomery; Carole A.S.-J. Cheah; Brad P. Onken; Richard S. Cowles

2004-01-01

Eastern hemlock (Tsuga canadensis) is the most shade-tolerant and long-lived tree species in Eastern North America. Its unsurpassed ability to tolerate low light enables it to form dense canopies and stands that provide a unique habitat for many plant and wildlife species. Carolina hemlock (Tsuga caroliniana) is a relic species...

Searching the Soul: Veterans and Their Arts and Crafts

ERIC Educational Resources Information Center

Hasio, Cindy

2011-01-01

For military veterans suffering from the long-term trauma of warfare, arts and crafts become much more than the fabrication of relics; they can literally save the spirit. Dialogue and interaction between the veterans, volunteers, and staff are crucial to the success of veterans' arts and crafts program. The purpose of this research was threefold.…

Baryonic dark matter

NASA Technical Reports Server (NTRS)

Silk, Joseph

1991-01-01

Both canonical primordial nucleosynthesis constraints and large-scale structure measurements, as well as observations of the fundamental cosmological parameters, appear to be consistent with the hypothesis that the universe predominantly consists of baryonic dark matter (BDM). The arguments for BDM to consist of compact objects that are either stellar relics or substellar objects are reviewed. Several techniques for searching for halo BDM are described.

Local Rural Product as a "Relic" Spatial Strategy in Globalised Rural Spaces: Evidence from County Clare (Ireland)

ERIC Educational Resources Information Center

Wilson, Geoff A.; Whitehead, Ian

2012-01-01

Using a case study from County Clare (Ireland), this study critically analyses notions of "local" rural production. It investigates where rural businesses source the different components of their products and how these interrelate with the locality, how local businesses use the notion of "local" in their product branding, and…

Congress Considers Linking Student-Loan Terms to Income

ERIC Educational Resources Information Center

Smith, Lauren

2007-01-01

Faced with having to make a decision between the career they want and one that will pay enough for them to climb out of debt, many college students are choosing the latter. This trend has alarmed some observers and has revived interest in an idea once thought to be a relic of the Clinton administration: income-contingent repayment. Legislation…

Peer Mentoring as an Academic Resource: Or "My Friend Says..."

ERIC Educational Resources Information Center

Maher, JaneMaree; Lindsay, Jo; Peel, Vicki; Twomey, Christina

2006-01-01

On current projections in could take thirty years for women to be equally represented in the academic workplace. Traditional methods of mentoring by senior staff often seem relics of an earlier era, but here a group of more junior academics reflect on the success of a peer-mentoring exercise which helped transform their first experience of…

A Study on Kinmen Resident's Perception of Tourism Development and Culture Heritage Impact

ERIC Educational Resources Information Center

Wang, Yi-Ping

2016-01-01

Tourism development could drive the enhancement of national income and the demands for international tourism that tourism benefits have become the key source of national revenue. The integration of cultural relics with tourism development to drive the national or regional development has currently become the world trend. Making good use of the…

Guidelines on the use of molecular genetics in reintroduction programs

Treesearch

Michael K. Schwartz

2005-01-01

The use of molecular genetics can play a key role in reintroduction efforts. Prior to the introduction of any individuals, molecular genetics can be used to identify the most appropriate source population for the reintroduction, ensure that no relic populations exist in the reintroduction area, and guide captive breeding programs. The use of molecular genetics post-...

A Paradigm for Learning in a World of Continuous Change

ERIC Educational Resources Information Center

Thompson, Scott

2014-01-01

Through ongoing rapid-fire changes in the nature of communications, the social, professional, and political landscapes of our time are rapidly transforming. But the prevailing paradigm in most schools and school systems is a relic of the industrial revolution. Schools and school systems must adopt a new paradigm for learning if they are to remain…

Low-Frequency VLA Observations of Abell 754: Evidence for a Cluster Radio Halo and Possible Radio Relics

DTIC Science & Technology

2001-10-01

core passage of the dark matter subcluster, was not violent enough to produce a shock wave in the dense main cluster core. The core was only...such as Chandra. At later merger stages, turbulent gas motion, which is stirred by violently relaxing dark matter cores, should have erased many of

Golden Relics & Historical Standards: How the OECD is Expanding Global Education Governance through PISA for Development

ERIC Educational Resources Information Center

Addey, Camilla

2017-01-01

Setting this paper against the backdrop of scholarly research on recent changes in the OECD's approach and workings in education, I analyse how the OECD has reinforced its infrastructural and epistemological global governance through the Programme for International Student Assessment (PISA) for Development (PISA-D). Drawing on qualitative data,…

Claim audits: a relic of the indemnity age?

PubMed

Ellender, D E

1997-09-01

Traditional claim audits offering quick fixes to specific problems or to recover overpayments will not provide benefit managers with the data and action plan they need to make informed decisions about cost-effective benefit administration. Today's benefits environment calls for a comprehensive review of claim administration, incorporating traditional audit techniques into a quality improvement audit process.

Unified scenario for composite right-handed neutrinos and dark matter

DOE PAGES

Davoudiasl, Hooman; Giardino, Pier Paolo; Neil, Ethan T.; ...

2017-12-06

In this study, we entertain the possibility that neutrino masses and dark matter (DM) originate from a common composite dark sector. A minimal effective theory can be constructed based on a dark SU(3) D interaction with three flavors of massless dark quarks; electroweak symmetry breaking gives masses to the dark quarks. By assigning a Z 2 charge to one flavor, a stable “dark kaon” can provide a good thermal relic DM candidate. We find that “dark neutrons” may be identified as right handed Dirac neutrinos. Some level of “neutron-anti-neutron” oscillation in the dark sector can then result in non-zero Majoranamore » masses for light standard model neutrinos. A simple ultraviolet completion is presented, involving additional heavy SU(3) D-charged particles with electroweak and lepton Yukawa couplings. At our benchmark point, there are “dark pions” that are much lighter than the Higgs and we expect spectacular collider signals arising from the UV framework. This includes the decay of the Higgs boson to ττℓℓ', where ℓ(ℓ ') can be any lepton, with displaced vertices. Finally, we discuss the observational signatures of this UV framework in dark matter searches and primordial gravitational wave experiments; the latter signature is potentially correlated with the H → ττℓℓ' decay.« less

Light dark matter, naturalness, and the radiative origin of the electroweak scale

DOE PAGES

Altmannshofer, Wolfgang; Bardeen, William A.; Bauer, Martin; ...

2015-01-09

We study classically scale invariant models in which the Standard Model Higgs mass term is replaced in the Lagrangian by a Higgs portal coupling to a complex scalar field of a dark sector. We focus on models that are weakly coupled with the quartic scalar couplings nearly vanishing at the Planck scale. The dark sector contains fermions and scalars charged under dark SU(2) × U(1) gauge interactions. Radiative breaking of the dark gauge group triggers electroweak symmetry breaking through the Higgs portal coupling. Requiring both a Higgs boson mass of 125.5 GeV and stability of the Higgs potential up tomore » the Planck scale implies that the radiative breaking of the dark gauge group occurs at the TeV scale. We present a particular model which features a long-range abelian dark force. The dominant dark matter component is neutral dark fermions, with the correct thermal relic abundance, and in reach of future direct detection experiments. The model also has lighter stable dark fermions charged under the dark force, with observable effects on galactic-scale structure. Collider signatures include a dark sector scalar boson with mass ≲ 250 GeV that decays through mixing with the Higgs boson, and can be detected at the LHC. As a result, the Higgs boson, as well as the new scalar, may have significant invisible decays into dark sector particles.« less

Rock cities, periglacial mass-wasting, and honeycomb weathering in Warren County, northwestern Pennsylvania

DOE Office of Scientific and Technical Information (OSTI.GOV)

Inners, J.D.; Sevon, W.D.; Moore, M.E.

