Meaning of the nuclear wave function
NASA Astrophysics Data System (ADS)
Terry, John D.; Miller, Gerald A.
2016-07-01
Background: The intense current experimental interest in studying the structure of the deuteron and using it to enable accurate studies of neutron structure motivate us to examine the four-dimensional space-time nature of the nuclear wave function and the various approximations used to reduce it to an object that depends only on three spatial variables. Purpose: The aim is to determine if the ability to understand and analyze measured experimental cross sections is compromised by making the reduction from four to three dimensions. Method: Simple, exactly calculable, covariant models of a bound-state wave-state wave function (a scalar boson made of two constituent-scalar bosons) with parameters chosen to represent a deuteron are used to investigate the accuracy of using different approximations to the nuclear wave function to compute the quasielastic scattering cross section. Four different versions of the wave function are defined (light-front-spectator, light-front, light-front with scaling, and nonrelativistic) and used to compute the cross sections as a function of how far off the mass shell (how virtual) is the struck constituent. Results: We show that making an exact calculation of the quasielastic scattering cross section involves using the light-front-spectator wave function. All of the other approaches fail to reproduce the model exact calculation if the value of Bjorken x differs from unity. The model is extended to consider an essential effect of spin to show that constituent nucleons cannot be treated as being on their mass shell even when taking the matrix element of a "good" current. Conclusions: Developing realistic light-front-spectator wave functions to meet the needs of current and planned experiments is a worthwhile activity.
Factorized molecular wave functions: Analysis of the nuclear factor
Lefebvre, R.
2015-06-07
The exact factorization of molecular wave functions leads to nuclear factors which should be nodeless functions. We reconsider the case of vibrational perturbations in a diatomic species, a situation usually treated by combining Born-Oppenheimer products. It was shown [R. Lefebvre, J. Chem. Phys. 142, 074106 (2015)] that it is possible to derive, from the solutions of coupled equations, the form of the factorized function. By increasing artificially the interstate coupling in the usual approach, the adiabatic regime can be reached, whereby the wave function can be reduced to a single product. The nuclear factor of this product is determined by the lowest of the two potentials obtained by diagonalization of the potential matrix. By comparison with the nuclear wave function of the factorized scheme, it is shown that by a simple rectification, an agreement is obtained between the modified nodeless function and that of the adiabatic scheme.
Spin-orbit decomposition of ab initio nuclear wave functions
NASA Astrophysics Data System (ADS)
Johnson, Calvin W.
2015-03-01
Although the modern shell-model picture of atomic nuclei is built from single-particle orbits with good total angular momentum j , leading to j -j coupling, decades ago phenomenological models suggested that a simpler picture for 0 p -shell nuclides can be realized via coupling of the total spin S and total orbital angular momentum L . I revisit this idea with large-basis, no-core shell-model calculations using modern ab initio two-body interactions and dissect the resulting wave functions into their component L - and S -components. Remarkably, there is broad agreement with calculations using the phenomenological Cohen-Kurath forces, despite a gap of nearly 50 years and six orders of magnitude in basis dimensions. I suggest that L -S decomposition may be a useful tool for analyzing ab initio wave functions of light nuclei, for example, in the case of rotational bands.
The adiabatic limit of the exact factorization of the electron-nuclear wave function
NASA Astrophysics Data System (ADS)
Eich, F. G.; Agostini, Federica
2016-08-01
We propose a procedure to analyze the relation between the exact factorization of the electron-nuclear wave function and the Born-Oppenheimer approximation. We define the adiabatic limit as the limit of infinite nuclear mass. To this end, we introduce a unit system that singles out the dependence on the electron-nuclear mass ratio of each term appearing in the equations of the exact factorization. We observe how non-adiabatic effects induced by the coupling to the nuclear motion affect electronic properties and we analyze the leading term, connecting it to the classical nuclear momentum. Its dependence on the mass ratio is tested numerically on a model of proton-coupled electron transfer in different non-adiabatic regimes.
The adiabatic limit of the exact factorization of the electron-nuclear wave function.
Eich, F G; Agostini, Federica
2016-08-01
We propose a procedure to analyze the relation between the exact factorization of the electron-nuclear wave function and the Born-Oppenheimer approximation. We define the adiabatic limit as the limit of infinite nuclear mass. To this end, we introduce a unit system that singles out the dependence on the electron-nuclear mass ratio of each term appearing in the equations of the exact factorization. We observe how non-adiabatic effects induced by the coupling to the nuclear motion affect electronic properties and we analyze the leading term, connecting it to the classical nuclear momentum. Its dependence on the mass ratio is tested numerically on a model of proton-coupled electron transfer in different non-adiabatic regimes. PMID:27497542
Short range structure of hadron and nuclear wave functions at high x
Hoyer, P.; Brodsky, S.J.
1990-11-01
We discuss the short-range structure of hadronic and nuclear wave functions expected in QCD. In addition to the extrinsic'' contributions associated with radiation from single partons, there is an intrinsic'' hardness of the high-mass fluctuations of the wave function due to the spatial overlap of two or more partons. We argue that intrinsically-hard partons, having large mass and/or large transverse momentum, will dominate in the region of large Feynman x{sub F}. Their rescattering in nuclear targets is expected to be larger than for extrinsically-hard partons, leading to a suppressed production cross section for hadrons scattering on heavy nuclei. Experimental evidence for this exists for open chars. J/{psi}, and {gamma} production at large x{sub F}. The effects of intrinsic hardness may be particularly striking in nuclear wave functions, where the overlap of partons belonging to different nucleons can give rise to cumulative (x > 1) phenomena. The data on backward cumulative particle production from nuclei supports the existence of an intrinsically-hard component in nuclear wave functions. Partons at large x{sub F} may also be associated with the enhanced subthreshold production of particles observed in hadron-nucleus and nucleus-nucleus collisions. We discuss the evidence for anomalies in the large angle pp {yields} pp cross section near the charm threshold. Arguments are presented that chromium states may bind to nuclei through the QCD Van der Waals force. This would lead to a striking signal in charm production near threshold. 49 refs., 7 figs.
Scherrer, Arne; Agostini, Federica; Gross, E. K. U.; Sebastiani, Daniel; Vuilleumier, Rodolphe
2015-08-21
The nuclear velocity perturbation theory (NVPT) for vibrational circular dichroism (VCD) is derived from the exact factorization of the electron-nuclear wave function. This new formalism offers an exact starting point to include correction terms to the Born-Oppenheimer (BO) form of the molecular wave function, similar to the complete-adiabatic approximation. The corrections depend on a small parameter that, in a classical treatment of the nuclei, is identified as the nuclear velocity. Apart from proposing a rigorous basis for the NVPT, we show that the rotational strengths, related to the intensity of the VCD signal, contain a new contribution beyond-BO that can be evaluated with the NVPT and that only arises when the exact factorization approach is employed. Numerical results are presented for chiral and non-chiral systems to test the validity of the approach.
NASA Astrophysics Data System (ADS)
Scherrer, Arne; Agostini, Federica; Sebastiani, Daniel; Gross, E. K. U.; Vuilleumier, Rodolphe
2015-08-01
The nuclear velocity perturbation theory (NVPT) for vibrational circular dichroism (VCD) is derived from the exact factorization of the electron-nuclear wave function. This new formalism offers an exact starting point to include correction terms to the Born-Oppenheimer (BO) form of the molecular wave function, similar to the complete-adiabatic approximation. The corrections depend on a small parameter that, in a classical treatment of the nuclei, is identified as the nuclear velocity. Apart from proposing a rigorous basis for the NVPT, we show that the rotational strengths, related to the intensity of the VCD signal, contain a new contribution beyond-BO that can be evaluated with the NVPT and that only arises when the exact factorization approach is employed. Numerical results are presented for chiral and non-chiral systems to test the validity of the approach.
NASA Astrophysics Data System (ADS)
Kolmann, Stephen J.; Jordan, Meredith J. T.
2010-02-01
One of the largest remaining errors in thermochemical calculations is the determination of the zero-point energy (ZPE). The fully coupled, anharmonic ZPE and ground state nuclear wave function of the SSSH radical are calculated using quantum diffusion Monte Carlo on interpolated potential energy surfaces (PESs) constructed using a variety of method and basis set combinations. The ZPE of SSSH, which is approximately 29 kJ mol-1 at the CCSD(T)/6-31G∗ level of theory, has a 4 kJ mol-1 dependence on the treatment of electron correlation. The anharmonic ZPEs are consistently 0.3 kJ mol-1 lower in energy than the harmonic ZPEs calculated at the Hartree-Fock and MP2 levels of theory, and 0.7 kJ mol-1 lower in energy at the CCSD(T)/6-31G∗ level of theory. Ideally, for sub-kJ mol-1 thermochemical accuracy, ZPEs should be calculated using correlated methods with as big a basis set as practicable. The ground state nuclear wave function of SSSH also has significant method and basis set dependence. The analysis of the nuclear wave function indicates that SSSH is localized to a single symmetry equivalent global minimum, despite having sufficient ZPE to be delocalized over both minima. As part of this work, modifications to the interpolated PES construction scheme of Collins and co-workers are presented.
Kolmann, Stephen J; Jordan, Meredith J T
2010-02-01
One of the largest remaining errors in thermochemical calculations is the determination of the zero-point energy (ZPE). The fully coupled, anharmonic ZPE and ground state nuclear wave function of the SSSH radical are calculated using quantum diffusion Monte Carlo on interpolated potential energy surfaces (PESs) constructed using a variety of method and basis set combinations. The ZPE of SSSH, which is approximately 29 kJ mol(-1) at the CCSD(T)/6-31G* level of theory, has a 4 kJ mol(-1) dependence on the treatment of electron correlation. The anharmonic ZPEs are consistently 0.3 kJ mol(-1) lower in energy than the harmonic ZPEs calculated at the Hartree-Fock and MP2 levels of theory, and 0.7 kJ mol(-1) lower in energy at the CCSD(T)/6-31G* level of theory. Ideally, for sub-kJ mol(-1) thermochemical accuracy, ZPEs should be calculated using correlated methods with as big a basis set as practicable. The ground state nuclear wave function of SSSH also has significant method and basis set dependence. The analysis of the nuclear wave function indicates that SSSH is localized to a single symmetry equivalent global minimum, despite having sufficient ZPE to be delocalized over both minima. As part of this work, modifications to the interpolated PES construction scheme of Collins and co-workers are presented. PMID:20136303
NASA Astrophysics Data System (ADS)
Mentink-Vigier, Frédéric; Binet, Laurent; Vignoles, Gerard; Gourier, Didier; Vezin, Hervé
2010-11-01
The hyperfine interactions of the unpaired electron with eight surrounding G69a and G71a nuclei in Ti-doped β-Ga2O3 were analyzed by electron paramagnetic resonance (EPR) and electron-nuclear double resonance (ENDOR) spectroscopies. They are dominated by strong isotropic hyperfine couplings due to a direct Fermi contact interaction with Ga nuclei in octahedral sites of rutile-type chains oriented along b axis, revealing a large anisotropic spatial extension of the electron wave function. Titanium in β-Ga2O3 is thus best described as a diffuse (Ti4+-e-) pair rather than as a localized Ti3+ . Both electron and G69a nuclear spin Rabi oscillations could be observed by pulsed EPR and pulsed ENDOR, respectively. The electron spin decoherence time is about 1μs (at 4 K) and an upper bound of 520μs (at 8 K) is estimated for the nuclear decoherence time. Thus, β-Ga2O3:Ti appears to be a potential spin-bus system for quantum information processing with a large nuclear spin quantum register.
Wave-function frozen-density embedding: Approximate analytical nuclear ground-state gradients.
Heuser, Johannes; Höfener, Sebastian
2016-05-01
We report the derivation of approximate analytical nuclear ground-state uncoupled frozen density embedding (FDEu) gradients for the resolution of identity (RI) variant of the second-order approximate coupled cluster singles and doubles (RICC2) as well as density functional theory (DFT), and an efficient implementation thereof in the KOALA program. In order to guarantee a computationally efficient treatment, those gradient terms are neglected which would require the exchange of orbital information. This approach allows for geometry optimizations of single molecules surrounded by numerous molecules with fixed nuclei at RICC2-in-RICC2, RICC2-in-DFT, and DFT-in-DFT FDE level of theory using a dispersion correction, required due to the DFT-based treatment of the interaction in FDE theory. Accuracy and applicability are assessed by the example of two case studies: (a) the Watson-Crick pair adenine-thymine, for which the optimized structures exhibit a maximum error of about 0.08 Å for our best scheme compared to supermolecular reference calculations, (b) carbon monoxide on a magnesium oxide surface model, for which the error amount up to 0.1 Å for our best scheme. Efficiency is demonstrated by successively including environment molecules and comparing to an optimized conventional supermolecular implementation, showing that the method is able to outperform conventional RICC2 schemes already with a rather small number of environment molecules, gaining significant speed up in computation time. PMID:26804310
Adaptive multiconfigurational wave functions
Evangelista, Francesco A.
2014-03-28
A method is suggested to build simple multiconfigurational wave functions specified uniquely by an energy cutoff Λ. These are constructed from a model space containing determinants with energy relative to that of the most stable determinant no greater than Λ. The resulting Λ-CI wave function is adaptive, being able to represent both single-reference and multireference electronic states. We also consider a more compact wave function parameterization (Λ+SD-CI), which is based on a small Λ-CI reference and adds a selection of all the singly and doubly excited determinants generated from it. We report two heuristic algorithms to build Λ-CI wave functions. The first is based on an approximate prescreening of the full configuration interaction space, while the second performs a breadth-first search coupled with pruning. The Λ-CI and Λ+SD-CI approaches are used to compute the dissociation curve of N{sub 2} and the potential energy curves for the first three singlet states of C{sub 2}. Special attention is paid to the issue of energy discontinuities caused by changes in the size of the Λ-CI wave function along the potential energy curve. This problem is shown to be solvable by smoothing the matrix elements of the Hamiltonian. Our last example, involving the Cu{sub 2}O{sub 2}{sup 2+} core, illustrates an alternative use of the Λ-CI method: as a tool to both estimate the multireference character of a wave function and to create a compact model space to be used in subsequent high-level multireference coupled cluster computations.
Kowalewski, Markus Mukamel, Shaul
2015-07-28
Femtosecond Stimulated Raman Spectroscopy (FSRS) signals that monitor the excited state conical intersections dynamics of acrolein are simulated. An effective time dependent Hamiltonian for two C—H vibrational marker bands is constructed on the fly using a local mode expansion combined with a semi-classical surface hopping simulation protocol. The signals are obtained by a direct forward and backward propagation of the vibrational wave function on a numerical grid. Earlier work is extended to fully incorporate the anharmonicities and intermode couplings.
NASA Astrophysics Data System (ADS)
Kowalewski, Markus; Mukamel, Shaul
2015-07-01
Femtosecond Stimulated Raman Spectroscopy (FSRS) signals that monitor the excited state conical intersections dynamics of acrolein are simulated. An effective time dependent Hamiltonian for two C—H vibrational marker bands is constructed on the fly using a local mode expansion combined with a semi-classical surface hopping simulation protocol. The signals are obtained by a direct forward and backward propagation of the vibrational wave function on a numerical grid. Earlier work is extended to fully incorporate the anharmonicities and intermode couplings.
Properties of resonance wave functions.
NASA Technical Reports Server (NTRS)
More, R. M.; Gerjuoy, E.
1973-01-01
Construction and study of resonance wave functions corresponding to poles of the Green's function for several illustrative models of theoretical interest. Resonance wave functions obtained from the Siegert and Kapur-Peierls definitions of the resonance energies are compared. The comparison especially clarifies the meaning of the normalization constant of the resonance wave functions. It is shown that the wave functions may be considered renormalized in a sense analogous to that of quantum field theory. However, this renormalization is entirely automatic, and the theory has neither ad hoc procedures nor infinite quantities.
Photoelectron wave function in photoionization: plane wave or Coulomb wave?
Gozem, Samer; Gunina, Anastasia O; Ichino, Takatoshi; Osborn, David L; Stanton, John F; Krylov, Anna I
2015-11-19
The calculation of absolute total cross sections requires accurate wave functions of the photoelectron and of the initial and final states of the system. The essential information contained in the latter two can be condensed into a Dyson orbital. We employ correlated Dyson orbitals and test approximate treatments of the photoelectron wave function, that is, plane and Coulomb waves, by comparing computed and experimental photoionization and photodetachment spectra. We find that in anions, a plane wave treatment of the photoelectron provides a good description of photodetachment spectra. For photoionization of neutral atoms or molecules with one heavy atom, the photoelectron wave function must be treated as a Coulomb wave to account for the interaction of the photoelectron with the +1 charge of the ionized core. For larger molecules, the best agreement with experiment is often achieved by using a Coulomb wave with a partial (effective) charge smaller than unity. This likely derives from the fact that the effective charge at the centroid of the Dyson orbital, which serves as the origin of the spherical wave expansion, is smaller than the total charge of a polyatomic cation. The results suggest that accurate molecular photoionization cross sections can be computed with a modified central potential model that accounts for the nonspherical charge distribution of the core by adjusting the charge in the center of the expansion. PMID:26509428
Evanescent Waves Nuclear Magnetic Resonance
Halidi, El Mohamed; Nativel, Eric; Akel, Mohamad; Kenouche, Samir; Coillot, Christophe; Alibert, Eric; Jabakhanji, Bilal; Schimpf, Remy; Zanca, Michel; Stein, Paul; Goze-Bac, Christophe
2016-01-01
Nuclear Magnetic Resonance spectroscopy and imaging can be classified as inductive techniques working in the near- to far-field regimes. We investigate an alternative capacitive detection with the use of micrometer sized probes positioned at sub wavelength distances of the sample in order to characterize and model evanescent electromagnetic fields originating from NMR phenomenon. We report that in this experimental configuration the available NMR signal is one order of magnitude larger and follows an exponential decay inversely proportional to the size of the emitters. Those investigations open a new road to a better understanding of the evanescent waves component in NMR with the opportunity to perform localized spectroscopy and imaging. PMID:26751800
Chasman, R.R.
1995-08-01
In the past few years, we developed many-body variational wave functions that allow one to treat pairing and particle-hole two-body interactions on an equal footing. The complexity of these wave functions depends on the number of levels included in the valence space, but does not depend on the number of nucleons in the system. By using residual interaction strengths (e.g. the quadrupole interaction strength or pairing interaction strength) as generator coordinates, one gets many different wave functions, each having a different expectation value for the relevant interaction mode. These wave functions are particularly useful when one is dealing with a situation in which the mean-field approximation is inadequate. Because the same basis states are used in the construction of the many-body wave functions, it is possible to calculate overlaps and interaction matrix elements for the many-body wave functions (which are not in general orthogonal) easily. The valence space can contain a large number of single-particle basis states, when there are constants of motion that can be used to break the levels up into groups. We added a cranking term to the many-body Hamiltonian and modified the projection procedure to get states of good signature before variation. In our present implementation, each group is limited to eight pairs of single-particle levels. We are working on ways of increasing the number of levels that can be included in each group. We are also working on including particle-particle residual interaction modes, in addition to pairing, in our Hamiltonian.
Nuclear Parton Distribution Functions
I. Schienbein, J.Y. Yu, C. Keppel, J.G. Morfin, F. Olness, J.F. Owens
2009-06-01
We study nuclear effects of charged current deep inelastic neutrino-iron scattering in the framework of a {chi}{sup 2} analysis of parton distribution functions (PDFs). We extract a set of iron PDFs which are used to compute x{sub Bj}-dependent and Q{sup 2}-dependent nuclear correction factors for iron structure functions which are required in global analyses of free nucleon PDFs. We compare our results with nuclear correction factors from neutrino-nucleus scattering models and correction factors for charged-lepton--iron scattering. We find that, except for very high x{sub Bj}, our correction factors differ in both shape and magnitude from the correction factors of the models and charged-lepton scattering.
Coulomb wave functions in momentum space
Eremenko, V; Upadhyay, N. J.; Thompson, I J; Elster, Charlotte; Nunes, F. M.; Arbanas, Goran; Escher, J.E.; Hlophe, L.
2015-01-01
An algorithm to calculate non-relativistic partial-wave Coulomb functions in momentum space is presented. The arguments are the Sommerfeld parameter eta, the angular momentum l, the asymptotic momentum q and the 'running' momentum p, where both momenta are real. Since the partial-wave Coulomb functions exhibit singular behavior when p -> q, different representations of the Legendre functions of the 2nd kind need to be implemented in computing the functions for the values of p close to the singularity and far away from it. The code for the momentum-space Coulomb wave functions is applicable for values of vertical bar eta vertical barmore » in the range of 10(-1) to 10, and thus is particularly suited for momentum space calculations of nuclear reactions. Program Summary Program title: libcwfn Catalogue identifier: AEUQ_v1_0 Program summary URL: http://cpc.cs.qub.ac.uk/summaries/AEUQ_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 864503 No. of bytes in distributed program, including test data, etc.: 7178021 Distribution format: tar.gz Programming language: Fortran 90, Fortran 77, Python, make (GNU Make dialect), GNU Bash shell interpreter (available as /bin/bash). Computer: Apple Powermac (Intel Xeon), ASUS K53U (AMD E-350 (Dual Core)), DELL Precision T3500 (Intel Xeon), NERSC Carver (Intel Nehalem Quad Core). Operating system: Linux, Windows (using Cygwin). RAM: less than 512 Mbytes Classification: 17.8, 17.13, 17.16. Nature of problem: The calculation of partial wave Coulomb functions with integer land all other arguments real. Solution method: Computing the value of the function using explicit formulae and algorithms. Running time: Less than 10(-3) s. (C) 2014 Elsevier B.V. All rights reserved.« less
Coulomb wave functions in momentum space
Eremenko, V; Upadhyay, N. J.; Thompson, I J; Elster, Charlotte; Nunes, F. M.; Arbanas, Goran; Escher, J.E.; Hlophe, L.
2015-01-01
An algorithm to calculate non-relativistic partial-wave Coulomb functions in momentum space is presented. The arguments are the Sommerfeld parameter eta, the angular momentum l, the asymptotic momentum q and the 'running' momentum p, where both momenta are real. Since the partial-wave Coulomb functions exhibit singular behavior when p -> q, different representations of the Legendre functions of the 2nd kind need to be implemented in computing the functions for the values of p close to the singularity and far away from it. The code for the momentum-space Coulomb wave functions is applicable for values of vertical bar eta vertical bar in the range of 10(-1) to 10, and thus is particularly suited for momentum space calculations of nuclear reactions. Program Summary Program title: libcwfn Catalogue identifier: AEUQ_v1_0 Program summary URL: http://cpc.cs.qub.ac.uk/summaries/AEUQ_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 864503 No. of bytes in distributed program, including test data, etc.: 7178021 Distribution format: tar.gz Programming language: Fortran 90, Fortran 77, Python, make (GNU Make dialect), GNU Bash shell interpreter (available as /bin/bash). Computer: Apple Powermac (Intel Xeon), ASUS K53U (AMD E-350 (Dual Core)), DELL Precision T3500 (Intel Xeon), NERSC Carver (Intel Nehalem Quad Core). Operating system: Linux, Windows (using Cygwin). RAM: less than 512 Mbytes Classification: 17.8, 17.13, 17.16. Nature of problem: The calculation of partial wave Coulomb functions with integer land all other arguments real. Solution method: Computing the value of the function using explicit formulae and algorithms. Running time: Less than 10(-3) s. (C) 2014 Elsevier B.V. All rights reserved.
Meson wave function from holographic approaches
Vega, Alfredo; Schmidt, Ivan; Branz, Tanja; Gutsche, Thomas; Lyubovitskij, Valery E.
2010-08-04
We discuss the light-front wave function for the valence quark state of mesons using the AdS/CFT correspondence. We consider two kinds of wave functions obtained in different holographic Soft-Wall approaches.
Adiabatic corrections to density functional theory energies and wave functions.
Mohallem, José R; Coura, Thiago de O; Diniz, Leonardo G; de Castro, Gustavo; Assafrão, Denise; Heine, Thomas
2008-09-25
The adiabatic finite-nuclear-mass-correction (FNMC) to the electronic energies and wave functions of atoms and molecules is formulated for density-functional theory and implemented in the deMon code. The approach is tested for a series of local and gradient corrected density functionals, using MP2 results and diagonal-Born-Oppenheimer corrections from the literature for comparison. In the evaluation of absolute energy corrections of nonorganic molecules the LDA PZ81 functional works surprisingly better than the others. For organic molecules the GGA BLYP functional has the best performance. FNMC with GGA functionals, mainly BLYP, show a good performance in the evaluation of relative corrections, except for nonorganic molecules containing H atoms. The PW86 functional stands out with the best evaluation of the barrier of linearity of H2O and the isotopic dipole moment of HDO. In general, DFT functionals display an accuracy superior than the common belief and because the corrections are based on a change of the electronic kinetic energy they are here ranked in a new appropriate way. The approach is applied to obtain the adiabatic correction for full atomization of alcanes C(n)H(2n+2), n = 4-10. The barrier of 1 mHartree is approached for adiabatic corrections, justifying its insertion into DFT. PMID:18537228
Mechanotransduction and nuclear function.
Graham, David M; Burridge, Keith
2016-06-01
Many signaling pathways converge on the nucleus to regulate crucial nuclear events such as transcription, DNA replication and cell cycle progression. Although the vast majority of research in this area has focused on signals generated in response to hormones or other soluble factors, the nucleus also responds to mechanical forces. During the past decade or so, much has been learned about how mechanical force can affect transcription, as well as the growth and differentiation of cells. Much has also been learned about how force is transmitted via the cytoskeleton to the nucleus and then across the nuclear envelope to the nuclear lamina and chromatin. In this brief review, we focus on some of the key proteins that transmit mechanical signals across the nuclear envelope. PMID:27018929
Meson wave function from holographic models
Vega, Alfredo; Schmidt, Ivan; Branz, Tanja; Gutsche, Thomas; Lyubovitskij, Valery E.
2009-09-01
We consider the light-front wave function for the valence quark state of mesons using the AdS/CFT correspondence, as has been suggested by Brodsky and Teramond. Two kinds of wave functions, obtained in different holographic Soft-Wall models, are discussed.
Chiral density wave in nuclear matter
NASA Astrophysics Data System (ADS)
Heinz, Achim; Giacosa, Francesco; Rischke, Dirk H.
2015-01-01
Inspired by recent work on inhomogeneous chiral condensation in cold, dense quark matter within models featuring quark degrees of freedom, we investigate the chiral density-wave solution in nuclear matter at zero temperature and nonvanishing baryon number density in the framework of the so-called extended linear sigma model (eLSM). The eLSM is an effective model for the strong interaction based on the global chiral symmetry of quantum chromodynamics (QCD). It contains scalar, pseudoscalar, vector, and axial-vector mesons as well as baryons. In the latter sector, the nucleon and its chiral partner are introduced as parity doublets in the mirror assignment. The eLSM simultaneously provides a good description of hadrons in vacuum as well as nuclear matter ground-state properties. We find that an inhomogeneous phase in the form of a chiral density wave is realized, but only for densities larger than 2.4ρ0, where ρ0 is the nuclear matter ground-state density.
Eskola, K.J.; Vogt, R.; Wang, X.N.
1995-07-01
A three parameter Wood-Saxon shape is used to describe the nuclear density distribution, which R{sub A} is the nuclear radius, {approx} is the surface thickness, and {omega} allows for central irregularities. The electron scattering data is used where available for R{sub A}, z, and {omega}. When data is unavailable, the parameters {omega} = O, z = 0.54 fm and R{sub A} = 1.19 A{sup 1/3} - 1.61 A{sup -1/3} fm are used. The central density {rho}{sub 0} is found from the normalization {infinity} d{sup 3}r{rho}{sub A}(r) = A.
Reality and measurement of the wave function
NASA Astrophysics Data System (ADS)
Unruh, W. G.
1994-07-01
Using a simple version of the model for the quantum measurement of a two-level system, the contention of Aharonov, Anandan, and Vaidman [Phys. Rev. A 47, 4616 (1993)] that one must in certain circumstances give the wave function an ontological as well as an epistemological significance is examined. I decide that their argument that the wave function of a system can be measured on a single system fails to establish the key point and that what they demonstrate is the ontological significance of certain operators in the theory, with the wave function playing its usual epistemological role.
Spatial wave functions of photon and electron
Khokhlov, D. L.
2010-12-01
The quantum mechanical model of the photon and electron is considered. The photon is conceived of as a particle moving with the speed of light which is accompanied by the wave function of the photon spreading out with an infinite speed. The wave function of the electron is introduced in terms of virtual photons tied to the electron. A description of electrostatic and magnetostatic interactions is given through the wave functions of electrons. The approach provides an explanation of the results of recent experiments measuring the speed of propagation of the bound magnetic field.
New approach to folding with the Coulomb wave function
Blokhintsev, L. D.; Savin, D. A.; Kadyrov, A. S.; Mukhamedzhanov, A. M.
2015-05-15
Due to the long-range character of the Coulomb interaction theoretical description of low-energy nuclear reactions with charged particles still remains a formidable task. One way of dealing with the problem in an integral-equation approach is to employ a screened Coulomb potential. A general approach without screening requires folding of kernels of the integral equations with the Coulomb wave. A new method of folding a function with the Coulomb partial waves is presented. The partial-wave Coulomb function both in the configuration and momentum representations is written in the form of separable series. Each term of the series is represented as a product of a factor depending only on the Coulomb parameter and a function depending on the spatial variable in the configuration space and the momentum variable if the momentum representation is used. Using a trial function, the method is demonstrated to be efficient and reliable.
Explicitly correlated wave function for a boron atom
NASA Astrophysics Data System (ADS)
Puchalski, Mariusz; Komasa, Jacek; Pachucki, Krzysztof
2015-12-01
We present results of high-precision calculations for a boron atom's properties using wave functions expanded in the explicitly correlated Gaussian basis. We demonstrate that the well-optimized 8192 basis functions enable a determination of energy levels, ionization potential, and fine and hyperfine splittings in atomic transitions with nearly parts per million precision. The results open a window to a spectroscopic determination of nuclear properties of boron including the charge radius of the proton halo in the 8B nucleus.
The geometry of electron wave functions
Aminov, Yurii A
2013-02-28
To each wave function we assign a codimension-two submanifold in Euclidean space. We study the case of the wave function of a single electron in the hydrogen atom or other hydrogen-type atoms with quantum numbers n, l, m in detail. We prove theorems describing the behaviour of the scalar and sectional curvature of the constructed submanifold, depending on the quantum numbers. We also consider the external geometry of the submanifold. Bibliography: 9 titles.