1993-03-01

Imposing hilltop rock-cities developed from widely jointed outcrops of Olean conglomerate (Lower Pennsylvanian) create picturesque scenery on the Allegheny High Plateau in Warren Co., Pa. At least six such rock cities 2 to 5 acres in extent are associated with the Late Wisconsinan glacial border in the northern half of the county. Farther to the south, jumbled Olean and Knapp (Lower Mississippian) joint blocks occur on steep slopes below valley-wall cliffs. The rock cities and accumulations of displaced joint blocks are largely relics of Late Wisconsinan periglacial mass-wasting. Frost splitting initiated opening of bedrock joints to form buildings. Gravity, soilmore » wedging, and possibly gelifluction then widened the fissures into streets. Gelifluction moved blocks downslope and oriented their long axes parallel with slope (Warren Rocks). Forward toppling of high, unstable blocks contributed to mass-movement on some steep slopes (Rimrock). Today, rock cities and downslope blocks are stable in areas of gentle (less than 10 percent) slopes, but toppling, solifluction, creep, and debris flows cause continued slow movement of large blocks on moderately steep to steep (greater than 30 percent) slopes. Blocks of Olean and Knapp conglomerate have both stratabound pitting and intricate honeycomb weathering. Deep pitting is controlled largely by variations in silica cementation. Honeycomb weathering is most evident in sandy layers and results from patterns of iron-oxide impregnation. Both are Holocene surface-weathering processes.« less

TerraSAR-X time-series interferometry detects human-induce subsidence in the Historical Centre of Hanoi, Vietnam

NASA Astrophysics Data System (ADS)

Le, Tuan; Chang, Chung-Pai; Nguyen, Xuan

2016-04-01

Hanoi was the capital of 12 Vietnamese dynasties, where the most historical relics, archaeological ruins and ancient monuments are located over Vietnam. However, those heritage assets are threatened by the land subsidence process occurred in recent decades, which mainly triggered by massive groundwater exploitation and construction activities. In this work, we use a set of high resolution TerraSAR-X images to map small-scale land subsidence patterns in the Historical Centre of Hanoi from April 2012 to November 2013. Images oversampling is integrated into the Small Baseline InSAR processing chain in order to enlarge the monitoring coverage by increasing the point-wise measurements, maintaining the monitoring scale of single building and monument. We analyzed over 2.4 million radar targets on 13.9 km2 area of interest based on 2 main sites: The Citadel, the Old Quarter and French Quarter. The highest subsidence rate recorded is -14.2 mm/year. Most of the heritage assets are considered as stable except the Roman Catholic Archdiocese and the Ceramic Mosaic Mural with the subsidence rates are -14.2 and -13.7 mm/year, respectively. Eventually, optical image and soil properties map are used to determine the causes of subsidence patterns. The result shows the strong relationships between the existing construction sites, the component of sediments and land subsidence processes that occurred in the study site.

THE ASTEROID BELT AS A RELIC FROM A CHAOTIC EARLY SOLAR SYSTEM

DOE Office of Scientific and Technical Information (OSTI.GOV)

Izidoro, André; Raymond, Sean N.; Pierens, Arnaud

The orbital structure of the asteroid belt holds a record of the solar system’s dynamical history. The current belt only contains ∼10{sup −3} Earth masses yet the asteroids’ orbits are dynamically excited, with a large spread in eccentricity and inclination. In the context of models of terrestrial planet formation, the belt may have been excited by Jupiter’s orbital migration. The terrestrial planets can also be reproduced without invoking a migrating Jupiter; however, as it requires a severe mass deficit beyond Earth’s orbit, this model systematically under-excites the asteroid belt. Here we show that the orbits of the asteroids may havemore » been excited to their current state if Jupiter’s and Saturn’s early orbits were chaotic. Stochastic variations in the gas giants’ orbits cause resonances to continually jump across the main belt and excite the asteroids’ orbits on a timescale of tens of millions of years. While hydrodynamical simulations show that the gas giants were likely in mean motion resonance at the end of the gaseous disk phase, small perturbations could have driven them into a chaotic but stable state. The gas giants’ current orbits were achieved later, during an instability in the outer solar system. Although it is well known that the present-day solar system exhibits chaotic behavior, our results suggest that the early solar system may also have been chaotic.« less

The Olsen Rotating Dipole, Revisited

NASA Astrophysics Data System (ADS)

Svalgaard, L.; Gough, D. O.; Scherrer, P. H.

2016-12-01

Olsen (1948) and Wilcox & Gonzales (1971) reported evidence of a solar equatorial magnetic dipole with a stable (synodic) rotation period of 26 7/8 days maintaining its phase over 15 years (1926-1941, Olsen) and possibly to 1968 as well (1963-1968, Wilcox & Gonzales). Using a composite series of Interplanetary Magnetic Sector Polarities covering the interval 1844-2016 (derived from geomagnetic data before the space age and direct measurements during 1963-2016) we find that 1) the response of geomagnetic activity to passage (at Earth) of a sector boundary has been consistently the same in every solar cycle from 9 through 24, thus validating the inferred times of sector boudary passages over the past 173 years, and 2) the 'Olsen' dipole can be traced back the 16 cycles to the year 1844, albeit with a slightly different synodic rotation period of 26.86 days (431 nHz). Olsen ended his paper with "The persistence of a fixed period during 15 years points to the possibility that the origin of the effect is to be found in a layer on the Sun with a fixed rotation-period during a long time" and Wilcox & Gonzales noted that "A rotating magnetic dipole may be lurking within the sun". We compare the Olsen-period with other evidence for rotation periods in the deep interior and for the existence of a relic magnetic field.

Unified scenario for composite right-handed neutrinos and dark matter

DOE Office of Scientific and Technical Information (OSTI.GOV)

Davoudiasl, Hooman; Giardino, Pier Paolo; Neil, Ethan T.

In this study, we entertain the possibility that neutrino masses and dark matter (DM) originate from a common composite dark sector. A minimal effective theory can be constructed based on a dark SU(3) D interaction with three flavors of massless dark quarks; electroweak symmetry breaking gives masses to the dark quarks. By assigning a Z 2 charge to one flavor, a stable “dark kaon” can provide a good thermal relic DM candidate. We find that “dark neutrons” may be identified as right handed Dirac neutrinos. Some level of “neutron-anti-neutron” oscillation in the dark sector can then result in non-zero Majoranamore » masses for light standard model neutrinos. A simple ultraviolet completion is presented, involving additional heavy SU(3) D-charged particles with electroweak and lepton Yukawa couplings. At our benchmark point, there are “dark pions” that are much lighter than the Higgs and we expect spectacular collider signals arising from the UV framework. This includes the decay of the Higgs boson to ττℓℓ', where ℓ(ℓ ') can be any lepton, with displaced vertices. Finally, we discuss the observational signatures of this UV framework in dark matter searches and primordial gravitational wave experiments; the latter signature is potentially correlated with the H → ττℓℓ' decay.« less

Phenomenology of U(1)F extension of inert-doublet model with exotic scalars and leptons

NASA Astrophysics Data System (ADS)

Dhargyal, Lobsang

2018-02-01

In this work we will extend the inert-doublet model (IDM) by adding a new U(1)F gauge symmetry to it, under which, a Z2 even scalar (φ 2) and Z2 odd right handed component of two exotic charged leptons (F_{eR}, F_{μ R}), are charged. We also add one Z2 even real scalar (φ 1) and one complex scalar (φ ), three neutral Majorana right handed fermions (N1, N2, N3), two left handed components of the exotic charged leptons (F_{eL}, F_{μ L}) as well as F_{τ } are all odd under the Z2, all of which are not charged under the U(1)F. With these new particles added to the IDM, we have a model which can give two scalar DM candidates, together they can explain the present DM relic density as well as the muon (g-2) anomaly simultaneously. Also in this model the neutrino masses are generated at one loop level. One of the most peculiar feature of this model is that non-trivial solution to the axial gauge anomaly free conditions lead to the prediction of a stable very heavy partner to the electron (Fe), whose present collider limit (13 TeV LHC) on its mass should be around m_{Fe} ≥ few TeV.

Heavy stable charged tracks as signatures of non-thermal dark matter at the LHC: a study in some non-supersymmetric scenarios

NASA Astrophysics Data System (ADS)

Ghosh, Avirup; Mondal, Tanmoy; Mukhopadhyaya, Biswarup

2017-12-01

We consider two theoretical scenarios, each including a ℤ 2-odd sector and leading to an elementary dark matter candidate. The first one is a variant of the Type-III seesaw model where one lepton triplet is ℤ 2-odd, together with a heavy sterile neutrino. It leads to a fermionic dark matter, together with the charged component of the triplet being a quasi-stable particle which decays only via a higher-dimensional operator suppressed by a high scale. The second model consists of an inert scalar doublet together with a ℤ 2-odd right-handed Majorana neutrino dark matter. A tiny Yukawa coupling delays the decay of the charged component of the inert doublet into the dark matter candidate, making the former long-lived on the scale of collider detectors. The parameter space of each model has been constrained by big-bang nucleosynthesis constraints, and also by estimating the contribution to the relic density through freeze-out of the long-lived charged particle as well the freeze-in production of the dark matter candidate. We consider two kinds of signals at the Large Hadron Collider for each case. For the first kind of models, namely two charged tracks and single track [InlineMediaObject not available: see fulltext.] and for the second kind, the characteristic signals are opposite as well as same-sign charged track pairs. We perform a detailed analysis using event selection criteria consistent with the current experimental programmes. It is found that the scenario with a lepton triplet can be probed upto 960 (1190) GeV with an integrated luminosity of 300 (3000) fb-1, while the corresponding numbers for the inert doublet scenario are 630 (800) GeV. Furthermore, the second kind of signal mentioned in each case allows us to differentiate different dark matter scenarios from each other.