Weak measurement and Bohmian conditional wave functions
Norsen, Travis; Struyve, Ward
2014-11-15
It was recently pointed out and demonstrated experimentally by Lundeen et al. that the wave function of a particle (more precisely, the wave function possessed by each member of an ensemble of identically-prepared particles) can be “directly measured” using weak measurement. Here it is shown that if this same technique is applied, with appropriate post-selection, to one particle from a perhaps entangled multi-particle system, the result is precisely the so-called “conditional wave function” of Bohmian mechanics. Thus, a plausibly operationalist method for defining the wave function of a quantum mechanical sub-system corresponds to the natural definition of a sub-system wave function which Bohmian mechanics uniquely makes possible. Similarly, a weak-measurement-based procedure for directly measuring a sub-system’s density matrix should yield, under appropriate circumstances, the Bohmian “conditional density matrix” as opposed to the standard reduced density matrix. Experimental arrangements to demonstrate this behavior–and also thereby reveal the non-local dependence of sub-system state functions on distant interventions–are suggested and discussed. - Highlights: • We study a “direct measurement” protocol for wave functions and density matrices. • Weakly measured states of entangled particles correspond to Bohmian conditional states. • Novel method of observing quantum non-locality is proposed.
Functional evolution of nuclear structure
Dawson, Scott C.
2011-01-01
The evolution of the nucleus, the defining feature of eukaryotic cells, was long shrouded in speculation and mystery. There is now strong evidence that nuclear pore complexes (NPCs) and nuclear membranes coevolved with the endomembrane system, and that the last eukaryotic common ancestor (LECA) had fully functional NPCs. Recent studies have identified many components of the nuclear envelope in living Opisthokonts, the eukaryotic supergroup that includes fungi and metazoan animals. These components include diverse chromatin-binding membrane proteins, and membrane proteins with adhesive lumenal domains that may have contributed to the evolution of nuclear membrane architecture. Further discoveries about the nucleoskeleton suggest that the evolution of nuclear structure was tightly coupled to genome partitioning during mitosis. PMID:22006947
The Wave Function and Quantum Reality
Gao Shan
2011-03-28
We investigate the meaning of the wave function by analyzing the mass and charge density distributions of a quantum system. According to protective measurement, a charged quantum system has effective mass and charge density distributing in space, proportional to the square of the absolute value of its wave function. In a realistic interpretation, the wave function of a quantum system can be taken as a description of either a physical field or the ergodic motion of a particle. The essential difference between a field and the ergodic motion of a particle lies in the property of simultaneity; a field exists throughout space simultaneously, whereas the ergodic motion of a particle exists throughout space in a time-divided way. If the wave function is a physical field, then the mass and charge density will be distributed in space simultaneously for a charged quantum system, and thus there will exist gravitational and electrostatic self-interactions of its wave function. This not only violates the superposition principle of quantum mechanics but also contradicts experimental observations. Thus the wave function cannot be a description of a physical field but be a description of the ergodic motion of a particle. For the later there is only a localized particle with mass and charge at every instant, and thus there will not exist any self-interaction for the wave function. It is further argued that the classical ergodic models, which assume continuous motion of particles, cannot be consistent with quantum mechanics. Based on the negative result, we suggest that the wave function is a description of the quantum motion of particles, which is random and discontinuous in nature. On this interpretation, the square of the absolute value of the wave function not only gives the probability of the particle being found in certain locations, but also gives the probability of the particle being there. The suggested new interpretation of the wave function provides a natural realistic
The evolution of oscillator wave functions
NASA Astrophysics Data System (ADS)
Andrews, Mark
2016-04-01
We investigate how wave functions evolve with time in the harmonic oscillator. We first review the periodicity properties over each multiple of a quarter of the classical oscillation period. Then we show that any wave function can be simply transformed so that its centroid, defined by the expectation values of position and momentum, remains at rest at the center of the oscillator. This implies that we need only consider the evolution of this restricted class of wave functions; the evolution of all others can be reduced to these. The evolution of the spread in position Δx and momentum Δp throws light on energy and uncertainty and on squeezed and coherent states. Finally, we show that any wave function can be transformed so that Δx and Δp do not change with time and that the evolution of all wave functions can easily be found from the evolution of those at rest at the origin with unchanging Δx and Δp.
Plasmon wave function of graphene nanoribbons
NASA Astrophysics Data System (ADS)
Silveiro, I.; Plaza Ortega, J. M.; García de Abajo, F. J.
2015-08-01
We find the low-frequency optical response of highly doped individual and arrayed graphene nanoribbons to be accurately described in terms of plasmon wave functions (PWFs). More precisely, we focus on the lowest-order transverse dipolar mode, for which we define the wave function as the induced charge density associated with the plasmon. We show that a single universal wave function is capable of describing the normal-incidence interaction of paired, co-planar, and stacked arrays of ribbons down to small inter-ribbon distances. Our work provides both intuitive insight into graphene plasmon interactions and a practical way of accurately describing complex graphene geometries based on the PWFs of the individual components.
Spontaneous symmetry breaking in correlated wave functions
NASA Astrophysics Data System (ADS)
Kaneko, Ryui; Tocchio, Luca F.; Valentí, Roser; Becca, Federico; Gros, Claudius
2016-03-01
We show that Jastrow-Slater wave functions, in which a density-density Jastrow factor is applied onto an uncorrelated fermionic state, may possess long-range order even when all symmetries are preserved in the wave function. This fact is mainly related to the presence of a sufficiently strong Jastrow term (also including the case of full Gutzwiller projection, suitable for describing spin models). Selected examples are reported, including the spawning of Néel order and dimerization in spin systems, and the stabilization of charge and orbital order in itinerant electronic systems.
Nonlinear wave function expansions : a progress report.
Shepard, R.; Minkoff, M.; Brozell, S. R.; Chemistry
2007-12-01
Some recent progress is reported for a novel nonlinear expansion form for electronic wave functions. This expansion form is based on spin eigenfunctions using the Graphical Unitary Group Approach and the wave function is expanded in a basis of product functions, allowing application to closed and open shell systems and to ground and excited electronic states. Each product basis function is itself a multiconfigurational expansion that depends on a relatively small number of nonlinear parameters called arc factors. Efficient recursive procedures for the computation of reduced one- and two-particle density matrices, overlap matrix elements, and Hamiltonian matrix elements result in a very efficient computational procedure that is applicable to very large configuration state function (CSF) expansions. A new energy-based optimization approach is presented based on product function splitting and variational recombination. Convergence of both valence correlation energy and dynamical correlation energy with respect to the product function basis dimension is examined. A wave function analysis approach suitable for very large CSF expansions is presented based on Shavitt graph node density and arc density. Some new closed-form expressions for various Shavitt Graph and Auxiliary Pair Graph statistics are presented.
Multifractal wave functions of simple quantum maps
NASA Astrophysics Data System (ADS)
Martin, John; García-Mata, Ignacio; Giraud, Olivier; Georgeot, Bertrand
2010-10-01
We study numerically multifractal properties of two models of one-dimensional quantum maps: a map with pseudointegrable dynamics and intermediate spectral statistics and a map with an Anderson-like transition recently implemented with cold atoms. Using extensive numerical simulations, we compute the multifractal exponents of quantum wave functions and study their properties, with the help of two different numerical methods used for classical multifractal systems (box-counting and wavelet methods). We compare the results of the two methods over a wide range of values. We show that the wave functions of the Anderson map display a multifractal behavior similar to eigenfunctions of the three-dimensional Anderson transition but of a weaker type. Wave functions of the intermediate map share some common properties with eigenfunctions at the Anderson transition (two sets of multifractal exponents, with similar asymptotic behavior), but other properties are markedly different (large linear regime for multifractal exponents even for strong multifractality, different distributions of moments of wave functions, and absence of symmetry of the exponents). Our results thus indicate that the intermediate map presents original properties, different from certain characteristics of the Anderson transition derived from the nonlinear sigma model. We also discuss the importance of finite-size effects.
Constructibility of the Universal Wave Function
NASA Astrophysics Data System (ADS)
Bolotin, Arkady
2016-05-01
This paper focuses on a constructive treatment of the mathematical formalism of quantum theory and a possible role of constructivist philosophy in resolving the foundational problems of quantum mechanics, particularly, the controversy over the meaning of the wave function of the universe. As it is demonstrated in the paper, unless the number of the universe's degrees of freedom is fundamentally upper bounded (owing to some unknown physical laws) or hypercomputation is physically realizable, the universal wave function is a non-constructive entity in the sense of constructive recursive mathematics. This means that even if such a function might exist, basic mathematical operations on it would be undefinable and subsequently the only content one would be able to deduce from this function would be pure symbolical.
Millimeter wave detection of nuclear radiation - an alternative detection mechanism.
Gopalsami, N.; Chien, H. T.; Heifetz, A.; Koehl, E. R.; Raptis, A. C.; Nuclear Engineering Division
2009-08-01
We present a nuclear radiation detection mechanism using millimeter waves as an alternative to conventional detection. It is based on the concept that nuclear radiation causes ionization of air and that if we place a dielectric material near the radiation source, it acts as a charge accumulator of the air ions. We have found that millimeter waves can interrogate the charge cloud on the dielectric material remotely. This concept was tested with a standoff millimeter wave system by monitoring the charge levels on a cardboard tube placed in an x-ray beam.
Millimeter wave detection of nuclear radiation: An alternative detection mechanism
Gopalsami, N.; Chien, H. T.; Heifetz, A.; Koehl, E. R.; Raptis, A. C.
2009-08-15
We present a nuclear radiation detection mechanism using millimeter waves as an alternative to conventional detection. It is based on the concept that nuclear radiation causes ionization of air and that if we place a dielectric material near the radiation source, it acts as a charge accumulator of the air ions. We have found that millimeter waves can interrogate the charge cloud on the dielectric material remotely. This concept was tested with a standoff millimeter wave system by monitoring the charge levels on a cardboard tube placed in an x-ray beam.
Millimeter wave detection of nuclear radiation: An alternative detection mechanism
NASA Astrophysics Data System (ADS)
Gopalsami, N.; Chien, H. T.; Heifetz, A.; Koehl, E. R.; Raptis, A. C.
2009-08-01
We present a nuclear radiation detection mechanism using millimeter waves as an alternative to conventional detection. It is based on the concept that nuclear radiation causes ionization of air and that if we place a dielectric material near the radiation source, it acts as a charge accumulator of the air ions. We have found that millimeter waves can interrogate the charge cloud on the dielectric material remotely. This concept was tested with a standoff millimeter wave system by monitoring the charge levels on a cardboard tube placed in an x-ray beam.
Millimeter wave detection of nuclear radiation: an alternative detection mechanism.
Gopalsami, N; Chien, H T; Heifetz, A; Koehl, E R; Raptis, A C
2009-08-01
We present a nuclear radiation detection mechanism using millimeter waves as an alternative to conventional detection. It is based on the concept that nuclear radiation causes ionization of air and that if we place a dielectric material near the radiation source, it acts as a charge accumulator of the air ions. We have found that millimeter waves can interrogate the charge cloud on the dielectric material remotely. This concept was tested with a standoff millimeter wave system by monitoring the charge levels on a cardboard tube placed in an x-ray beam. PMID:19725673
General Forms of Wave Functions for Dipositronium, Ps2
NASA Technical Reports Server (NTRS)
Schrader, D.M.
2007-01-01
The consequences of particle interchange symmetry for the structure of wave functions of the states of dipositronium was recently discussed by the author [I]. In the present work, the methodology is simply explained, and the wave functions are explicitly given.
NASA Astrophysics Data System (ADS)
Douglas, A.; Marshall, P. D.; Young, J. B.
1993-06-01
The t* (the ratio of the travel time to the specific quality factor) estimates of Chun et al. (1991) for P waves for paths from several test sites to the Yellowknife array (YKA) are argued to be strongly dependent on the assumptions made about the source; there is little evidence that the source models of explosions derived from close-in observations yield reliable predictions of the source pulse radiated to long range. With frequency domain methods the confidence limits on the rate of falloff of source-corrected explosion spectra may be low and give the impression that the t* estimates are well constrained. However, because of the uncertainties in the source spectra the confidence limits must be underestimates of the true values. In their reply Chun et al. argue that that their t* estimates are higher than the published single-window values. A proper determination of the frequency dependence of t* requires, among other things, elucidation of the role of scattering attenuation.
Covariance Constraints for Light Front Wave Functions
NASA Astrophysics Data System (ADS)
Müller, D.
2016-06-01
Light front wave functions (LFWFs) are often utilized to model parton distributions and form factors where their transverse and longitudinal momenta are tied to each other in some manner that is often guided by convenience. On the other hand, the cross talk of transverse and longitudinal momenta is governed by Poincaré symmetry and thus popular LFWF models are often not usable to model more intricate quantities such as generalized parton distributions. In this contribution a closer look to this issue is given and it is shown how to overcome the issue for two-body LFWFs.
Lanczos steps to improve variational wave functions
NASA Astrophysics Data System (ADS)
Becca, Federico; Hu, Wen-Jun; Iqbal, Yasir; Parola, Alberto; Poilblanc, Didier; Sorella, Sandro
2015-09-01
Gutzwiller-projected fermionic states can be efficiently implemented within quantum Monte Carlo calculations to define extremely accurate variational wave functions for Heisenberg models on frustrated two-dimensional lattices, not only for the ground state but also for low-energy excitations. The application of few Lanczos steps on top of these states further improves their accuracy, allowing calculations on large clusters. In addition, by computing both the energy and its variance, it is possible to obtain reliable estimations of exact results. Here, we report the cases of the frustrated Heisenberg models on square and Kagome lattices.
Variational wave functions for homogenous Bose systems
Sueto, Andras; Szepfalusy, Peter
2008-02-15
We study variational wave functions of the product form, factorizing according to the wave vectors k, for the ground state of a system of bosons interacting via positive pair interactions with a positive Fourier transform. Our trial functions are members of different orthonormal bases in Fock space. Each basis contains a quasiparticle vacuum state and states with an arbitrary finite number of quasiparticles. One of the bases is that of Valatin and Butler (VB), introduced fifty years ago and parametrized by an infinite set of variables determining Bogoliubov's canonical transformation for each k. In another case, inspired by Nozieres and Saint James the canonical transformation for k=0 is replaced by a shift in the creation/annihilation operators. For the VB basis we prove that the lowest energy is obtained in a state with {approx}{radical}(volume) quasiparticles in the zero mode. The number of k=0 physical particles is of the order of the volume and its fluctuation is anomalously large, resulting in an excess energy. The same fluctuation is normal in the second type of optimized bases, the minimum energy is smaller and is attained in a vacuum state. Associated quasiparticle theories and questions about the gap in their spectrum are also discussed.
String wave function across a Kasner singularity
Copeland, Edmund J.; Niz, Gustavo; Turok, Neil
2010-06-15
A collision of orbifold planes in 11 dimensions has been proposed as an explanation of the hot big bang. When the two planes are close to each other, the winding membranes become the lightest modes of the theory, and can be effectively described in terms of fundamental strings in a ten-dimensional background. Near the brane collision, the 11-dimensional metric is a Euclidean space times a 1+1-dimensional Milne universe. However, one may expect small perturbations to lead into a more general Kasner background. In this paper we extend the previous classical analysis of winding membranes to Kasner backgrounds, and using the Hamiltonian equations, solve for the wave function of loops with circular symmetry. The evolution across the singularity is regular, and explained in terms of the excitement of higher oscillation modes. We also show there is finite particle production and unitarity is preserved.