The Pendulum in the 21st Century-Relic or Trendsetter

ERIC Educational Resources Information Center

Peters, Randall D.

2004-01-01

When identifying instruments that have had great influence on the history of physics, none comes to mind more quickly than the pendulum. Though first treated scientifically by Galileo in the 16th century, and in some respects nearly "dead" by the middle of the 20th century; the pendulum experienced "rebirth" by becoming an archetype of chaos. With…

Two-loop neutrino model with exotic leptons

NASA Astrophysics Data System (ADS)

Okada, Hiroshi; Orikasa, Yuta

2016-01-01

We propose a two-loop induced neutrino mass model, in which we show some bench mark points to satisfy the observed neutrino oscillation, the constraints of lepton flavor violations, and the relic density in the coannihilation system satisfying the current upper bound on the spin independent scattering cross section with nuclei. We also discuss new sources of muon anomalous magnetic moments.

Ancient DNA confirms native Rocky Mountain fisher (Martes pennanti) avoided early 20th century extinction

Treesearch

Michael K. Schwartz

2007-01-01

Until recently it was assumed that fishers (Martes pennanti) in the Rocky Mountains all were descended from reintroduced stocks. However, a recent study reported that mitochondrial DNA (cytochrome-b and control region) haplotypes of fishers found only in west-central Montana are likely derived from a relic population of fishers that escaped harvests conducted in the...

Thermal dark matter from a highly decoupled sector

DOE PAGES

Berlin, Asher; Hooper, Dan; Krnjaic, Gordan

2016-11-17

It has recently been shown that if the dark matter is in thermal equilibrium with a sector that is highly decoupled from the Standard Model, it can freeze out with an acceptable relic abundance, even if the dark matter is as heavy as ~1–100 PeV. In such scenarios, both the dark and visible sectors are populated after inflation, but with independent temperatures. The lightest particle in the dark sector will be generically long-lived and can come to dominate the energy density of the Universe. Upon decaying, these particles can significantly reheat the visible sector, diluting the abundance of dark mattermore » and thus allowing for dark matter particles that are much heavier than conventional WIMPs. In this study, we present a systematic and pedagogical treatment of the cosmological history in this class of models, emphasizing the simplest scenarios in which a dark matter candidate annihilates into hidden sector particles which then decay into visible matter through the vector, Higgs, or lepton portals. In each case, we find ample parameter space in which very heavy dark matter particles can provide an acceptable thermal relic abundance. We also discuss possible extensions of models featuring these dynamics.« less

Exact theory of freeze-out

NASA Astrophysics Data System (ADS)

Cannoni, Mirco

2015-03-01

We show that the standard theory of thermal production and chemical decoupling of WIMPs is incomplete. The hypothesis that WIMPs are produced and decouple from a thermal bath implies that the rate equation the bath particles interacting with the WIMPs is an algebraic equation that constraints the actual WIMPs abundance to have a precise analytical form down to the temperature . The point , which coincides with the stationary point of the equation for the quantity , is where the maximum departure of the WIMPs abundance from the thermal value is reached. For each mass and total annihilation cross section , the temperature and the actual WIMPs abundance are exactly known. This value provides the true initial condition for the usual differential equation that have to be integrated in the interval . The matching of the two abundances at is continuous and differentiable. The dependence of the present relic abundance on the abundance at an intermediate temperature is an exact result. The exact theory suggests a new analytical approximation that furnishes the relic abundance accurate at the level of 1-2 % in the case of -wave and -wave scattering cross sections. We conclude the paper studying the evolution of the WIMPs chemical potential and the entropy production using methods of non-equilibrium thermodynamics.

New viable region of an inert Higgs doublet dark matter model with scotogenic extension

NASA Astrophysics Data System (ADS)

Borah, Debasish; Gupta, Aritra

2017-12-01

We explore the intermediate dark matter mass regime of the inert Higgs doublet model, approximately between 400 and 550 GeV, which is allowed by latest constraints from direct and indirect detection experiments, but the thermal relic abundance remains suppressed. We extend the model by three copies of right-handed neutrinos, odd under the built-in Z2 symmetry of the model. This discrete Z2 symmetry of the model allows these right-handed neutrinos to couple to the usual lepton doublets through the inert Higgs doublet allowing the possibility of radiative neutrino mass in the scotogenic fashion. Apart from generating nonzero neutrino mass, such an extension can also revive the intermediate dark matter mass regime. The late decay of the lightest right-handed neutrino to dark matter makes it possible for the usual thermally underabundant dark matter in this intermediate mass regime to satisfy the correct relic abundance limit. The revival of this wide intermediate mass range can have relevance not only for direct and indirect search experiments but also for neutrino experiments as the long lifetime of the lightest right-handed neutrino also results in almost vanishing lightest neutrino mass.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bagherian, Z.; Ettefaghi, M.M.; Haghgouyan, Z.

We consider the standard model (SM) extended by a gauge singlet fermion as cold dark matter (SFCDM) and a gauge singlet scalar (singlet Higgs) as a mediator. The parameter space of the SM is enlarged by seven new ones. We obtain the total annihilation cross section of singlet fermions to the SM particles and singlet Higgs at tree level. Regarding the relic abundance constraint obtained by WMAP observations, we study the dependency on each parameter separately, for dark matter masses up to 1 TeV. In particular, the coupling of SFCDM to singlet Higgs g{sub s}, the SFCDM mass m{sub ψ},more » the second Higgs mass m{sub h{sub 2}}, and the Higgs bosons mixing angel θ are investigated accurately. Three other parameters play no significant role. For a maximal mixing of Higgs bosons or at resonances, g{sub s} is applicable for the perturbation theory at tree level. We also obtain the scattering cross section of SFCDM off nucleons and compare our results with experiments which have already reported data in this mass range; XENON100, LUX, COUPP and PICASSO collaborations. Our results show that the SFCDM is excluded by these experiments for choosing parameters which are consistent with perturbation theory and relic abundance constraints.« less

Featured Image: New Detail in the Toothbrush Cluster

NASA Astrophysics Data System (ADS)

Kohler, Susanna

2018-01-01

This spectacular composite (click here for the full image) reveals the galaxy cluster 1RXS J0603.3+4214, known as the Toothbrush cluster due to the shape of its most prominent radio relic. Featured in a recent publication led by Kamlesh Rajpurohit (Thuringian State Observatory, Germany), this image contains new Very Large Array (VLA) 1.5-GHz observations (red) showing the radio emission within the cluster. This is composited with a Chandra view of the X-ray emitting gas of the cluster (blue) and an optical image of the background from Subaru data. The new deep VLA data totaling 26 hours of observations provides a detailed look at the complex structure within the Toothbrush relic, revealing enigmatic filaments and twists (see below). This new data will help us to explore the possible merger history of this cluster, which is theorized to have caused the unusual shapes we see today. For more information, check out the original article linked below.High resolution VLA 12 GHz image of the Toothbrush showing the complex, often filamentary structures. [Rajpurohit et al. 2018]CitationK. Rajpurohit et al 2018 ApJ 852 65. doi:10.3847/1538-4357/aa9f13

Entropy Growth in the Early Universe and Confirmation of Initial Big Bang Conditions

NASA Astrophysics Data System (ADS)

Beckwith, Andrew

2009-09-01

This paper shows how increased entropy values from an initially low big bang level can be measured experimentally by counting relic gravitons. Furthermore the physical mechanism of this entropy increase is explained via analogies with early-universe phase transitions. The role of Jack Ng's (2007, 2008a, 2008b) revised infinite quantum statistics in the physics of gravitational wave detection is acknowledged. Ng's infinite quantum statistics can be used to show that ΔS~ΔNgravitons is a startmg point to the increasing net universe cosmological entropy. Finally, in a nod to similarities AS ZPE analysis, it is important to note that the resulting ΔS~ΔNgravitons ≠ 1088, that in fact it is much lower, allowing for evaluating initial graviton production as an emergent field phenomena, which may be similar to how ZPE states can be used to extract energy from a vacuum if entropy is not maximized. The rapid increase in entropy so alluded to without near sudden increases to 1088 may be enough to allow successful modeling of relic graviton production for entropy in a manner similar to ZPE energy extraction from a vacuum state.

Thermal dark matter from a highly decoupled sector

DOE Office of Scientific and Technical Information (OSTI.GOV)

Berlin, Asher; Hooper, Dan; Krnjaic, Gordan

It has recently been shown that if the dark matter is in thermal equilibrium with a sector that is highly decoupled from the Standard Model, it can freeze out with an acceptable relic abundance, even if the dark matter is as heavy as ~1–100 PeV. In such scenarios, both the dark and visible sectors are populated after inflation, but with independent temperatures. The lightest particle in the dark sector will be generically long-lived and can come to dominate the energy density of the Universe. Upon decaying, these particles can significantly reheat the visible sector, diluting the abundance of dark mattermore » and thus allowing for dark matter particles that are much heavier than conventional WIMPs. In this study, we present a systematic and pedagogical treatment of the cosmological history in this class of models, emphasizing the simplest scenarios in which a dark matter candidate annihilates into hidden sector particles which then decay into visible matter through the vector, Higgs, or lepton portals. In each case, we find ample parameter space in which very heavy dark matter particles can provide an acceptable thermal relic abundance. We also discuss possible extensions of models featuring these dynamics.« less

Implications of two-component dark matter induced by forbidden channels and thermal freeze-out

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aoki, Mayumi; Toma, Takashi, E-mail: mayumi@hep.s.kanazawa-u.ac.jp, E-mail: takashi.toma@tum.de

2017-01-01

We consider a model of two-component dark matter based on a hidden U(1) {sub D} symmetry, in which relic densities of the dark matter are determined by forbidden channels and thermal freeze-out. The hidden U(1) {sub D} symmetry is spontaneously broken to a residual Z{sub 4} symmetry, and the lightest Z{sub 4} charged particle can be a dark matter candidate. Moreover, depending on the mass hierarchy in the dark sector, we have two-component dark matter. We show that the relic density of the lighter dark matter component can be determined by forbidden annihilation channels which require larger couplings compared tomore » the normal freeze-out mechanism. As a result, a large self-interaction of the lighter dark matter component can be induced, which may solve small scale problems of ΛCDM model. On the other hand, the heavier dark matter component is produced by normal freeze-out mechanism. We find that interesting implications emerge between the two dark matter components in this framework. We explore detectabilities of these dark matter particles and show some parameter space can be tested by the SHiP experiment.« less

To assess the value of satellite photographs in resource evaluation on a national scale

NASA Technical Reports Server (NTRS)

Hepworth, J. V. (Principal Investigator); Akehurst, S. M.

1973-01-01

The author has identified the following significant results. Small scale ERTS-1 imagery has enabled investigators to study large areas at a time. The imagery appears to confirm a new theory that Archean greenstone belts in NE Botswanna and SW Rhodesia are co-extensive and that these so-called schist relics formerly covered a much wider area than is apparent now. The central parts of the region bounded by the schist relics are believed to have suffered granitization. A remnant of an older drainage system to the southwest of the Okavango Swamps, which seems to have been newly discovered on the imagery, may be an indication of the seismic instability of the region. Even quite small earth movements in the swamps could radically affect the direction of water flow. The imagery has proved successful in showing areas infested by the water weed Salvinia Auriculata in the Chobe and Zambesi rivers. This will be immensely valuable in later surveys on the ground. If the satellite was to have continued working, the imagery would have enabled workers to determine the extent of encroachment of the weed without recourse to field observations.

Strongly self-interacting vector dark matter via freeze-in

NASA Astrophysics Data System (ADS)

Duch, Mateusz; Grzadkowski, Bohdan; Huang, Da

2018-01-01

We study a vector dark matter (VDM) model in which the dark sector couples to the Standard Model sector via a Higgs portal. If the portal coupling is small enough the VDM can be produced via the freeze-in mechanism. It turns out that the electroweak phase transition have a substantial impact on the prediction of the VDM relic density. We further assume that the dark Higgs boson which gives the VDM mass is so light that it can induce strong VDM self-interactions and solve the small-scale structure problems of the Universe. As illustrated by the latest LUX data, the extreme smallness of the Higgs portal coupling required by the freeze-in mechanism implies that the dark matter direct detection bounds are easily satisfied. However, the model is well constrained by the indirect detections of VDM from BBN, CMB, AMS-02, and diffuse γ/X-rays. Consequently, only when the dark Higgs boson mass is at most of O (keV) does there exist a parameter region which leads to a right amount of VDM relic abundance and an appropriate VDM self-scattering while satisfying all other constraints simultaneously.

Electroweak baryogenesis and dark matter via a pseudoscalar vs. scalar

NASA Astrophysics Data System (ADS)

Ghorbani, Parsa Hossein

2017-08-01

We study the electroweak baryogenesis in a fermionic dark matter scenario with a (pseudo)scalar being the mediator in the Higgs portal. It is discussed that the electroweak phase transition turns to be first-order after taking into account the role of the (pseudo)scalar in the thermal effective potential in our extended standard model. Imposing the relic density constraint from the WMAP/Planck and the bounds from the direct detection experiments XENON100/LUX, we show that the dark matter scenario with a scalar mediator is hardly capable of explaining the baryogenesis while the same model with a pseudoscalar mediator is able to explain the baryon asymmetry. For the latter, we constrain more the model with Fermi-LAT upper limit on dark matter annihilation into b\\overline{b} and τ + τ -. The allowed dark matter mass that leads to correct relic abundance, renders the electroweak phase transition strongly first-order, and respects the Fermi-LAT limit, will be in the range 110-320 GeV. The exotic and invisible Higgs decay bounds and the mono-jet search limit at the LHC do not affect the viable space of parameters.

Top-philic dark matter within and beyond the WIMP paradigm

NASA Astrophysics Data System (ADS)

Garny, Mathias; Heisig, Jan; Hufnagel, Marco; Lülf, Benedikt

2018-04-01

We present a comprehensive analysis of top-philic Majorana dark matter that interacts via a colored t -channel mediator. Despite the simplicity of the model—introducing three parameters only—it provides an extremely rich phenomenology allowing us to accommodate the relic density for a large range of coupling strengths spanning over 6 orders of magnitude. This model features all "exceptional" mechanisms for dark matter freeze-out, including the recently discovered conversion-driven freeze-out mode, with interesting signatures of long-lived colored particles at colliders. We constrain the cosmologically allowed parameter space with current experimental limits from direct, indirect and collider searches, with special emphasis on light dark matter below the top mass. In particular, we explore the interplay between limits from Xenon1T, Fermi-LAT and AMS-02 as well as limits from stop, monojet and Higgs invisible decay searches at the LHC. We find that several blind spots for light dark matter evade current constraints. The region in parameter space where the relic density is set by the mechanism of conversion-driven freeze-out can be conclusively tested by R -hadron searches at the LHC with 300 fb-1 .

Anatomy of the inert two-Higgs-doublet model in the light of the LHC and non-LHC dark matter searches

NASA Astrophysics Data System (ADS)

Belyaev, Alexander; Cacciapaglia, Giacomo; Ivanov, Igor P.; Rojas-Abatte, Felipe; Thomas, Marc

2018-02-01

The inert two-Higgs-doublet model (i2HDM) is a theoretically well-motivated example of a minimal consistent dark matter (DM) model which provides monojet, mono-Z , mono-Higgs, and vector-boson-fusion +ETmiss signatures at the LHC, complemented by signals in direct and indirect DM search experiments. In this paper we have performed a detailed analysis of the constraints in the full five-dimensional parameter space of the i2HDM, coming from perturbativity, unitarity, electroweak precision data, Higgs data from the LHC, DM relic density, direct/indirect DM detection, and LHC monojet analysis, as well as implications of experimental LHC studies on disappearing charged tracks relevant to a high DM mass region. We demonstrate the complementarity of the above constraints and present projections for future LHC data and direct DM detection experiments to probe further i2HDM parameter space. The model is implemented into the CalcHEP and micrOMEGAs packages, which are publicly available at the HEPMDB database, and it is ready for a further exploration in the context of the LHC, relic density, and DM direct detection.