Computer network defense through radial wave functions
NASA Astrophysics Data System (ADS)
Malloy, Ian J.
The purpose of this research is to synthesize basic and fundamental findings in quantum computing, as applied to the attack and defense of conventional computer networks. The concept focuses on uses of radio waves as a shield for, and attack against traditional computers. A logic bomb is analogous to a landmine in a computer network, and if one was to implement it as non-trivial mitigation, it will aid computer network defense. As has been seen in kinetic warfare, the use of landmines has been devastating to geopolitical regions in that they are severely difficult for a civilian to avoid triggering given the unknown position of a landmine. Thus, the importance of understanding a logic bomb is relevant and has corollaries to quantum mechanics as well. The research synthesizes quantum logic phase shifts in certain respects using the Dynamic Data Exchange protocol in software written for this work, as well as a C-NOT gate applied to a virtual quantum circuit environment by implementing a Quantum Fourier Transform. The research focus applies the principles of coherence and entanglement from quantum physics, the concept of expert systems in artificial intelligence, principles of prime number based cryptography with trapdoor functions, and modeling radio wave propagation against an event from unknown parameters. This comes as a program relying on the artificial intelligence concept of an expert system in conjunction with trigger events for a trapdoor function relying on infinite recursion, as well as system mechanics for elliptic curve cryptography along orbital angular momenta. Here trapdoor both denotes the form of cipher, as well as the implied relationship to logic bombs.
Nonlinear Trivelpiece-Gould Waves: Frequency, Functional Form, and Stability
NASA Astrophysics Data System (ADS)
Dubin, Daniel H. E.
2015-11-01
This poster considers the frequency, spatial form, and stability, of nonlinear Trivelpiece- Gould (TG) waves on a cylindrical plasma column of length L and radius rp, treating both traveling and standing waves, and focussing on the regime of experimental interest in which L/rp >> 1. In this regime TG waves are weakly dispersive, allowing strong mode-coupling between Fourier harmonics. The mode coupling implies that linear theory for such waves is a poor approximation even at fairly small amplitudes, and nonlinear theories that include only a small number of harmonics (such as 3-wave parametric resonance theory) fail to fully capture the stability properties of the system. We find that nonlinear standing waves suffer jumps in their functional form as their amplitude is varied continuously. The jumps are caused by nonlinear resonances between the standing wave and nearly linear waves whose frequencies and wave numbers are harmonics of the standing wave. Also, the standing waves are found to be unstable to a multi-wave version of 3-wave parametric resonance, with an amplitude required for instability onset that is much larger than expected from three wave theory. For traveling wave, linearly stability is found for all amplitudes that could be studied, in contradiction to 3-wave theory. Supported by National Science Foundation Grant PHY-1414570, Department of Energy Grants DE-SC0002451and DE-SC0008693.
Holographic Wave Functions, Meromorphization and Counting Rules
Anatoly Radyushkin
2006-05-10
We study the large-Q{sup 2} behavior of the meson form factor F{sub M} (Q{sup 2}) constructed using the holographic light-front wave functions proposed recently by Brodsky and de Teramond. We show that this model can be also obtained within the Migdal's regularization approach (''meromorphization''), if one applies it to 3-point function for scalar currents made of scalar quarks. We found that the asymptotic 1/Q{sup 2} behavior of F{sub M} (Q{sup 2}) is generated by soft Feynman mechanism rather than by short distance dynamics, which causes very late onset of the 1/Q{sup 2} asymptotic behavior. It becomes visible only for unaccessible momenta Q{sup 2} {approx}> 10, GeV{sup 2}. Using meromorphization for spin-1/2 quarks, we demonstrated that resulting form factor F{sup spinor}{sub M} (Q{sup 2}) has 1/Q{sup 4} asymptotic behavior. Now, owing to the late onset of this asymptotic pattern, F{sup spinor}{sub M} (Q{sup 2}) imitates the 1/Q{sup 2} behavior in the few GeV{sup 2} region.
Quasirelativistic quasilocal finite wave-function collapse model
Pearle, Philip
2005-03-01
A Markovian wave-function collapse model is presented where the collapse-inducing operator, constructed from quantum fields, is a manifestly covariant generalization of the mass-density operator utilized in the nonrelativistic continuous spontaneous localization (CSL) wave-function collapse model. However, the model is not Lorentz invariant because two such operators do not commute at spacelike separation, i.e., the time-ordering operation in one Lorentz frame, the 'preferred' frame, is not the time-ordering operation in another frame. However, the characteristic spacelike distance over which the commutator decays is the particle's Compton wavelength so, since the commutator rapidly gets quite small, the model is 'almost' relativistic. This quasirelativistic CSL (QRCSL) model is completely finite: unlike previous, relativistic, models, it has no (infinite) energy production from the vacuum state. QRCSL calculations are given of the collapse rate for a single free particle in a superposition of spatially separated packets, and of the energy production rate for any number of free particles: these reduce to the CSL rates if the particle's Compton wavelength is small compared to the model's distance parameter. One motivation for QRCSL is the realization that previous relativistic models entail excitation of nuclear states which exceeds that of experiment, whereas QRCSL does not; an example is given involving quadrupole excitation of the {sup 74}Ge nucleus.
Plant nuclear proteomics for unraveling physiological function.
Yin, Xiaojian; Komatsu, Setsuko
2016-09-25
The nucleus is the subcellular organelle that functions as the regulatory hub of the cell and is responsible for regulating several critical cellular functions, including cell proliferation, gene expression, and cell survival. Nuclear proteomics is a useful approach for investigating the mechanisms underlying plant responses to abiotic stresses, including protein-protein interactions, enzyme activities, and post-translational modifications. Among abiotic stresses, flooding is a major limiting factor for plant growth and yields, particularly for soybean. In this review, plant nuclei purification methods, modifications of plant nuclear proteins, and recent contributions to the field of plant nuclear proteomics are summarized. In addition, to reveal the upstream regulating mechanisms controlling soybean responses to flooding stress, the functions of flooding-responsive nuclear proteins are reviewed based on the results of nuclear proteomic analysis of soybean in the early stages of flooding stress. PMID:27004615
Bohmian mechanics without wave function ontology
NASA Astrophysics Data System (ADS)
Solé, Albert
2013-11-01
In this paper, I critically assess different interpretations of Bohmian mechanics that are not committed to an ontology based on the wave function being an actual physical object that inhabits configuration space. More specifically, my aim is to explore the connection between the denial of configuration space realism and another interpretive debate that is specific to Bohmian mechanics: the quantum potential versus guidance approaches. Whereas defenders of the quantum potential approach to the theory claim that Bohmian mechanics is better formulated as quasi-Newtonian, via the postulation of forces proportional to acceleration; advocates of the guidance approach defend the notion that the theory is essentially first-order and incorporates some concepts akin to those of Aristotelian physics. Here I analyze whether the desideratum of an interpretation of Bohmian mechanics that is both explanatorily adequate and not committed to configuration space realism favors one of these two approaches to the theory over the other. Contrary to some recent claims in the literature, I argue that the quasi-Newtonian approach based on the idea of a quantum potential does not come out the winner.
Imaging the wave functions of adsorbed molecules
Lüftner, Daniel; Ules, Thomas; Reinisch, Eva Maria; Koller, Georg; Soubatch, Serguei; Tautz, F. Stefan; Ramsey, Michael G.; Puschnig, Peter
2014-01-01
The basis for a quantum-mechanical description of matter is electron wave functions. For atoms and molecules, their spatial distributions and phases are known as orbitals. Although orbitals are very powerful concepts, experimentally only the electron densities and -energy levels are directly observable. Regardless whether orbitals are observed in real space with scanning probe experiments, or in reciprocal space by photoemission, the phase information of the orbital is lost. Here, we show that the experimental momentum maps of angle-resolved photoemission from molecular orbitals can be transformed to real-space orbitals via an iterative procedure which also retrieves the lost phase information. This is demonstrated with images obtained of a number of orbitals of the molecules pentacene (C22H14) and perylene-3,4,9,10-tetracarboxylic dianhydride (C24H8O6), adsorbed on silver, which are in excellent agreement with ab initio calculations. The procedure requires no a priori knowledge of the orbitals and is shown to be simple and robust. PMID:24344291
Universal Nuclear Energy Density Functional
Carlson, Joseph; Furnstahl, Richard; Horoi, Mihai; Lusk, Rusty; Nazarewicz, Witold; Ng, Esmond; Thompson, Ian; Vary, James
2012-12-01
An understanding of the properties of atomic nuclei is crucial for a complete nuclear theory, for element formation, for properties of stars, and for present and future energy and defense applications. During the period of Dec. 1 2006 – Jun. 30, 2012, the UNEDF collaboration carried out a comprehensive study of all nuclei, based on the most accurate knowledge of the strong nuclear interaction, the most reliable theoretical approaches, the most advanced algorithms, and extensive computational resources, with a view towards scaling to the petaflop platforms and beyond. Until recently such an undertaking was hard to imagine, and even at the present time such an ambitious endeavor would be far beyond what a single researcher or a traditional research group could carry out.
Meson's correlation functions in a nuclear medium
NASA Astrophysics Data System (ADS)
Park, Chanyong
2016-09-01
We investigate meson's spectrum, decay constant and form factor in a nuclear medium through holographic two- and three-point correlation functions. To describe a nuclear medium composed of protons and neutrons, we consider a hard wall model on the thermal charged AdS geometry and show that due to the isospin interaction with a nuclear medium, there exist splittings of the meson's spectrum, decay constant and form factor relying on the isospin charge. In addition, we show that the ρ-meson's form factor describing an interaction with pseudoscalar fluctuation decreases when the nuclear density increases, while the interaction with a longitudinal part of an axial vector meson increases.
Light Front Wave Function for Hadrons with Arbitrary Twist
NASA Astrophysics Data System (ADS)
Vega, Alfredo; Schmidt, Ivan; Gutsche, Thomas; Lyubovitskij, Valery E.
2016-07-01
We present a phenomenological light-front wave function for hadrons with arbitrary twist dimension (mesons, baryons and multiquark states), which gives the correct scaling behavior of structure functions and form factors. Some examples of his uses are presented.
Light Front Wave Function for Hadrons with Arbitrary Twist
NASA Astrophysics Data System (ADS)
Vega, Alfredo; Schmidt, Ivan; Gutsche, Thomas; Lyubovitskij, Valery E.
2016-05-01
We present a phenomenological light-front wave function for hadrons with arbitrary twist dimension (mesons, baryons and multiquark states), which gives the correct scaling behavior of structure functions and form factors. Some examples of his uses are presented.
Wind-wave source functions in opposing seas
NASA Astrophysics Data System (ADS)
Langodan, Sabique; Cavaleri, Luigi; Viswanadhapalli, Yesubabu; Hoteit, Ibrahim
2015-10-01
The Red Sea is a challenge for wave modeling because of its unique two opposed wave systems, forced by opposite winds and converging at its center. We investigate the different physical aspects of wave evolution and propagation in the convergence zone. The two opposing wave systems have similar amplitude and frequency, each driven by the action of its own wind. Wave patterns at the center of the Red Sea, as derived from extensive tests and intercomparison between model and measured data, suggest that the currently available wave model source functions may not properly represent the evolution of the local fields that appear to be characterized by a less effective wind input and an enhanced white-capping. We propose and test a possible simple solution to improve the wave-model simulation under opposing winds and waves condition.
Wave function continuity and the diagonal Born-Oppenheimer correction at conical intersections
NASA Astrophysics Data System (ADS)
Meek, Garrett A.; Levine, Benjamin G.
2016-05-01
We demonstrate that though exact in principle, the expansion of the total molecular wave function as a sum over adiabatic Born-Oppenheimer (BO) vibronic states makes inclusion of the second-derivative nonadiabatic energy term near conical intersections practically problematic. In order to construct a well-behaved molecular wave function that has density at a conical intersection, the individual BO vibronic states in the summation must be discontinuous. When the second-derivative nonadiabatic terms are added to the Hamiltonian, singularities in the diagonal BO corrections (DBOCs) of the individual BO states arise from these discontinuities. In contrast to the well-known singularities in the first-derivative couplings at conical intersections, these singularities are non-integrable, resulting in undefined DBOC matrix elements. Though these singularities suggest that the exact molecular wave function may not have density at the conical intersection point, there is no physical basis for this constraint. Instead, the singularities are artifacts of the chosen basis of discontinuous functions. We also demonstrate that continuity of the total molecular wave function does not require continuity of the individual adiabatic nuclear wave functions. We classify nonadiabatic molecular dynamics methods according to the constraints placed on wave function continuity and analyze their formal properties. Based on our analysis, it is recommended that the DBOC be neglected when employing mixed quantum-classical methods and certain approximate quantum dynamical methods in the adiabatic representation.
Wave function continuity and the diagonal Born-Oppenheimer correction at conical intersections.
Meek, Garrett A; Levine, Benjamin G
2016-05-14
We demonstrate that though exact in principle, the expansion of the total molecular wave function as a sum over adiabatic Born-Oppenheimer (BO) vibronic states makes inclusion of the second-derivative nonadiabatic energy term near conical intersections practically problematic. In order to construct a well-behaved molecular wave function that has density at a conical intersection, the individual BO vibronic states in the summation must be discontinuous. When the second-derivative nonadiabatic terms are added to the Hamiltonian, singularities in the diagonal BO corrections (DBOCs) of the individual BO states arise from these discontinuities. In contrast to the well-known singularities in the first-derivative couplings at conical intersections, these singularities are non-integrable, resulting in undefined DBOC matrix elements. Though these singularities suggest that the exact molecular wave function may not have density at the conical intersection point, there is no physical basis for this constraint. Instead, the singularities are artifacts of the chosen basis of discontinuous functions. We also demonstrate that continuity of the total molecular wave function does not require continuity of the individual adiabatic nuclear wave functions. We classify nonadiabatic molecular dynamics methods according to the constraints placed on wave function continuity and analyze their formal properties. Based on our analysis, it is recommended that the DBOC be neglected when employing mixed quantum-classical methods and certain approximate quantum dynamical methods in the adiabatic representation. PMID:27179473
High-Frequency Gravitational Wave Induced Nuclear Fusion
Fontana, Giorgio; Baker, Robert M. L. Jr.
2007-01-30
Nuclear fusion is a process in which nuclei, having a total initial mass, combine to produce a single nucleus, having a final mass less than the total initial mass. Below a given atomic number the process is exothermic; that is, since the final mass is less than the combined initial mass and the mass deficit is converted into energy by the nuclear fusion. On Earth nuclear fusion does not happen spontaneously because electrostatic barriers prevent the phenomenon. To induce controlled, industrial scale, nuclear fusion, only a few methods have been discovered that look promising, but net positive energy production is not yet possible because of low overall efficiency of the systems. In this paper we propose that an intense burst of High Frequency Gravitational Waves (HFGWs) could be focused or beamed to a target mass composed of appropriate fuel or target material to efficiently rearrange the atomic or nuclear structure of the target material with consequent nuclear fusion. Provided that efficient generation of HFGW can be technically achieved, the proposed fusion reactor could become a viable solution for the energy needs of mankind and alternatively a process for beaming energy to produce a source of fusion energy remotely - even inside solid materials.
Modular matrices from universal wave-function overlaps in Gutzwiller-projected parton wave functions
NASA Astrophysics Data System (ADS)
Mei, Jia-Wei; Wen, Xiao-Gang
2015-03-01
We implement the universal wave-function overlap (UWFO) method to extract modular S and T matrices for topological orders in Gutzwiller-projected parton wave functions (GPWFs). The modular S and T matrices generate a projective representation of S L (2 ,Z ) on the degenerate-ground-state Hilbert space on a torus and may fully characterize the 2+1D topological orders, i.e., the quasiparticle statistics and chiral central charge (up to E8 bosonic quantum Hall states). We use the variational Monte Carlo method to computed the S and T matrices of the chiral spin liquid (CSL) constructed by the GPWF on the square lattice, and we confirm that the CSL carries the same topological order as the ν =1/2 bosonic Laughlin state. We find that the nonuniversal exponents in the UWFO can be small, and direct numerical computation can be applied on relatively large systems. The UWFO may be a powerful method to calculate the topological order in GPWFs.
Joint inversion of body wave receiver function and Rayleigh wave ellipticity
NASA Astrophysics Data System (ADS)
Chong, J.; Ni, S.; Chu, R.
2015-12-01
In recent years, surface wave dispersion has been used to image lithospheric structure jointly with receiver function, or Rayleigh wave ellipticity (Julia et al., 2000; Lin et al., 2012). Because surface wave dispersion is the total propagation effect of the travel path, the joint inversion relies on dense seismic arrays or high seismicity to obtain local velocity structure. However, both receiver function and Rayleigh wave ellipticity are single station measurements with localized sensitivities and could be combined for joint inversion naturally. In this study we explored the feasibility of the joint inversion of Rayleigh wave ellipticity and receiver function. We performed sensitivity tests with forward modeling, and found that the receiver function is sensitive to sharp velocity interfaces but shows weak sensitivity to long wavelength structure, almost complementary to Rayleigh wave ellipticity. Therefore, joint inversion with two single-station measurements provides tighter constraints on the velocity structure beneath the seismic station. A joint inversion algorithm based on the Fast Simulated Annealing method is developed to invert Rayleigh wave ellipticity and receiver function for the lithospheric structure. Application of the algorithm to the Indian Craton and the Williston Basin in the United States demonstrates its effectiveness in reducing the non-uniqueness of the inversion. However, the joint inversion is not sensitive to average crustal velocity, suggesting the need to combine surface wave dispersion, receiver function and Rayleigh wave ellipticity to more accurately resolve the velocity structure. ReferenceJuliá, J., C. Ammon, R. Herrmann, and A. Correig, 2000. Joint inversion of receiver function and surface wave dispersion observations, Geophys. J. Int., 143(1), 99-112. Lin F.C., Schmandt B. and Tsai V.C., 2012. Joint inversion of Rayleigh wave phase velocity and ellipticity using USArray: constraining velocity and density structure in the upper
Double plane wave reverse time migration with plane wave Green's function
NASA Astrophysics Data System (ADS)
Zhao, Z.; Sen, M. K.; Stoffa, P. L.
2015-12-01
Reverse time migration (RTM) is effective in obtaining complex subsurface structures from seismic data. By solving the two-way wave equation, RTM can use entire wavefield for imaging. Although powerful computer are becoming available, the conventional pre-stack shot gather RTM is still computationally expensive. Solving forward and backward wavefield propagation for each source location and shot gather is extremely time consuming, especially for large seismic datasets. We present an efficient, accurate and flexible plane wave RTM in the frequency domain where we utilize a compressed plane wave dataset, known as the double plane wave (DPW) dataset. Provided with densely sampled seismic dataset, shot gathers can be decomposed into source and receiver plane wave components with minimal artifacts. The DPW RTM is derived under the Born approximation and utilizes frequency domain plane wave Green's function for imaging. Time dips in the shot profiles can help to estimate the range of plane wave components present in shot gathers. Therefore, a limited number of plane wave Green's functions are needed for imaging. Plane wave Green's functions can be used for imaging both source and receiver plane waves. Source and receiver reciprocity can be used for imaging plane wave components at no cost and save half of the computation time. As a result, the computational burden for migration is substantially reduced. Plane wave components can be migrated independently to recover specific targets with given dips, and ray parameter common image gathers (CIGs) can be generated after migration directly. The ray parameter CIGs can be used to justify the correctness of velocity models. Subsurface anisotropy effects can also be included in our imaging condition, provided with plane wave Green's functions in the anisotropic media.
LINCing complex functions at the nuclear envelope
Rothballer, Andrea; Schwartz, Thomas U.; Kutay, Ulrike
2013-01-01
Linker of nucleoskeleton and cytoskeleton (LINC) complexes span the double membrane of the nuclear envelope (NE) and physically connect nuclear structures to cytoskeletal elements. LINC complexes are envisioned as force transducers in the NE, which facilitate processes like nuclear anchorage and migration, or chromosome movements. The complexes are built from members of two evolutionary conserved families of transmembrane (TM) proteins, the SUN (Sad1/UNC-84) domain proteins in the inner nuclear membrane (INM) and the KASH (Klarsicht/ANC-1/SYNE homology) domain proteins in the outer nuclear membrane (ONM). In the lumen of the NE, the SUN and KASH domains engage in an intimate assembly to jointly form a NE bridge. Detailed insights into the molecular architecture and atomic structure of LINC complexes have recently revealed the molecular basis of nucleo-cytoskeletal coupling. They bear important implications for LINC complex function and suggest new potential and as yet unexplored roles, which the complexes may play in the cell. PMID:23324460
Recent progress on nuclear parton distribution functions
NASA Astrophysics Data System (ADS)
Hirai, M.; Kumano, S.; Saito, K.
2011-09-01
We report current status of global analyses on nuclear parton distribution functions (NPDFs). The optimum NPDFs are determined by analyzing high-energy nuclear reaction data. Due to limited experimental measurements, antiquark modifications have large uncertainties at x > 0.2 and gluon modifications cannot be determined. A nuclear modification difference between u and d quark distributions could be an origin of the long-standing NuTeV sin2θw anomaly. There is also an issue of nuclear modification differences between the structure functions of charged-lepton and neutrino reactions. Next, nuclear clustering effects are discussed in structure functions F2A as a possible explanation for an anomalous result in the 9Be nucleus at the Thomas Jefferson National Accelerator Facility (JLab). Last, tensor-polarized quark and antiquark distribution functions are extracted from HERMES data on the polarized structure function b1 of the deuteron, and they could be used for testing theoretical models and for proposing future experiments, for example, the one at JLab. Such measurements could open a new field of spin physics in spin-one hadrons.
Nuclear diffractive structure functions at high energies
Marquet,C.; Kowalski, H.; Lappi, T.; Venugopalan, R.
2008-08-08
A future high-energy electron-ion collider would explore the non-linear weakly-coupled regime of QCD, and test the Color Glass Condensate (CGC) approach to high-energy scattering. Hard diffraction in deep inelastic scattering off nuclei will provide many fundamental measurements. In this work, the nuclear diffractive structure function F{sub 2,A}{sup D} is predicted in the CGC framework, and the features of nuclear enhancement and suppression are discussed.
Nonstandard jump functions for radially symmetric shock waves
Baty, Roy S.; Tucker, Don H.; Stanescu, Dan
2008-10-01
Nonstandard analysis is applied to derive generalized jump functions for radially symmetric, one-dimensional, magnetogasdynamic shock waves. It is assumed that the shock wave jumps occur on infinitesimal intervals, and the jump functions for the physical parameters occur smoothly across these intervals. Locally integrable predistributions of the Heaviside function are used to model the flow variables across a shock wave. The equations of motion expressed in nonconservative form are then applied to derive unambiguous relationships between the jump functions for the physical parameters for two families of self-similar flows. It is shown that the microstructures for these families of radially symmetric, magnetogasdynamic shock waves coincide in a nonstandard sense for a specified density jump function
Boundary conditions on internal three-body wave functions
Mitchell, Kevin A.; Littlejohn, Robert G.
1999-10-01
For a three-body system, a quantum wave function {Psi}{sub m}{sup {ell}} with definite {ell} and m quantum numbers may be expressed in terms of an internal wave function {chi}{sub k}{sup {ell}} which is a function of three internal coordinates. This article provides necessary and sufficient constraints on {chi}{sub k}{sup {ell}} to ensure that the external wave function {Psi}{sub k}{sup {ell}} is analytic. These constraints effectively amount to boundary conditions on {chi}{sub k}{sup {ell}} and its derivatives at the boundary of the internal space. Such conditions find similarities in the (planar) two-body problem where the wave function (to lowest order) has the form r{sup |m|} at the origin. We expect the boundary conditions to prove useful for constructing singularity free three-body basis sets for the case of nonvanishing angular momentum.
Nonstandard jump functions for radically symmetric shock waves
Baty, Roy S; Tucker, Don H; Stanescu, Dan
2008-01-01
Nonstandard analysis is applied to derive generalized jump functions for radially symmetric, one-dimensional, magnetogasdynamic shock waves. It is assumed that the shock wave jumps occur on infinitesimal intervals and the jump functions for the physical parameters occur smoothly across these intervals. Locally integrable predistributions of the Heaviside function are used to model the flow variables across a shock wave. The equations of motion expressed in nonconservative form are then applied to derive unambiguous relationships between the jump functions for the physical parameters for two families of self-similar flows. It is shown that the microstructures for these families of radially symmetric, magnetogasdynamic shock waves coincide in a nonstandard sense for a specified density jump function.
Nuclear modifications of Parton Distribution Functions
NASA Astrophysics Data System (ADS)
Adeluyi, Adeola Adeleke
This dissertation addresses a central question of modern nuclear physics: how does the behavior of fundamental degrees of freedom (quarks and gluons) change in the nuclear environment? This is an important aspect of experimental studies at current facilities such as the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory and the Continuous Electron Beam Accelerator Facility (CEBAF) at the Thomas Jefferson National Laboratory (JLAB). It is also highly relevant to planned experimental efforts at the Large Hadron Collider (LHC) and the future Electron Ion Collider (EIC). All these facilities probe matter via collisions involving nuclei; thus complications arise due to the presence of the attendant nuclear medium. Theoretical efforts to understand and interpret experimental results from such collisions are therefore largely dependent on the resolution of this question. The development of nuclear physics demonstrates that theoretical description is most efficient in terms of the effective degrees of freedom relevant to the scale (energy) being probed. Thus at low energies, nuclei are described as bound states of protons and neutrons (nucleons). At higher energies, the nucleons are no longer elementary, but are revealed to possess an underlying substructure: they are made up of quarks and gluons, collectively termed partons. The mometum distributions of these partons in the nucleon are referred to as Parton Distribution Functions (PDFs). Parton distributions can be determined from experimental measurements of structure functions. The ratio of nuclear structure functions to nucleon structure functions (generically referred to as nuclear ratio) is a measure of the nuclear modifications of the free nucleon PDFs. Thus a study of the nuclear ratio suffices to gain an understanding of nuclear modifications. In this dissertation we aim to describe theoretically nuclear modifications in a restricted region where the nuclear ratio is less than unity, the so
Calculation of electron wave functions and refractive index of Ne
NASA Astrophysics Data System (ADS)
Zhu, Min; Liu, Wei; Zhang, Tao
2008-10-01
The radial wave functions of inner electron shell and outer electron shell of a Ne atom were obtained by the approximate analytical method and tested by calculating the ground state energy of the Ne atom. The equivalent volume of electron cloud and the refractive index of Ne were calculated. The calculated refractive index agrees well with the experimental result. Relationship between the refractive index and the wave function of Ne was discovered.
The Pion Renormalized Light-Cone Wave Function
NASA Astrophysics Data System (ADS)
Trawiński, Arkadiusz P.
2016-06-01
An approximate light-cone wave function for the pion effective quark-antiquark Fock sector corresponding to a small value of the renormalization group parameter is presented. The approximate wave function is motivated by the LF-holography and the quadratic confinement potential in the front form of Hamiltonian dynamics, which is in harmony with the linear confining potential in the instant form. The pion radius, decay constant and form-factor are also presented.
Structure of the number-projected BCS wave function
NASA Astrophysics Data System (ADS)
Dukelsky, J.; Pittel, S.; Esebbag, C.
2016-03-01
We study the structure of the number-projected BCS (PBCS) wave function in the particle-hole basis, displaying its similarities with coupled clusters theory (CCT). The analysis of PBCS together with several modifications suggested by the CCT wave function is carried out for the exactly solvable Richardson model involving a pure pairing Hamiltonian acting in a space of equally spaced, doubly degenerate levels. We point out the limitations of PBCS to describe the nonsuperconducting regime and suggest possible avenues for improvement.
Multi-time wave functions for quantum field theory
Petrat, Sören; Tumulka, Roderich
2014-06-15
Multi-time wave functions such as ϕ(t{sub 1},x{sub 1},…,t{sub N},x{sub N}) have one time variable t{sub j} for each particle. This type of wave function arises as a relativistic generalization of the wave function ψ(t,x{sub 1},…,x{sub N}) of non-relativistic quantum mechanics. We show here how a quantum field theory can be formulated in terms of multi-time wave functions. We mainly consider a particular quantum field theory that features particle creation and annihilation. Starting from the particle–position representation of state vectors in Fock space, we introduce multi-time wave functions with a variable number of time variables, set up multi-time evolution equations, and show that they are consistent. Moreover, we discuss the relation of the multi-time wave function to two other representations, the Tomonaga–Schwinger representation and the Heisenberg picture in terms of operator-valued fields on space–time. In a certain sense and under natural assumptions, we find that all three representations are equivalent; yet, we point out that the multi-time formulation has several technical and conceptual advantages. -- Highlights: •Multi-time wave functions are manifestly Lorentz-covariant objects. •We develop consistent multi-time equations with interaction for quantum field theory. •We discuss in detail a particular model with particle creation and annihilation. •We show how multi-time wave functions are related to the Tomonaga–Schwinger approach. •We show that they have a simple representation in terms of operator valued fields.
Nuclear power-plant safety functions
Corcoran, W.R.; Finnicum, D.J.; Hubbard, F.R. III; Musick, C.R.; Walzer, P.F.
1981-03-01
The concept of safety functions is discussed. Ten critical safety functions and the multiple success paths available for accomplishing them are described. Use of the safety function concept in the development of emergency procedures, operator training, and control-room displays provides a systematic approach and a hierarchy of protection that an operator can use to mitigate the consequences of an event. The safety function concept can also be applied to the design and analysis of nuclear plant systems and to the evaluation of past expierience.
Improved variational wave functions for few-body nuclei
Wiringa, R.B.; Arriaga, A.; Pandharipande, V.R.
1995-08-01
We continued to work on improvements to our variational wave functions for use in Monte Carlo calculations of few-body nuclei. These trial functions include central, spin, isospin, tensor, and spin-orbit two-body correlations and three-body correlations for the three-nucleon potential. In the last two years we studied a variety of extra three-body correlations. Our search for possible forms was guided by comparisons made with 34-channel Faddeev wave functions provided by the Los Alamos-Iowa group. The new trial functions reduce the discrepancy with exact Faddeev calculations in {sup 3}H and Green`s Function Monte Carlo (GFMC) calculations in {sup 4}He by about 40%. This work is now being written up for publication. We hope to use similar comparisons with GFMC calculations in the six-body nuclei to find further improvements for the light p-shell nuclei, where the variational wave functions are not as good.