D-brane disformal coupling and thermal dark matter

NASA Astrophysics Data System (ADS)

Dutta, Bhaskar; Jimenez, Esteban; Zavala, Ivonne

2017-11-01

Conformal and disformal couplings between a scalar field and matter occur naturally in general scalar-tensor theories. In D-brane models of cosmology and particle physics, these couplings originate from the D-brane action describing the dynamics of its transverse (the scalar) and longitudinal (matter) fluctuations, which are thus coupled. During the post-inflationary regime and before the onset of big bang nucleosynthesis (BBN), these couplings can modify the expansion rate felt by matter, changing the predictions for the thermal relic abundance of dark matter particles and thus the annihilation rate required to satisfy the dark matter content today. We study the D-brane-like conformal and disformal couplings effect on the expansion rate of the Universe prior to BBN and its impact on the dark matter relic abundance and annihilation rate. For a purely disformal coupling, the expansion rate is always enhanced with respect to the standard one. This gives rise to larger cross sections when compared to the standard thermal prediction for a range of dark matter masses, which will be probed by future experiments. In a D-brane-like scenario, the scale at which the expansion rate enhancement occurs depends on the string coupling and the string scale.

Inflation and shadow matter

NASA Technical Reports Server (NTRS)

Krauss, L. M.; Guth, A. H.; Spergel, D. N.; Field, G. B.; Press, W. H.

1986-01-01

The possible production of shadow matter during the period of cosmic inflation is considered. The superstring theory of Gross et al. (1985), which results in a gauge group E8 x E8, could, at low energies, result in the existence of two sectors: an observed sector associated with all familiar particles and interactions, and a hidden one whose particles couple only through gravitational interactions with ordinary matter. It is demonstrated here that if, in the early universe, an inflationary phase is associated with the breaking of one of the symmetries in the E8 x E8 theory, this strongly constrains the physics of both sectors if shadow matter is to be the missing mass in the universe.

Radiative Kähler moduli stabilization

NASA Astrophysics Data System (ADS)

Kobayashi, Tatsuo; Omoto, Naoya; Otsuka, Hajime; Tatsuishi, Takuya H.

2018-05-01

We propose a new type of Kähler moduli stabilization mechanisms in type IIB superstring theory on Calabi-Yau manifolds with the positive Euler number. The overall Kähler modulus can be perturbatively stabilized by radiative corrections due to sparticles. Its minimum is the anti-de Sitter vacuum, where supersymmetry is broken. We can uplift it to the de Sitter vacuum by introducing anti-D-branes, keeping the modulus stabilized. Although our numerical results depend on the choice of the cutoff scale and degeneracies of sparticles, at any rate there exist the parameter spaces where the masses of Kaluza-Klein and stringy modes are larger than the cutoff scale. Furthermore, this stabilization scenario predicts an ultralight axion.

Superstrate sub-cell voltage-matched multijunction solar cells

DOEpatents

Mascarenhas, Angelo; Alberi, Kirstin

2016-03-15

Voltage-matched thin film multijunction solar cell and methods of producing cells having upper CdTe pn junction layers formed on a transparent substrate which in the completed device is operatively positioned in a superstate configuration. The solar cell also includes a lower pn junction formed independently of the CdTe pn junction and an insulating layer between CdTe and lower pn junctions. The voltage-matched thin film multijunction solar cells further include a parallel connection between the CdTe pn junction and lower pn junctions to form a two-terminal photonic device. Methods of fabricating devices from independently produced upper CdTe junction layers and lower junction layers are also disclosed.

Supersymmetry, Supergravity, and Unification

NASA Astrophysics Data System (ADS)

Nath, Pran

2016-12-01

Dedication; Preface; 1. A brief history of unification; 2. Gravitation; 3. Non-abelian gauge theory; 4. Spontaneous breaking of global and local symmetries; 5. The Standard Model; 6. Anomalies; 7. Effective Lagrangians; 8. Supersymmetry; 9. Grand unification; 10. MSSM Lagrangian; 11. N = 1 supergravity; 12. Coupling of supergravity with matter and gauge fields; 13. Supergravity grand unification; 14. Phenomenology of supergravity grand unification; 15. CP violation in supergravity unified theories; 16. Proton stability in supergravity unified theories; 17. Cosmology, astroparticle physics and SUGRA unification; 18. Extended supergravities and supergravities from superstrings; 19. Specialized topics; 20. The future of unification; 21. Appendices; 22. Notations, conventions, and formulae; 23. Physical constants; 24. List of books and reviews for further reading; Index.

Transmogrifying fuzzy vortices

NASA Astrophysics Data System (ADS)

Murugan, Jeff; Millner, Antony

2004-04-01

We show that the construction of vortex solitons of the noncommutative abelian-Higgs model can be extended to a critically coupled gauged linear sigma model with Fayet-Illiopolous D-terms. Like its commutative counterpart, this fuzzy linear sigma model has a rich spectrum of BPS solutions. We offer an explicit construction of the degree-k static semilocal vortex and study in some detail the infinite coupling limit in which it descends to a degree-k Bbb CBbb PkN instanton. This relation between the fuzzy vortex and noncommutative lump is used to suggest an interpretation of the noncommutative sigma model soliton as tilted D-strings stretched between an NS5-brane and a stack of D3-branes in type-IIB superstring theory.

μ-near-zero metamaterial slabs for a new concept of plasmonic sensing platforms

NASA Astrophysics Data System (ADS)

Girón-Sedas, J. A.; Oliveira, Osvaldo N.; Mejía-Salazar, J. R.

2018-05-01

We demonstrate that the excitation of magnetic bulk plasmon-like resonances in μ-near-zero double-negative metamaterial slabs is suitable for the design of new sensing platforms, where light-to-plasmon coupling is reached without requiring a prism or grating coupler. This allows for excitation with light coming directly from the air and for dielectric substrates with any refractive index. In the microwave region this architecture is able to detect changes as small as 10-2 in the refractive index of the superstrate. If the metamaterial slab is backed by a metallic substrate, on the other hand, the system can be used as a light-absorber for light harvesting applications.

Development of new EVA formulations for improved performance at NREL

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pern, F.J.

1997-02-01

We review in chronological order the research stages and fundamental concepts involved in developing modified and new EVA formulations for improved performance against photo-induced degradation and discoloration. The new NREL EVA formulations use additives totally different from the present commercial formulations (EVA A9918 and EVA 15295). Validation of their long-term photostability and thermostability is presently under way. Together with UV-absorbing glass superstrates, they may offer better success in achieving a more reliable module performance and longer service life without significant EVA discoloration problems, which are commonly experienced with EVA A9918 and, at a lesser rate, EVA 15295. {copyright} {ital 1997more » American Institute of Physics.}« less

micrOMEGAs 2.0.7: a program to calculate the relic density of dark matter in a generic model

NASA Astrophysics Data System (ADS)

Bélanger, G.; Boudjema, F.; Pukhov, A.; Semenov, A.