The effect of meson wave function on heavy-quark fragmentation function
NASA Astrophysics Data System (ADS)
Moosavi Nejad, S. Mohammad
2016-05-01
We calculate the process-independent fragmentation functions (FFs) for a heavy quark to fragment into heavy mesons considering the effects of meson wave function. In all previous works, where the FFs of heavy mesons or heavy baryons were calculated, a delta function form was approximated for the wave function of hadrons. Here, for the first time, we consider a typical mesonic wave function which is different from the delta function and is the nonrelativistic limit of the solution of Bethe-Salpeter equation with the QCD kernel. We shall present our numerical results for the heavy FFs and show how the proposed wave function improves the previous results. As an example, we focus on the fragmentation function for c -quark to split into S -wave D^0 -meson and compare our results with experimental data from BELLE and CLEO.
MILLIMETER-WAVE MONITORING OF NUCLEAR WASTE GLASS MELTS - AN OVERVIEW
Molten glass characteristics of temperature, resistivity, and viscosity can be monitored reliably in the high temperature and chemically corrosive environment of nuclear waste glass melters using millimeter-wave sensor technology. Millimeter-waves are ideally suited for such meas...
Progress on nuclear modifications of structure functions
NASA Astrophysics Data System (ADS)
Kumano, S.
2016-03-01
We report progress on nuclear structure functions, especially on their nuclear modifications and a new tensor structure function for the deuteron. To understand nuclear structure functions is an important step toward describing nuclei and QCD matters from low to high densities and from low to high energies in terms of fundamental quark and gluon degrees of freedom beyond conventional hadron and nuclear physics. It is also practically important for understanding new phenomena in high-energy heavy-ion collisions at RHIC and LHC. Furthermore, since systematic errors of current neutrinooscillation experiments are dominated by uncertainties of neutrino-nucleus interactions, such studies are valuable for finding new physics beyond current framework. Next, a new tensor-polarized structure function b1 is discussed for the deuteron. There was a measurement by HERMES; however, its data are inconsistent with the conventional convolution estimate based on the standard deuteron model with D-state admixture. This fact suggests that a new hadronic phenomenon should exist in the tensor-polarized deuteron at high energies, and it will be experimentally investigated at JLab from the end of 2010's.
Nuclear moments in covariant density functional theory
NASA Astrophysics Data System (ADS)
Meng, J.; Zhao, P. W.; Zhang, S. Q.; Hu, J. N.; Li, J.
2014-05-01
Recent progresses on microscopic and self-consistent description of the nuclear moments in covariant density functional theory based on a point-coupling interaction are briefly reviewed. In particular, the electric quadrupole moments of Cd isotopes and the magnetic moments of Pb isotopes are discussed.
Parametric dependence of ocean wave-radar modulation transfer functions
NASA Technical Reports Server (NTRS)
Plant, W. J.; Keller, W. C.; Cross, A.
1983-01-01
Microwave techniques at X and L band were used to determine the dependence of ocean-wave radar modulation transfer functions (MTFs) on various environmental and radar parameters during the Marine Remote Sensing experiment of 1979 (MARSEN 79). These MIF are presented, as are coherence functions between the AM and FM parts of the backscattered microwave signal. It is shown that they both depend on several of these parameters. Besides confirming many of the properties of transfer functions reported by previous authors, indications are found that MTFs decrease with increasing angle between wave propagation and antenna-look directions but are essentially independent of small changes in air-sea temperature difference. However, coherence functions are much smaller when the antennas are pointed perpendicular to long waves. It is found that X band transfer functions measured with horizontally polarized microwave radiation have larger magnitudes than those obtained by using vertical polarization.
Mechanical regulation of nuclear structure and function.
Martins, Rui P; Finan, John D; Guilak, Farshid; Lee, David A
2012-01-01
Mechanical loading induces both nuclear distortion and alterations in gene expression in a variety of cell types. Mechanotransduction is the process by which extracellular mechanical forces can activate a number of well-studied cytoplasmic signaling cascades. Inevitably, such signals are transduced to the nucleus and induce transcription factor-mediated changes in gene expression. However, gene expression also can be regulated through alterations in nuclear architecture, providing direct control of genome function. One putative transduction mechanism for this phenomenon involves alterations in nuclear architecture that result from the mechanical perturbation of the cell. This perturbation is associated with direct mechanical strain or osmotic stress, which is transferred to the nucleus. This review describes the current state of knowledge relating the nuclear architecture and the transfer of mechanical forces to the nucleus mediated by the cytoskeleton, the nucleoskeleton, and the LINC (linker of the nucleoskeleton and cytoskeleton) complex. Moreover, remodeling of the nucleus induces alterations in nuclear stiffness, which may be associated with cell differentiation. These phenomena are discussed in relation to the potential influence of nuclear architecture-mediated mechanoregulation of transcription and cell fate. PMID:22655599
Nonlinear radiation damping of nuclear spin waves and magnetoelastic waves in antiferromagnets
NASA Astrophysics Data System (ADS)
Andrienko, Alexander V.; Safonov, Vladimir L.
2016-03-01
Parallel pumping of nuclear spin waves in antiferromagnetic CsMnF3 at liquid helium temperatures and magnetoelastic waves in antiferromagnetic FeBO3 at liquid nitrogen temperature in a helical resonator was studied. It was found that the absorbed microwave power is approximately equal to the irradiated power from the sample and that the main restriction mechanism of absorption in both cases is defined by the nonlinear radiation damping predicted about two decades ago. Nonlinear radiation damping is sure to be a common feature of the parallel pumping technique for all normal magnetic excitations and it must be taken into account for interpretation of nonlinear phenomena in parametrically excited magnetic systems.
Nuclear structure functions at small x
Jalilian-Marian, Jamal
2009-11-15
I study the nuclear structure function F{sub 2}{sup A} and its logarithmic derivative in the high-energy limit (small-x region) using the color glass condensate formalism. In this limit the structure function F{sub 2} depends on the quark-antiquark dipole-target scattering cross section N{sub F}(x{sub bj},r{sub t},b{sub t}). The same dipole cross section appears in single-hadron and hadron-photon production cross sections in the forward rapidity region in deuteron (proton)-nucleus collisions at high energy, that is, at energies available at the BNL Relativistic Heavy Ion Collider (RHIC) and the CERN Large Hadron Collider (LHC). I use a parametrization of the dipole cross section, which has successfully been used to describe the deuteron-gold data at the RHIC, to compute the nuclear structure function F{sub 2}{sup A} and its log Q{sup 2} derivative (which is related to gluon distribution function in the double log limit). I provide a quantitative estimate of the nuclear shadowing of F{sub 2}{sup A} and the gluon distribution function in the kinematic region relevant to a future electron-ion collider.
Pfaffian wave functions and topology of fermion nodes
NASA Astrophysics Data System (ADS)
Mitas, Lubos
2007-03-01
Pfaffian is defined as a signed sum of all pair partitions of even number of elements and it can be viewed as a nontrivial generalization of determinant. Pfaffian enables to define the simplest possible antisymmetric wave function based on pair spinorbital(s) and therefore represents a pairing generalization of the Slater determinant of one-particle orbitals. Pfaffians actually accomodate several types of pairing wave functions, for example, one special case is the Bardeen-Cooper- Schrieffer wave function. Using this platform we propose pfaffian wave functions with simultaneous pairings both in singlet and triplet channels and we benchmark their performance in fixed-node quantum Monte Carlo. We implement Gaussian elimination-like algorithm which enables to calculate pfaffians with efficiency similar to calculation of determinants. For a testing set of first row atoms and molecules we show that single pfaffians provide correlation energies systematically at the level of about 95%. Linear combinations of small number of pfaffians recover another fraction of the missing correlation energy comparable to significantly larger determinantal expansions. In addition, we show that pfaffians possess an important property of fermionic wave functions, namely, the minimal number of two nodal domains defined by fermion nodes. This is related to the proof that under rather general conditions closed-shell ground state wave functions of fermionic systems in d>1 have two nodal domains for arbitrary system size. The explicit proofs cover a number of paradigmatic models such as fermions on a sphere surface, in a periodic box, atomic states, etc, and we discuss the implications of this on efficient construction of wave functions and on several types of many-body effects. Supported by NSF and done in collaboration with M. Bajdich, L.K. Wagner, G. Drobny, and K.E Schmidt.Refs: L. Mitas, PRL 96, 240402 (2006); L. Mitas, cond-mat/0605550; M. Bajdich et al, PRL 96, 130201 (2006); cond
Rossby wave Green's functions in an azimuthal wind
NASA Astrophysics Data System (ADS)
Webb, G. M.; Duba, C. T.; Hu, Q.
2016-05-01
Green's functions for Rossby waves in an azimuthal wind are obtained, in which the stream-function $\\psi$ depends on $r$, $\\phi$ and $t$, where $r$ is cylindrical radius and $\\phi$ is the azimuthal angle in the $\\beta$-plane relative to the easterly direction, in which the $x$-axis points east and the $y$-axis points north. The Rossby wave Green's function with no wind is obtained using Fourier transform methods, and is related to the previously known Green's function obtained for this case, which has a different but equivalent form to the Green's function obtained in the present paper. We emphasize the role of the wave eikonal solution, which plays an important role in the form of the solution. The corresponding Green's function for a rotating wind with azimuthal wind velocity ${\\bf u}=\\Omega r{\\bf e}_\\phi$ ($\\Omega=$const.) is also obtained by Fourier methods, in which the advective rotation operator in position space is transformed to a rotation operator in ${\\bf k}$ transform space. The finite Rossby deformation radius is included in the analysis. The physical characteristics of the Green's functions are delineated and applications are discussed. In the limit as $\\Omega\\to 0$, the rotating wind Green's function reduces to the Rossby wave Green function with no wind.
Adjustment of Born-Oppenheimer electronic wave functions to simplify close coupling calculations.
Buenker, Robert J; Liebermann, Heinz-Peter; Zhang, Yu; Wu, Yong; Yan, Lingling; Liu, Chunhua; Qu, Yizhi; Wang, Jianguo
2013-04-30
Technical problems connected with use of the Born-Oppenheimer clamped-nuclei approximation to generate electronic wave functions, potential energy surfaces (PES), and associated properties are discussed. A computational procedure for adjusting the phases of the wave functions, as well as their order when potential crossings occur, is presented which is based on the calculation of overlaps between sets of molecular orbitals and configuration interaction eigenfunctions obtained at neighboring nuclear conformations. This approach has significant advantages for theoretical treatments describing atomic collisions and photo-dissociation processes by means of ab initio PES, electronic transition moments, and nonadiabatic radial and rotational coupling matrix elements. It ensures that the electronic wave functions are continuous over the entire range of nuclear conformations considered, thereby greatly simplifying the process of obtaining the above quantities from the results of single-point Born-Oppenheimer calculations. The overlap results are also used to define a diabatic transformation of the wave functions obtained for conical intersections that greatly simplifies the computation of off-diagonal matrix elements by eliminating the need for complex phase factors. PMID:23345171
Joint Resummation for TMD Wave Function of Pion
NASA Astrophysics Data System (ADS)
Wang, Yu-Ming
2015-02-01
QCD corrections to transverse-momentum-dependent pion wave function develop the mixed double logarithm ln x ln(ζ P2/k_T^2), when the gluon emission is collinear to the energetic pion. The fist scheme-independent kT factorization formula for γ*π → γ transition form factor is achieved by resumming all the enhanced logarithms for both pion wave function and short-distance coefficient function. High-order QCD corrections and transfer momentum √ {Q2} dependence of pion form factor are found to be distinct from those predicted by the conventional resummation approach.
Perturbations in vibrational diatomic spectra: Factorization of the molecular wave function
Lefebvre, R.
2015-02-21
The coupling between two electronic states of a diatomic molecule may lead to an erratic behaviour of the associated vibrational energies. An example is the homogeneous coupling between the valence b′ state and the Rydberg c′ state of the N{sub 2} molecule, both of symmetry {sup 1}Σ{sub u}{sup +}. The standard treatment of such a situation is to write the wave function as a sum of two Born-Oppenheimer products. It has recently been argued [L. S. Cederbaum, J. Chem. Phys. 138, 224110 (2013); N. I. Gidopoulos and E. K. U. Gross, Philos. Trans. R. Soc., A 372, 20130059 (2014)] that even in such a case the wave function should be representable as a single product, with an electronic factor depending parametrically on nuclear positions and a nuclear factor. We setup such a representation in the case of the perturbations in the N{sub 2} molecule.
Building a Universal Nuclear Energy Density Functional
Carlson, Joe A.; Furnstahl, Dick; Horoi, Mihai; Lust, Rusty; Nazaewicc, Witek; Ng, Esmond; Thompson, Ian; Vary, James
2012-12-30
During the period of Dec. 1 2006 – Jun. 30, 2012, the UNEDF collaboration carried out a comprehensive study of all nuclei, based on the most accurate knowledge of the strong nuclear interaction, the most reliable theoretical approaches, the most advanced algorithms, and extensive computational resources, with a view towards scaling to the petaflop platforms and beyond. The long-term vision initiated with UNEDF is to arrive at a comprehensive, quantitative, and unified description of nuclei and their reactions, grounded in the fundamental interactions between the constituent nucleons. We seek to replace current phenomenological models of nuclear structure and reactions with a well-founded microscopic theory that delivers maximum predictive power with well-quantified uncertainties. Specifically, the mission of this project has been three-fold: First, to find an optimal energy density functional (EDF) using all our knowledge of the nucleonic Hamiltonian and basic nuclear properties; Second, to apply the EDF theory and its extensions to validate the functional using all the available relevant nuclear structure and reaction data; Third, to apply the validated theory to properties of interest that cannot be measured, in particular the properties needed for reaction theory.
Expansion of X-ray form factor for close shell using uncorrelated wave function
AL-Robayi, Enas M.
2013-12-16
The atomic scattering factor has been studied for Be+ve, and B+2ve ions using the uncorrelated wave function (Hartree-Fock (HF)) for inter particle electronic shells. The physical importance of this factor appears in its relation to several important atomic properties as, the coherent scattering intensity, the total scattering intensity, the incoherent scattering function, the coherent scattering cross section, the total incoherent cross section, the nuclear magnetic shielding constant, the geometrical structure factor. Also there is one atomic properties the one particle radial density distribution function D(r)has been studied using the partitioning technique.
Evolution of wave function in a dissipative system
NASA Technical Reports Server (NTRS)
Yu, Li-Hua; Sun, Chang-Pu
1994-01-01
For a dissipative system with Ohmic friction, we obtain a simple and exact solution for the wave function of the system plus the bath. It is described by the direct product in two independent Hilbert space. One of them is described by an effective Hamiltonian, the other represents the effect of the bath, i.e., the Brownian motion, thus clarifying the structure of the wave function of the system whose energy is dissipated by its interaction with the bath. No path integral technology is needed in this treatment. The derivation of the Weisskopf-Wigner line width theory follows easily.
Two-dimensional Coulomb scattering of a quantum particle: Wave functions and Green's functions
NASA Astrophysics Data System (ADS)
Pupyshev, V. V.
2016-02-01
We solve the problem of the propagation of a charged quantum particle in a two-dimensional plane embedded in the three-dimensional coordinate space. We consider scattering of this particle by a stable Coulomb center situated in the same plane. We study the wave function of this particle, its Green's function, and all radial components of these functions. We derive uniform majorant bounds on absolute values of these functions and find the wave function representation in terms of regular radial Coulomb functions and the scattering amplitude representation via partial phases. We obtain integral representations of the Greens's function and all its radial components.
Nuclear parton distribution functions and their uncertainties
Hirai, M.; Kumano, S.; Nagai, T.-H.
2004-10-01
We analyze experimental data of nuclear structure-function ratios F{sub 2}{sup A}/F{sub 2}{sup A{sup '}} and Drell-Yan cross section ratios for obtaining optimum parton distribution functions (PDFs) in nuclei. Then, uncertainties of the nuclear PDFs are estimated by the Hessian method. Valence-quark distributions are determined by the F{sub 2} data at large x; however, the small-x part is not obvious from the data. On the other hand, the antiquark distributions are determined well at x{approx}0.01 from the F{sub 2} data and at x{approx}0.1 by the Drell-Yan data; however, the large-x behavior is not clear. Gluon distributions cannot be fixed by the present data and they have large uncertainties in the whole x region. Parametrization results are shown in comparison with the data. We provide a useful code for calculating nuclear PDFs at given x and Q{sup 2}.
Green's function Monte Carlo in nuclear physics
Carlson, J.
1990-01-01
We review the status of Green's Function Monte Carlo (GFMC) methods as applied to problems in nuclear physics. New methods have been developed to handle the spin and isospin degrees of freedom that are a vital part of any realistic nuclear physics problem, whether at the level of quarks or nucleons. We discuss these methods and then summarize results obtained recently for light nuclei, including ground state energies, three-body forces, charge form factors and the coulomb sum. As an illustration of the applicability of GFMC to quark models, we also consider the possible existence of bound exotic multi-quark states within the framework of flux-tube quark models. 44 refs., 8 figs., 1 tab.
Hydrodynamic waves and correlation functions in dusty plasmas
Wang, X.; Bhattacharjee, A.
1997-11-01
A hydrodynamic description of strongly coupled dusty plasmas is given when physical quantities vary slowly in space and time and the system can be assumed to be in local thermodynamic equilibrium. The linear waves in such a system are analyzed. In particular, a dispersion equation is derived for low-frequency dust acoustic waves, including collisional damping effects, and compared with experimental results. The linear response of the system is calculated from the fluctuation-dissipation theorem and the hydrodynamic equations. The requirement that these two calculations coincide constrains the particle correlation function for slowly varying perturbations. It is shown that in the presence of weakly damped, long-wavelength dust-acoustic waves, the dust autocorrelation function is of the Debye{endash}H{umlt u}ckel form and the characteristic shielding distance is the dust Debye length. {copyright} {ital 1997 American Institute of Physics.}
Oblique propagation, wave particle interaction and particle distribution function
NASA Astrophysics Data System (ADS)
Osmane, Adnane; Hamza, A. M.; Meziane, Karim
Recent results from the Cluster mission have stimulated theoretical investigations and simulations to explain ion distribution functions observed in the quasi-perp bow shock. High-time resolution observations have revealed distributions of gyrating ions that are gyrophase-bunched. When not produced at the shock, such distributions are believed to be resulting from interactions between field-aligned beams and low frequency beamdriven waves . The Conventional models used to account for such distributions assume that the waves are purely transverse, and that they propagate parallel to the ambient magnetic eld. However observations indicate that these waves are propagating obliquely with respect to the ambient magnetic eld [Meziane et al., 2001]. A theoretical investigation of the non-relativistic wave-particle interaction in a background magnetic eld with the electromagnetic wave propagating obliquely has been addressed previously, resulting in a dynamical system describing the wave interaction with a single ion in the absence of dissipation mechanisms. [Hamza et al., 2005] This dynamical system has been numerically integrated to construct the ion distribution functions by seeding the particles with di erent initial conditions. We compute the particle orbits and simulate the time evolution of the distribution functions based on Liouville's theorem of phase space density conservation. It will be shown that the trapping which is due to the oblique propagation of the wave, gives an explanation for gyrophase-bunching and unstable distributions in velocity space which could trigger instabilities such as firehose and mirror. Therefore this exercise provide insights on the particle dynamics and onset of waves away from the shock. Meziane, K., C. Mazelle, R.P. Lin, D. LeQueau, D.E. Larson, G.K. Parks, R.P. Lepping (2001), Three dimensional observations of gyrating ions distributions far upstream from the Earth's bow shock and their association with low-frequency waves, J
Source Time Function of P-wave Acceleration
NASA Astrophysics Data System (ADS)
Chen, K. J.
2015-12-01
In this study, the site effect of time function of the Taiwan area will be invested. The recorded response function of a single earthquake will be calculated by Complex Demodulation. The path effect of each event-station pair will be estimated by using the forward method with a 3-D attenuation structure. After removing the path effect, the source frequency function of each single event will be obtained by averaging the whole station gotten. Using this source time function to calculate the path effect of the all stations, the theoretic received time frequency function can be obtained. The difference between this theoretic function and the recorded function is the site effect function of the single station. The characterics of the site effect in Taiwan area will be analyzed. Recalculate the path effect and remove the site effect of each station to get the new source time function of P-wave acceleration.
Dark energy and normalization of the cosmological wave function
NASA Astrophysics Data System (ADS)
Huang, Peng; Huang, Yue; Li, Miao; Li, Nan
2016-08-01
Dark energy is investigated from the perspective of quantum cosmology. It is found that, together with an appropriate normal ordering factor q, only when there is dark energy can the cosmological wave function be normalized. This interesting observation may require further attention.
Simulation of wind wave growth with reference source functions
NASA Astrophysics Data System (ADS)
Badulin, Sergei I.; Zakharov, Vladimir E.; Pushkarev, Andrei N.
2013-04-01
We present results of extensive simulations of wind wave growth with the so-called reference source function in the right-hand side of the Hasselmann equation written as follows First, we use Webb's algorithm [8] for calculating the exact nonlinear transfer function Snl. Second, we consider a family of wind input functions in accordance with recent consideration [9] ( )s S = ?(k)N , ?(k) = ? ? ?- f (?). in k 0 ?0 in (2) Function fin(?) describes dependence on angle ?. Parameters in (2) are tunable and determine magnitude (parameters ?0, ?0) and wave growth rate s [9]. Exponent s plays a key role in this study being responsible for reference scenarios of wave growth: s = 4-3 gives linear growth of wave momentum, s = 2 - linear growth of wave energy and s = 8-3 - constant rate of wave action growth. Note, the values are close to ones of conventional parameterizations of wave growth rates (e.g. s = 1 for [7] and s = 2 for [5]). Dissipation function Sdiss is chosen as one providing the Phillips spectrum E(?) ~ ?5 at high frequency range [3] (parameter ?diss fixes a dissipation scale of wind waves) Sdiss = Cdissμ4w?N (k)θ(? - ?diss) (3) Here frequency-dependent wave steepness μ2w = E(?,?)?5-g2 makes this function to be heavily nonlinear and provides a remarkable property of stationary solutions at high frequencies: the dissipation coefficient Cdiss should keep certain value to provide the observed power-law tails close to the Phillips spectrum E(?) ~ ?-5. Our recent estimates [3] give Cdiss ? 2.0. The Hasselmann equation (1) with the new functions Sin, Sdiss (2,3) has a family of self-similar solutions of the same form as previously studied models [1,3,9] and proposes a solid basis for further theoretical and numerical study of wave evolution under action of all the physical mechanisms: wind input, wave dissipation and nonlinear transfer. Simulations of duration- and fetch-limited wind wave growth have been carried out within the above model setup to check its
Correlated Strength in the Nuclear Spectral Function
D. Rohe; C. S. Armstrong; R. Asaturyan; O. K. Baker; S. Bueltmann; C. Carasco; D. Day; R. Ent; H. C. Fenker; K. Garrow; A. Gasparian; P. Gueye; M. Hauger; A. Honegger; J. Jourdan; C. E. Keppel; G. Kubon; R. Lindgren; A. Lung; D. J. Mack; J. H. Mitchell; H. Mkrtchyan; D. Mocelj; K. Normand; T. Petitjean; O. Rondon; E. Segbefia; I. Sick; S. Stepanyan; L. Tang; F. Tiefenbacher; W. F. Vulcan; G. Warren; S. A. Wood; L. Yuan; M. Zeier; H. Zhu; B. Zihlmann
2004-10-01
We have carried out an (e,ep) experiment at high momentum transfer and in parallel kinematics to measure the strength of the nuclear spectral function S(k,E) at high nucleon momenta k and large removal energies E. This strength is related to the presence of short-range and tensor correlations, and was known hitherto only indirectly and with considerable uncertainty from the lack of strength in the independent-particle region. This experiment locates by direct measurement the correlated strength predicted by theory.
Vector Meson Form Factors and Wave Functions from Holographic QCD
Hovhannes Grigoryan; Anatoly Radyushkin
2007-10-10
Based on the holographic dual model of QCD, we study 2- and 3-point functions of vector currents and derive form factors as well as wave functions for the vector mesons. As a result, generalized vector-meson dominance representation for form factors is obtained with a very specific VMD pattern. The calculated electric radius of the rho-meson is shown to be in a good agreement with predictions from lattice QCD.
Refined applications of the collapse of the wave function
NASA Astrophysics Data System (ADS)
Stodolsky, L.
2015-05-01
In a two-part system, the collapse of the wave function of one part can put the other part in a state which would be difficult or impossible to achieve otherwise, in particular, one sensitive to small effects in the "collapse" interaction. We present some applications to the very symmetric and experimentally accessible situations of the decays ϕ (1020 )→KoKo , ψ (3770 )→DoDo, or ϒ (4 s )→BoBo , involving the internal state of the two-state Ko, Do, or Bo mesons. The collapse of the wave function occasioned by a decay of one member of the pair (away side) fixes the state vector of that side's two-state system. Bose-Einstein statistics then determines the state of the recoiling meson (near side), whose evolution can then be followed further. In particular, the statistics requirement dictates that the "away side" and "near side" internal wave functions must be orthogonal at the time of the collapse. Thus a C P violation in the away side decay implies a complementary C P impurity on the near side, which can be detected in the further evolution. The C P violation so manifested is necessarily direct C P violation, since neither the mass matrix nor time evolution was involved in the collapse. A parametrization of the direct C P violation is given, and various manifestations are presented. Certain rates or combination of rates are identified which are nonzero only if there is direct C P violation. The very explicit and detailed use made of the collapse of the wave function makes the procedure interesting with respect to the fundamentals of quantum mechanics. We note an experimental consistency test for our treatment of the collapse of the wave function, which can be carried out by a certain measurement of partial decay rates.
How close can we get waves to wave functions, including potential?
NASA Astrophysics Data System (ADS)
Faletič, Sergej
2016-05-01
In the following article we show that mechanical waves on a braced string can have the same shapes as important wave functions in introductory quantum mechanics. A braced string is a string with additional transversal springs that serve as external "potential". The aim is not to suggest teaching quantum mechanics with these analogies. Instead, the aim is to provide students with some additional relevant experience in wave mechanics before they are introduced to quantum mechanics. We show how this experience can be used in a constructivist sense as the basis for building quantum concepts. We consider energy transfer along such string and show that penetration of a wave into a region with high "potential" is not unexpected. We also consider energy transfer between two such strings and show that it can appear point-like even though the wave is an extended object. We also suggest that applying quantization of energy transfer to wave phenomena can explain some of the more difficult to accept features of quantum mechanics.
Occupation-number-based energy functional for nuclear masses
Bertolli, Michael G.; Papenbrock, Thomas F; Wild, S. M.
2012-01-01
We develop an energy functional with shell-model occupations as the relevant degrees of freedom and compute nuclear masses across the nuclear chart. The functional is based on Hohenberg-Kohn theory with phenomenologically motivated terms. A global fit of the 17-parameter functional to 2049 nuclear masses yields a root-mean-square deviation of =1.31 MeV. Nuclear radii are computed within a model that employs the resulting occupation numbers.
Occupation number-based energy functional for nuclear masses.
Bertolli, M.; Papenbrock, T.; Wild, S. M.
2012-01-01
We develop an energy functional with shell-model occupations as the relevant degrees of freedom and compute nuclear masses across the nuclear chart. The functional is based on Hohenberg-Kohn theory with phenomenologically motivated terms. A global fit of the 17-parameter functional to 2049 nuclear masses yields a root-mean-square deviation of {chi} = 1.31 MeV. Nuclear radii are computed within a model that employs the resulting occupation numbers.
Local properties of three-body atomic wave functions
Krivec, R.; Mandelzweig, V. B.; Varga, K.
2000-06-01
The local properties and accuracy of the positronium negative-ion (Ps{sup -}) ground-state wave functions obtained by the stochastic variational method (SVM) and by direct solution of the Schroedinger equation with the help of the correlation-function hyperspherical-harmonic method (CFHHM) are studied and compared. Though the energy, calculated by both methods, agrees to up to ten digits, the amplitudes of the values of the operator D=H{psi}/E{psi}-1, characterizing local deviation of the wave function from its true value, in all of the coordinate space in the SVM are consistently larger (by up to five orders of magnitude) than in the CFHHM, despite the fact that the SVM observables except <{delta}(r{sub k})> converge to significantly more digits than the CFHHM observables for their respective selected bases. (c) 2000 The American Physical Society.
Edge states for the Kalmeyer-Laughlin wave function
NASA Astrophysics Data System (ADS)
Herwerth, Benedikt; Sierra, Germán; Tu, Hong-Hao; Cirac, J. Ignacio; Nielsen, Anne E. B.
2015-12-01
We study lattice wave functions obtained from the SU(2)1 Wess-Zumino-Witten conformal field theory. Following Moore and Read's construction, the Kalmeyer-Laughlin fractional quantum Hall state is defined as a correlation function of primary fields. By an additional insertion of Kac-Moody currents, we associate a wave function with each state of the conformal field theory. These wave functions span the complete Hilbert space of the lattice system. On the cylinder, we study global properties of the lattice states analytically and correlation functions numerically using a Metropolis Monte Carlo method. By comparing short-range bulk correlations, numerical evidence is provided that the states with one current operator represent edge states in the thermodynamic limit. We show that the edge states with one Kac-Moody current of lowest order have a good overlap with low-energy excited states of a local Hamiltonian, for which the Kalmeyer-Laughlin state approximates the ground state. For some states, exact parent Hamiltonians are derived on the cylinder. These Hamiltonians are SU(2) invariant and nonlocal with up to four-body interactions.
[Nuclear medicine for evaluation of liver functions].