2007-12-01

micrOMEGAs2.0.7 is a code which calculates the relic density of a stable massive particle in an arbitrary model. The underlying assumption is that there is a conservation law like R-parity in supersymmetry which guarantees the stability of the lightest odd particle. The new physics model must be incorporated in the notation of CalcHEP, a package for the automatic generation of squared matrix elements. Once this is done, all annihilation and coannihilation channels are included automatically in any model. Cross-sections at v=0, relevant for indirect detection of dark matter, are also computed automatically. The package includes three sample models: the minimal supersymmetric standard model (MSSM), the MSSM with complex phases and the NMSSM. Extension to other models, including non supersymmetric models, is described. Program summaryTitle of program:micrOMEGAs2.0.7 Catalogue identifier:ADQR_v2_1 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/ADQR_v2_1.html Program obtainable from: CPC Program Library, Queen's University of 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.:216 529 No. of bytes in distributed program, including test data, etc.:1 848 816 Distribution format:tar.gz Programming language used:C and Fortran Computer:PC, Alpha, Mac, Sun Operating system:UNIX (Linux, OSF1, SunOS, Darwin, Cygwin) RAM:17 MB depending on the number of processes required Classification:1.9, 11.6 Catalogue identifier of previous version:ADQR_v2_0 Journal version of previous version:Comput. Phys. Comm. 176 (2007) 367 Does the new version supersede the previous version?:Yes Nature of problem:Calculation of the relic density of the lightest stable particle in a generic new model of particle physics. Solution method:In numerically solving the evolution equation for the density of dark matter, relativistic formulae for the thermal average are used. All tree-level processes for annihilation and coannihilation of new particles in the model are included. The cross-sections for all processes are calculated exactly with CalcHEP after definition of a model file. Higher-order QCD corrections to Higgs couplings to quark pairs are included. Reasons for new version:The main changes in this new version consist, on the one hand, in improvements of the user interface and treatment of error codes when using spectrum calculators in the MSSM and, on the other hand, on a completely revised code for the calculation of the relic density in the NMSSM based on the code NMSSMTools1.0.2 for the computation of the spectrum. Summary of revisions:The version of CalcHEP was updated to CalcHEP 2.4. The procedure for shared library generation has been improved. Now the libraries are recalculated each time the model is modified. The default value for the top quark mass has been set to 171.4 GeV. Changes specific to the MSSM model. The deltaMb correction is now included in the B,t,H-vertex and is always included for other Higgs vertices. In case of a fatal error in an RGE program, micrOMEGAs now continues operation while issuing a warning that the given point is not valid. This is important when running scans over parameter space. However this means that the standard ˆC command that could be used to cancel a job now only cancels the RGE program. To cancel a job, use "kill -9 -N" where N is the micrOMEGAs process id, all child processes launched by micrOMEGAs will be killed at once. Following the last SLHA2 release, we use key=26 item of EXTPAR block for the pole mass of the CP-odd Higgs so that micrOMEGAs can now use SoftSUSY for spectrum calculation with EWSB input. The Isajet interface was corrected too, so the user has to recompile the isajet_slha executable. For SuSpect we still support an old "wrong" interface where key=24 is used for the mass of the CP-odd Higgs. In the non-universal SUGRA model, we set the value of M ( M,A) to the value of the largest subset of equal parameters among scalar masses (gaugino masses, trilinear couplings). In the previous version these parameters were set arbitrarily to be equal to MH2, MG2 and At respectively. The spectrum calculators need an input value for M,M and A for initialisation purposes. We have removed bugs in micrOMEGAs-Isajet interface in case of non-universal SUGRA. $(FFLAGS) is added to compilation instruction of suspect.exe. It was omitted in version 2.0. The treatment of errors in reading of the LesHouches accord file is improved. Now, if the SPINFO block is absent in the SLHA output it is considered as a fatal error. Instructions for calculation of Δ, (, Br(b→sγ) and Br(B→μμ) constraints are included in EWSB sample main programs omg.c/omg.cpp/omg.F. We have corrected the name of the library for neutralino-neutralino annihilation in our sample files MSSM/cs br.*. Changes specific to the NMSSM model. The NMSSM has been completely revised. Now it is based on NMSSMTools_1.0.2. The deltaMb corrections in the NMSSM are included in the Higgs potential. CP violation model. We have included in our package the MSSM with CP violation. Our implementation was described in Phys. Rev. D 73 (2006) 115007. It is based on the CPSUPERH package published in Comput. Phys. Comm. 156 (2004) 283. Unusual features:Depending on the parameters of the model, the program generates additional new code, compiles it and loads it dynamically. Running time:0.2 seconds

Historical overview of nontimber forest product uses in the Northeastern United States

Treesearch

Marla R. Emery

2002-01-01

Nontimber forest product (NTFP) uses in the United States are neither new nor merely quaint relics of some distant cultural and economic past. As the other chapters in this book make clear, there is a plethora of NTFPs in use at the beginning of the twenty-first century. They contribute to the livelihoods of individuals from diverse ethnic backgrounds in a variety of...

The mysterious demise of an ice-age relic: exposing the cause of yellow-cedar decline.

Treesearch

Jonathan Thompson

2007-01-01

For more than a century, yellow-cedar has been inexplicably dying throughout the northern coastal rain forests of the Pacific Northwest. Yellow-cedar mortality has been mapped on more than a half million acres in southeastern Alaska, yet until recently the cause of death was a stubborn mystery. Researchers are hopeful, after several decades of investigation, that they...

Geophysical anomalies and quartz microstructures, Eastern Warburton Basin, North-east South Australia: Tectonic or impact shock metamorphic origin?

NASA Astrophysics Data System (ADS)

Glikson, Andrew Y.; Uysal, I. Tonguç; Fitz Gerald, John D.; Saygin, Erdinc

2013-03-01

The Eastern Warburton Basin, Northeast South Australia, features major geophysical anomalies, including a magnetic high of near-200 nT centred on a 25 km-wide magnetic low (< 100 nT), interpreted in terms of a magmatic body below 6 km depth. A distinct seismic tomographic low velocity anomaly may reflect its thick (9.5 km) sedimentary section, high temperatures and possible deep fracturing. Scanning electron microscope (SEM) analyses of granites resolves microbreccia veins consisting of micron-scale particles injected into resorbed quartz grains. Planar and sub-planar elements in quartz grains (Qz/PE) occur in granites, volcanics and sediments of the > 30,000 km-large Eastern Warburton Basin. The Qz/PE include multiple intersecting planar to curved sub-planar elements with relic lamellae less than 2 μm wide with spacing of 4-5 μm. Qz/PE are commonly re-deformed, displaying bent and wavy patterns accompanied with fluid inclusions. U-stage measurements of a total of 243 planar sets in 157 quartz grains indicate dominance of ∏{10-12}, ω{10-13} and subsidiary §{11-22}, {22-41}, m{10-11} and x{51-61} planes. Transmission Electron Microscopy (TEM) analysis displays relic narrow ≤ 1 μm-wide lamellae and relic non-sub grain boundaries where crystal segments maintain optical continuity. Extensive sericite alteration of feldspar suggests hydrothermal alteration to a depth of 500 m below the unconformity which overlies the Qz/PE-bearing Warburton Basin terrain. The data are discussed in terms of (A) Tectonic-metamorphic deformation and (B) impact shock metamorphism producing planar deformation features (Qz/PDF). Deformed Qz/PE are compared to re-deformed Qz/PDFs in the Sudbury, Vredefort, Manicouagan and Charlevoix impact structures. A 4-5 km uplift of the Big Lake Granite Suite during 298-295 Ma is consistent with missing of upper Ordovician to Devonian strata and possible impact rebound. The occurrence of circular seismic tomography anomalies below the east Warburton Basin, the Poolowana Basin and the Woodleigh impact structure signifies a potential diagnostic nature of circular tomographic anomalies.

Evaluation of Earth's Geobiosphere Emergy Baseline and the Emergy of Crustal Cycling

NASA Astrophysics Data System (ADS)

De Vilbiss, Chris

This dissertation quantitatively analyzed the exergy supporting the nucleosynthesis of the heavy isotopes, Earth's geobiosphere, and its crustal cycling. Exergy is that portion of energy that is available to drive work. The exergy sources that drive the geobiosphere are sunlight, Earth's rotational kinetic energy and relic heat, and radionuclides in Earth's interior. These four exergy sources were used to compute the Earth's geobiosphere emergy baseline (GEB), expressed as a single unit, solar equivalent joules (seJ). The seJ of radionuclides were computed by determining the quantity of gravitational exergy that dissipated in the production of both sunlight and heavy isotopes. This is a new method of computing solar equivalences also was applied to Earth's relic heat and rotational energy. The equivalent quantities of these four exergy sources were then added to express the GEB. This new baseline was compared with several other contemporary GEB methods. The new GEB is modeled as the support to Earth's crustal cycle and ultimately to the economical mineral deposits used in the US economy. Given the average annual cycling of crustal material and its average composition, specific emergies were calculated to express the average emergy per mass of particular crustal minerals. Chemical exergies of the minerals were used to develop transformities and specific emergies of minerals at heightened concentrations, i.e. minable concentrations. The effect of these new mineral emergy values were examined using the US economy as an example. The final result is an 83% reduction in the emergy of limestone, a 91% reduction in the aggregated emergy of all other minerals, and a 23% reduction in the emergy of the US economy. This dissertation explored three unique and innovative methods to compute the emergy of Earth's exergy sources and resources. First was a method for computing the emergy of radionuclides. Second was a method to evaluate the Earth's relic heat and dissipation of gravitational exergy that uses forward computation. Third is a more consistent method to compute the emergy value of crustal minerals based on their chemical exergy.

The zero-action hypothesis and high-temperature thermodynamics in the heterotic superstring theory

NASA Astrophysics Data System (ADS)

Pollock, M. D.

2005-07-01

The effective action S for the Einstein theory of gravity coupled to massless scalar fields phi, spinor fields ψ and gauge vector fields Fij describing radiation, so that FijFij = 0, vanishes identically after substitution from the classical equations of motion, thus allowing a perfect fluid for which the energy density ρ and pressure p = (γ - 1)ρ are related by values of the adiabatic index throughout the range 4/3 <= γ <= 2. In the heterotic superstring theory, four-point gravitational interactions generate a tree-level quadratic, higher-derivative contribution to the Lagrangian, after reduction to four dimensions, whose form, unchanged at one-loop level, is {\\cal R}^2 = B(R^2 -R_{ij}R^{ij}) = {1 \\over 6} B (\\gamma-2)(\\gamma-1) \\kappa^4 \\rho^2 , where the constant B ap 1 for a three-generation Calabi Yau manifold, and which thus constitutes a type of anomaly. The zero-action hypothesis requires the theory to be free of such anomalies, and thus predicts that the Universe started off in the state p = ρ discussed by Zel'dovich, characterized by the maximum value γ = 2 consistent with causality. Applying classical thermodynamics to a perfect fluid, we find that ρ, p and hence also the Helmholtz free-energy density f ≡ -p, scale with temperature as Tγ/γ-1, leading to the prediction that f ~ T2, which is exactly verified by the calculation of Atick and Witten, valid at genus-one in the high-temperature limit T Gt TH, after Euclideanizing the time coordinate, where TH is the Hagedorn temperature. The response of the action to the operators T, C and P is also discussed, T-invariance requiring γ = 2 and hence S = 0, and P-invariance requiring S = 0, showing that the zero-action hypothesis can be understood in terms of these discrete symmetries.

Suppressed supersymmetry breaking terms in the Higgs sector

NASA Astrophysics Data System (ADS)

Terao, Haruhiko; Kobayashi, Tatsuo

2004-07-01

We study the little hierarchy between mass parameters in the Higgs sector and other SUSY breaking masses. This type of spectrum can relieve the fine-tuning problem in the MSSM Higgs sector. Our scenario can be realized by superconformal dynamics. The spectrum in our scenario has significant implications in other phenomenological aspects like the relic abundance of the lightest neutralino and relaxation of the unbounded-from-below constraints.

Constraining unparticle physics with cosmology and astrophysics.

PubMed

Davoudiasl, Hooman

2007-10-05

It has recently been suggested that a scale-invariant "unparticle" sector with a nontrivial infrared fixed point may couple to the standard model (SM) via higher-dimensional operators. The weakness of such interactions hides the unparticle phenomena at low energies. We demonstrate how cosmology and astrophysics can place significant bounds on the strength of unparticle-SM interactions. We also discuss the possibility of a having a non-negligible unparticle relic density today.

The United States Army Battalion Surgeon: Frontline Requirement or Relic of a Bygone Era?

DTIC Science & Technology

2009-12-11

Battalion Aid Station BN Battalion BS Battalion Surgeon CBMM Core Battalion Medical Mission DOW Died of Wounds FSO Full Spectrum Operations GMO ...General Medical Officers or GMOs . Young, motivated, and greedy for knowledge, GMOs propelled the field of military medicine forward during...peacetime through analysis, research, and innovation. Their treated populations were small and exceedingly healthy. GMOs had no mission to treat dependents

Non-Gaussianity from self-ordering scalar fields

DOE Office of Scientific and Technical Information (OSTI.GOV)

Figueroa, Daniel G.; Instituto de Fisica Teorica UAM/CSIC, Universidad Autonoma de Madrid, 28049 Madrid; Caldwell, Robert R.

The Universe may harbor relics of the post-inflationary epoch in the form of a network of self-ordered scalar fields. Such fossils, while consistent with current cosmological data at trace levels, may leave too weak an imprint on the cosmic microwave background and the large-scale distribution of matter to allow for direct detection. The non-Gaussian statistics of the density perturbations induced by these fields, however, permit a direct means to probe for these relics. Here we calculate the bispectrum that arises in models of self-ordered scalar fields. We find a compact analytic expression for the bispectrum, evaluate it numerically, and providemore » a simple approximation that may be useful for data analysis. The bispectrum is largest for triangles that are aligned (have edges k{sub 1{approx_equal}}2k{sub 2{approx_equal}}2k{sub 3}) as opposed to the local-model bispectrum, which peaks for squeezed triangles (k{sub 1{approx_equal}}k{sub 2}>>k{sub 3}), and the equilateral bispectrum, which peaks at k{sub 1{approx_equal}}k{sub 2{approx_equal}}k{sub 3}. We estimate that this non-Gaussianity should be detectable by the Planck satellite if the contribution from self-ordering scalar fields to primordial perturbations is near the current upper limit.« less

Sri Dalada Maligawa - 3D-Scanning and Documentation of the Temple of the Sacred Tooth Relic at Kandy, Sri Lanka

NASA Astrophysics Data System (ADS)

Rahrig, M.; Luib, A.

2017-08-01

Sri Dalada Maligawa - the Temple of the Sacred Tooth Relic - is one of the most important pilgrim sites in Buddhist culture. It is the main part of the UNESCO World Heritage Site Sacred City of Kandy. Since the end of the 17th century the temple has been keeping the sacred tooth of the Buddha. Until now an accurate documentation of the temple with all its rich decorations is missing. The Temple is built in an area vulnerable to environmental factors like earthquakes or monsoon rains and was the target of terrorist attacks. To help preserving this important cultural heritage a research project was carried out. Main part of the project was a 3D-documentation of the entire temple by using Terrestrial-Laser-Scanning (TLS) and the creating of CAD-Plans. In addition to the documentation of the architecture several details were taken in high resolution by Structured-Light-Scanning (SLS). All data will be part of the digital archive of the temple and were used as a base for a general site monitoring, especially to observe cracks. Next to the mere documentation a transfer of knowledge was another aim of the project. In future most of the analysis of the scan data can be done by local specialists.

Windows on Our Universe: Breakthroughs in Observational Cosmology

NASA Astrophysics Data System (ADS)

Ruhl, John; Faber, Sandy; Weinberg, David

2009-03-01

Clusters and Cosmology with the South Pole Telescope[0pt] John Ruhl, Case Western Reserve University[4pt] The Formation of Galaxies[0pt] Sandra Faber, University of California, Santa Cruz[4pt] Cosmology from the Sloan Digital Sky Survey[0pt] David Weinberg, The Ohio State University[4pt] In the past decade, the study of our Universe has entered a data- driven era. Indeed, observational advances indicate that cosmologists can understand the evolution of our Universe in exquisite detail and use our Universe as a laboratory with which to make profound statements about the laws of physics. Cosmologists have mapped out the relic radiation from the big bang itself and have succeeded in enormous projects to map the patterns of galaxies and the evolution of galaxies over ten billion years. Researchers are beginning to understand how the initial conditions depicted in the relic radiation evolve to form such rich galactic structure. And of course, with new data new mysteries have arisen that strike at the heart of fundamental physics and drive another generation of ambitious observational projects. The three speakers will discuss recent breakthroughs in observational cosmology: what has been learned about our Universe, the mysteries that have been uncovered, and what they see for the future.

A dark matter model that reconciles tensions between the cosmic-ray e± excess and the gamma-ray and CMB constraints

NASA Astrophysics Data System (ADS)

Xiang, Qian-Fei; Bi, Xiao-Jun; Lin, Su-Jie; Yin, Peng-Fei

2017-10-01

The cosmic-ray (CR) e± excess observed by AMS-02 can be explained by dark matter (DM) annihilation. However, the DM explanation requires a large annihilation cross section which is strongly disfavored by other observations, such as the Fermi-LAT gamma-ray observation of dwarf galaxies and the Planck observation of the cosmic microwave background (CMB). Moreover, the DM annihilation cross section required by the CR e± excess is also too large to generate the correct DM relic density with thermal production. In this work we use the Breit-Wigner mechanism with a velocity dependent DM annihilation cross section to reconcile these tensions. If DM particles accounting for the CR e± excess with v ∼ O (10-3) are very close to a resonance in the physical pole case, their annihilation cross section in the Galaxy reaches a maximal value. On the other hand, the annihilation cross section would be suppressed for DM particles with smaller relative velocities in dwarf galaxies and at recombination, which may affect the gamma-ray and CMB observations, respectively. We find a proper parameter region that can simultaneously explain the AMS-02 results and the thermal relic density, while satisfying the Fermi-LAT and Planck constraints.

Primordial alchemy: from the Big Bang to the present universe

NASA Astrophysics Data System (ADS)

Steigman, Gary

Of the light nuclides observed in the universe today, D, 3He, 4He, and 7Li are relics from its early evolution. The primordial abundances of these relics, produced via Big Bang Nucleosynthesis (BBN) during the first half hour of the evolution of the universe provide a unique window on Physics and Cosmology at redshifts ~1010. Comparing the BBN-predicted abundances with those inferred from observational data tests the consistency of the standard cosmological model over ten orders of magnitude in redshift, constrains the baryon and other particle content of the universe, and probes both Physics and Cosmology beyond the current standard models. These lectures are intended to introduce students, both of theory and observation, to those aspects of the evolution of the universe relevant to the production and evolution of the light nuclides from the Big Bang to the present. The current observational data is reviewed and compared with the BBN predictions and the implications for cosmology (e.g., universal baryon density) and particle physics (e.g., relativistic energy density) are discussed. While this comparison reveals the stunning success of the standard model(s), there are currently some challenge which leave open the door for more theoretical and observational work with potential implications for astronomy, cosmology, and particle physics.

Testing cosmic ray acceleration with radio relics: a high-resolution study using MHD and tracers

NASA Astrophysics Data System (ADS)

Wittor, D.; Vazza, F.; Brüggen, M.

2017-02-01

Weak shocks in the intracluster medium may accelerate cosmic-ray protons and cosmic-ray electrons differently depending on the angle between the upstream magnetic field and the shock normal. In this work, we investigate how shock obliquity affects the production of cosmic rays in high-resolution simulations of galaxy clusters. For this purpose, we performed a magnetohydrodynamical simulation of a galaxy cluster using the mesh refinement code ENZO. We use Lagrangian tracers to follow the properties of the thermal gas, the cosmic rays and the magnetic fields over time. We tested a number of different acceleration scenarios by varying the obliquity-dependent acceleration efficiencies of protons and electrons, and by examining the resulting hadronic γ-ray and radio emission. We find that the radio emission does not change significantly if only quasi-perpendicular shocks are able to accelerate cosmic-ray electrons. Our analysis suggests that radio-emitting electrons found in relics have been typically shocked many times before z = 0. On the other hand, the hadronic γ-ray emission from clusters is found to decrease significantly if only quasi-parallel shocks are allowed to accelerate cosmic ray protons. This might reduce the tension with the low upper limits on γ-ray emission from clusters set by the Fermi satellite.

Cosmological Evolution of Massive Black Holes: Effects of Eddington Ratio Distribution and Quasar Lifetime

NASA Astrophysics Data System (ADS)

Cao, Xinwu

2010-12-01

A power-law time-dependent light curve for active galactic nuclei (AGNs) is expected by the self-regulated black hole growth scenario, in which the feedback of AGNs expels gas and shut down accretion. This is also supported by the observed power-law Eddington ratio distribution of AGNs. At high redshifts, the AGN life timescale is comparable with (or even shorter than) the age of the universe, which sets a constraint on the minimal Eddington ratio for AGNs on the assumption of a power-law AGN light curve. The black hole mass function (BHMF) of AGN relics is calculated by integrating the continuity equation of massive black hole number density on the assumption of the growth of massive black holes being dominated by mass accretion with a power-law Eddington ratio distribution for AGNs. The derived BHMF of AGN relics at z = 0 can fit the measured local mass function of the massive black holes in galaxies quite well, provided the radiative efficiency ~0.1 and a suitable power-law index for the Eddington ratio distribution are adopted. In our calculations of the black hole evolution, the duty cycle of AGN should be less than unity, which requires the quasar life timescale τQ >~ 5 × 108 years.

Fermionic dark matter with pseudo-scalar Yukawa interaction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ghorbani, Karim, E-mail: k-ghorbani@araku.ac.ir

2015-01-01

We consider a renormalizable extension of the standard model whose fermionic dark matter (DM) candidate interacts with a real singlet pseudo-scalar via a pseudo-scalar Yukawa term while we assume that the full Lagrangian is CP-conserved in the classical level. When the pseudo-scalar boson develops a non-zero vacuum expectation value, spontaneous CP-violation occurs and this provides a CP-violated interaction of the dark sector with the SM particles through mixing between the Higgs-like boson and the SM-like Higgs boson. This scenario suggests a minimal number of free parameters. Focusing mainly on the indirect detection observables, we calculate the dark matter annihilation crossmore » section and then compute the DM relic density in the range up to m{sub DM} = 300 GeV.We then find viable regions in the parameter space constrained by the observed DM relic abundance as well as invisible Higgs decay width in the light of 125 GeV Higgs discovery at the LHC. We find that within the constrained region of the parameter space, there exists a model with dark matter mass m{sub DM} ∼ 38 GeV annihilating predominantly into b quarks, which can explain the Fermi-LAT galactic gamma-ray excess.« less

Calculation of the local density of relic neutrinos

DOE Office of Scientific and Technical Information (OSTI.GOV)

De Salas, P.F.; Gariazzo, S.; Pastor, S.

2017-09-01

Nonzero neutrino masses are required by the existence of flavour oscillations, with values of the order of at least 50 meV . We consider the gravitational clustering of relic neutrinos within the Milky Way, and used the N -one-body simulation technique to compute their density enhancement factor in the neighbourhood of the Earth with respect to the average cosmic density. Compared to previous similar studies, we pushed the simulation down to smaller neutrino masses, and included an improved treatment of the baryonic and dark matter distributions in the Milky Way. Our results are important for future experiments aiming at detectingmore » the cosmic neutrino background, such as the Princeton Tritium Observatory for Light, Early-universe, Massive-neutrino Yield (PTOLEMY) proposal. We calculate the impact of neutrino clustering in the Milky Way on the expected event rate for a PTOLEMY-like experiment. We find that the effect of clustering remains negligible for the minimal normal hierarchy scenario, while it enhances the event rate by 10 to 20% (resp. a factor 1.7 to 2.5) for the minimal inverted hierarchy scenario (resp. a degenerate scenario with 150 meV masses). Finally we compute the impact on the event rate of a possible fourth sterile neutrino with a mass of 1.3 eV.« less

Understanding the radio spectral indices of galaxy cluster relics by superdiffusive shock acceleration

NASA Astrophysics Data System (ADS)

Zimbardo, Gaetano; Perri, Silvia

2018-06-01

Galaxy cluster merger shocks are the likely source of relativistic electrons, but many observations do not fit into the standard acceleration models. In particular, there is a long-standing discrepancy between the radio derived Mach numbers M_radio and the Mach numbers derived from X-ray measurements, M_X. Here, we show how superdiffusive electron transport and superdiffusive shock acceleration (SSA) can help to solve this problem. We present a heuristic derivation of the superlinear time growth of the mean square displacement of particles, ⟨Δx2⟩∝tβ, and of the particle energy spectral index in the framework of SSA. The resulting expression for the radio spectral index α is then used to determine the superdiffusive exponent β from the observed values of α and of the compression ratio for a number of radio relics. Therefore, the fact that M_radio>M_X can be explained by SSA without the need to make assumptions on the energy spectrum of the seed electrons to be re-accelerated. We also consider the acceleration times obtained in the diffusive case, based both on the Bohm diffusion coefficient and on the quasilinear diffusion coefficient. While in the latter case the acceleration time is consistent with the estimated electron energy loss time, the former case it is much shorter.

Thin-film module circuit design: Practical and reliability aspects

NASA Technical Reports Server (NTRS)

Daiello, R. V.; Twesme, E. N.

1985-01-01

This paper will address several aspects of the design and construction of submodules based on thin film amorphous silicon (a-Si) p i n solar cells. Starting from presently attainable single cell characteristics, and a realistic set of specifications, practical module designs are discussed from the viewpoints of efficient designs, the fabrication requirements, and reliability concerns. The examples center mostly on series interconnected modules of the superstrate type with detailed discussions of each portion of the structure in relation to its influence on module efficiency. Emphasis is placed on engineering topics such as: area coverage, optimal geometries, and cost and reliability. Practical constraints on achieving optimal designs, along with some examples of potential pitfalls in the manufacture and subsequent performance of a-Si modules are discussed.

New BCJ representations for one-loop amplitudes in gauge theories and gravity

NASA Astrophysics Data System (ADS)

He, Song; Schlotterer, Oliver; Zhang, Yong

2018-05-01

We explain a procedure to manifest the Bern-Carrasco-Johansson duality between color and kinematics in n-point one-loop amplitudes of a variety of supersymmetric gauge theories. Explicit amplitude representations are constructed through a systematic reorganization of the integrands in the Cachazo-He-Yuan formalism. Our construction holds for any nonzero number of supersymmetries and does not depend on the number of spacetime dimensions. The cancellations from supersymmetry multiplets in the loop as well as the resulting power counting of loop momenta is manifested along the lines of the corresponding superstring computations. The setup is used to derive the one-loop version of the Kawai-Lewellen-Tye formula for the loop integrands of gravitational amplitudes.