Yamamoto, K
1994-05-01
The clinical usefulness of colloid liver scintigraphy to detect space occupying lesions in the liver has been reduced by X-ray CT and ultrasonography. However, scintigraphic examinations have potentials for characteristic diagnosis of liver tumors, such as 99mTc RBC SPECT for hepatic hemangioma, 99mTc PMT for positive imaging of hepatocellular carcinoma and its extrahepatic metastasis, and radioimmunoscintigraphy for metastatic tumors. Moreover, prediction of the prognosis and monitoring therapeutic effect to liver cancer can be made by the use of nuclear medicine techniques. Recently, 99mTc galactosyl serum albumin (GSA), a newly developed radiotracer to evaluate hepatocyte function, has become commercially available. Quantitative parameters of liver functions can be obtained by analysis of time-activity curve in blood and liver after 99mTc-GSA administration. In several cases, 99mTc-GSA study showed intrahepatic unevenness of function, which could not be depicted by other imaging examinations. Positron emission tomography (PET) with 18F-fluoro-2-deoxy glucose (FDG) is useful to detect malignant tumors in the liver. Since PET can provide absolutely quantitative data in better resolution, it is expected that regional true metabolic functions in the liver may be able to be quantitatively evaluated with PET in near future. PMID:8028225
Probing the wave function of shallow Li and Na donors in ZnO nanoparticles.
Orlinskii, Serguei B; Schmidt, Jan; Baranov, Pavel G; Hofmann, Detlev M; de Mello Donegá, Celso; Meijerink, Andries
2004-01-30
Electron paramagnetic resonance and electron nuclear double resonance (ENDOR) experiments on ZnO nanoparticles reveal the presence of shallow donors related to interstitial Li and Na atoms. The shallow character of the wave function is evidenced by the multitude of 67Zn ENDOR lines and further by the hyperfine interactions with the 7Li and 23Na nuclei that are much smaller than for atomic lithium and sodium. In the case of the Li-doped nanoparticles, an increase of the hyperfine interaction with the 7Li nucleus and with the 1H nuclei in the Zn(OH)(2) capping layer is observed when reducing the size of the nanoparticles. This effect is caused by the confinement of the shallow-donor 1s-type wave function that has a Bohr radius of about 1.5 nm, i.e., comparable to the dimension of the nanoparticles. PMID:14995405
Probing the Wave Function of Shallow Li and Na Donors in ZnO Nanoparticles
NASA Astrophysics Data System (ADS)
Orlinskii, Serguei B.; Schmidt, Jan; Baranov, Pavel G.; Hofmann, Detlev M.; de Mello Donegá, Celso; Meijerink, Andries
2004-01-01
Electron paramagnetic resonance and electron nuclear double resonance (ENDOR) experiments on ZnO nanoparticles reveal the presence of shallow donors related to interstitial Li and Na atoms. The shallow character of the wave function is evidenced by the multitude of 67Zn ENDOR lines and further by the hyperfine interactions with the 7Li and 23Na nuclei that are much smaller than for atomic lithium and sodium. In the case of the Li-doped nanoparticles, an increase of the hyperfine interaction with the 7Li nucleus and with the 1H nuclei in the Zn(OH)2 capping layer is observed when reducing the size of the nanoparticles. This effect is caused by the confinement of the shallow-donor 1s-type wave function that has a Bohr radius of about 1.5nm, i.e., comparable to the dimension of the nanoparticles.
Resonating valence bond wave functions and classical interacting dimer models.
Damle, Kedar; Dhar, Deepak; Ramola, Kabir
2012-06-15
We relate properties of nearest-neighbor resonating valence-bond (NNRVB) wave functions for SU(g) spin systems on two-dimensional bipartite lattices to those of fully packed interacting classical dimer models on the same lattice. The interaction energy can be expressed as a sum of n-body potentials V(n), which are recursively determined from the NNRVB wave function on finite subgraphs of the original lattice. The magnitude of the n-body interaction V(n) (n>1) is of order O(g(-(n-1))) for small g(-1). The leading term is a two-body nearest-neighbor interaction V2(g) favoring two parallel dimers on elementary plaquettes. For SU(2) spins, using our calculated value of V2(g=2), we find that the long-distance behavior of the bond-energy correlation function is dominated by an oscillatory term that decays as 1/|r|α with α≈1.22. This result is in remarkable quantitative agreement with earlier direct numerical studies of the corresponding wave function, which give α≈1.20. PMID:23004328
The Nuclear Energy Density Functional Formalism
NASA Astrophysics Data System (ADS)
Duguet, T.
The present document focuses on the theoretical foundations of the nuclear energy density functional (EDF) method. As such, it does not aim at reviewing the status of the field, at covering all possible ramifications of the approach or at presenting recent achievements and applications. The objective is to provide a modern account of the nuclear EDF formalism that is at variance with traditional presentations that rely, at one point or another, on a Hamiltonian-based picture. The latter is not general enough to encompass what the nuclear EDF method represents as of today. Specifically, the traditional Hamiltonian-based picture does not allow one to grasp the difficulties associated with the fact that currently available parametrizations of the energy kernel E[g',g] at play in the method do not derive from a genuine Hamilton operator, would the latter be effective. The method is formulated from the outset through the most general multi-reference, i.e. beyond mean-field, implementation such that the single-reference, i.e. "mean-field", derives as a particular case. As such, a key point of the presentation provided here is to demonstrate that the multi-reference EDF method can indeed be formulated in a mathematically meaningful fashion even if E[g',g] does not derive from a genuine Hamilton operator. In particular, the restoration of symmetries can be entirely formulated without making any reference to a projected state, i.e. within a genuine EDF framework. However, and as is illustrated in the present document, a mathematically meaningful formulation does not guarantee that the formalism is sound from a physical standpoint. The price at which the latter can be enforced as well in the future is eventually alluded to.
Estimating Moho depth utilizing S-wave receiver functions
NASA Astrophysics Data System (ADS)
Ceylan, S.; Rychert, C.; Harmon, N.
2014-12-01
H-k stacking method [Zhu and Kanamori, 2000] is a widely used grid search technique for estimating the Moho depth (H) and Vp/Vs (k) beneath a given station. The H-k surface reaches a maximum when the optimum H and k values are used, which is assumed to be the average crustal structure beneath the seismic station. In general, the method is employed in conjunction with P-wave receiver functions. Here, we investigate the usability of H-k stacking method with S-to-P (Sp) conversions and S-wave reverberations within the crust, employing an extended multi-taper deconvolution. We apply the method to southern California, using data recorded between 1990-2011. We compare results with those of prior studies that used P-to-S (Ps) conversions [Zhu and Kanamori, 2000; Yan and Clayton, 2007], applying a smoothing length of 0.5 degrees to reflect lateral Sp sensitivity. P-waves have better potential to resolve lateral variations in Moho depth owing to the higher frequency content and the geometry of Ps ray path. Our results from Sp conversions are in broad agreement with those from Ps, affirming that S-wave receiver functions can be used in conjunction with the H-k stacking method. Consistent with the P-wave receiver function results, crust is thinner beneath the central Transverse Range (30 km) with respect to eastern Transverse Range (33 km) and Peninsular Region (35 km). Our Moho depth observations (35 km) are more compatible with those of Yan and Clayton [2007] (~35 km) than Zhu and Kanamori [2000] (~30 km) beneath Sierra Nevada, most probably due to a larger data set this study and Yan and Clayton [2007] use. Also, results from this study are deeper than those from Ps for the Salton Trough (30-35 km vs. 25 km). In this case, broad receiver function waveform characteristics suggest a more gradual impedance change across the Moho discontinuity and/or a multi-layered crust. We suggest that a combination of P- and S-wave receiver functions can yield more robust crustal thickness
Configuration interaction wave functions: A seniority number approach
Alcoba, Diego R.; Torre, Alicia; Lain, Luis; Massaccesi, Gustavo E.; Oña, Ofelia B.
2014-06-21
This work deals with the configuration interaction method when an N-electron Hamiltonian is projected on Slater determinants which are classified according to their seniority number values. We study the spin features of the wave functions and the size of the matrices required to formulate states of any spin symmetry within this treatment. Correlation energies associated with the wave functions arising from the seniority-based configuration interaction procedure are determined for three types of molecular orbital basis: canonical molecular orbitals, natural orbitals, and the orbitals resulting from minimizing the expectation value of the N-electron seniority number operator. The performance of these bases is analyzed by means of numerical results obtained from selected N-electron systems of several spin symmetries. The comparison of the results highlights the efficiency of the molecular orbital basis which minimizes the mean value of the seniority number for a state, yielding energy values closer to those provided by the full configuration interaction procedure.
Configuration interaction wave functions: A seniority number approach
NASA Astrophysics Data System (ADS)
Alcoba, Diego R.; Torre, Alicia; Lain, Luis; Massaccesi, Gustavo E.; Oña, Ofelia B.
2014-06-01
This work deals with the configuration interaction method when an N-electron Hamiltonian is projected on Slater determinants which are classified according to their seniority number values. We study the spin features of the wave functions and the size of the matrices required to formulate states of any spin symmetry within this treatment. Correlation energies associated with the wave functions arising from the seniority-based configuration interaction procedure are determined for three types of molecular orbital basis: canonical molecular orbitals, natural orbitals, and the orbitals resulting from minimizing the expectation value of the N-electron seniority number operator. The performance of these bases is analyzed by means of numerical results obtained from selected N-electron systems of several spin symmetries. The comparison of the results highlights the efficiency of the molecular orbital basis which minimizes the mean value of the seniority number for a state, yielding energy values closer to those provided by the full configuration interaction procedure.
Hydrodynamic Waves and Correlation Functions in Dusty Plasmas
NASA Astrophysics Data System (ADS)
Bhattacharjee, A.; Wang, Xiaogang
1997-11-01
A hydrodynamic description of strongly coupled dusty plasmas is given when physical quantities vary slowly in space and time and the system can be assumed to be in local thermodynamic equilibrium. The linear waves in such a system are analyzed. In particular, a dispersion equation is derived for low-frequency dust acoustic waves, including collisional damping effects, and compared with experimental results. The linear response of the system is calculated from the fluctuation-dissipation theorem and the hydrodynamic equations. The requirement that these two calculations coincide constrains the particle correlation function for slowly varying perturbations [L. P. Kadanoff and P. C. Martin, Ann. Phys. 24, 419 (1963)]. It is shown that in the presence of the slow dust-acoustic waves, the dust auto-correlation function is of the Debye-Hekel form and the shielding distance is the dust Debye length. In the short-wavelength regime, an integral equation is derived from kinetic theory and solved numerically to yield particle correlation functions that display ``liquid-like'' behavior and have been observed experimentally [R. A.. Quinn, C. Cui, J. Goree, J. B. Pieper, H. Thomas and G. E. Morfill, Phys. Rev. E 53, R2049 (1996)].
Computational aspects of the continuum quaternionic wave functions for hydrogen
Morais, J.
2014-10-15
Over the past few years considerable attention has been given to the role played by the Hydrogen Continuum Wave Functions (HCWFs) in quantum theory. The HCWFs arise via the method of separation of variables for the time-independent Schrödinger equation in spherical coordinates. The HCWFs are composed of products of a radial part involving associated Laguerre polynomials multiplied by exponential factors and an angular part that is the spherical harmonics. In the present paper we introduce the continuum wave functions for hydrogen within quaternionic analysis ((R)QHCWFs), a result which is not available in the existing literature. In particular, the underlying functions are of three real variables and take on either values in the reduced and full quaternions (identified, respectively, with R{sup 3} and R{sup 4}). We prove that the (R)QHCWFs are orthonormal to one another. The representation of these functions in terms of the HCWFs are explicitly given, from which several recurrence formulae for fast computer implementations can be derived. A summary of fundamental properties and further computation of the hydrogen-like atom transforms of the (R)QHCWFs are also discussed. We address all the above and explore some basic facts of the arising quaternionic function theory. As an application, we provide the reader with plot simulations that demonstrate the effectiveness of our approach. (R)QHCWFs are new in the literature and have some consequences that are now under investigation.
Spin-orbit interaction with nonlinear wave functions.
Brozell, S. R.; Shepard, R.; Zhang, Z.; Stanford Univ.
2007-12-01
The computation of the spin-orbit interaction is discussed for electronic wave functions expressed in the new nonlinear expansion form. This form is based on spin eigenfunctions using the graphical unitary group approach (GUGA). The nodes of a Shavitt graph in GUGA are connected by arcs, and a Configuration State Function (CSF) is represented as a walk along arcs from the vacuum node to a head node. The wave function is a linear combination of product functions each of which is a linear combination of all CSFs, wherein each CSF coefficient is a product of nonlinear arc factors. When the spin-orbit interaction is included the Shavitt graph is a union of single-headed Shavitt graphs each with the same total number of electrons and orbitals. Thus spin-orbit Shavitt graphs are multiheaded. For full-CI multiheaded Shavitt graphs, analytic expressions are presented for the number of walks, the number of nodes, the number of arcs, and the number of node pairs in the associated auxiliary pair graph.
Orbital dependent functionals: An atom projector augmented wave method implementation
NASA Astrophysics Data System (ADS)
Xu, Xiao
This thesis explores the formulation and numerical implementation of orbital dependent exchange-correlation functionals within electronic structure calculations. These orbital-dependent exchange-correlation functionals have recently received renewed attention as a means to improve the physical representation of electron interactions within electronic structure calculations. In particular, electron self-interaction terms can be avoided. In this thesis, an orbital-dependent functional is considered in the context of Hartree-Fock (HF) theory as well as the Optimized Effective Potential (OEP) method and the approximate OEP method developed by Krieger, Li, and Iafrate, known as the KLI approximation. In this thesis, the Fock exchange term is used as a simple well-defined example of an orbital-dependent functional. The Projected Augmented Wave (PAW) method developed by P. E. Blochl has proven to be accurate and efficient for electronic structure calculations for local and semi-local functions because of its accurate evaluation of interaction integrals by controlling multiple moments. We have extended the PAW method to treat orbital-dependent functionals in Hartree-Fock theory and the Optimized Effective Potential method, particularly in the KLI approximation. In the course of study we develop a frozen-core orbital approximation that accurately treats the core electron contributions for above three methods. The main part of the thesis focuses on the treatment of spherical atoms. We have investigated the behavior of PAW-Hartree Fock and PAW-KLI basis, projector, and pseudopotential functions for several elements throughout the periodic table. We have also extended the formalism to the treatment of solids in a plane wave basis and implemented PWPAW-KLI code, which will appear in future publications.
Irregular wave functions of a hydrogen atom in a uniform magnetic field
NASA Technical Reports Server (NTRS)
Wintgen, D.; Hoenig, A.
1989-01-01
The highly excited irregular wave functions of a hydrogen atom in a uniform magnetic field are investigated analytically, with wave function scarring by periodic orbits considered quantitatively. The results obtained confirm that the contributions of closed classical orbits to the spatial wave functions vanish in the semiclassical limit. Their disappearance, however, is slow. This discussion is illustrated by numerical examples.
A Critical Examination of Wind-Wave Spectral Functional Form
NASA Technical Reports Server (NTRS)
Huang, Norden E.; Long, Steven R.
1999-01-01
Traditionally, data from random ocean waves are presented in spectral functions. The spectra are the result of Fourier analysis. Fourier spectral analysis has dominated data analysis for, at least, the last hundred years. It has been the standard method for is examining the global amplitude-frequency distributions. Although Fourier transform valid under extremely general conditions, there are some crucial restrictions for the Fourier spectral analysis. The system must be linear, and the data must be stationary- otherwise, the resulting spectrum will make little physical sense. The stationarity requirement is also a common required criterion for most of other available data analysis methods. Nevertheless, few, if any, natural phenomena are linear and stationary. To compound these complications is the imperfection of our probes or numerical schemes the interactions of the imperfect probes even with a perfect linear system can make the final data nonlinear. Furthermore, all the available data are usually of finite duration. Under these conditions, Fourier analysis is of limited use, For lack of alternatives, however, Fourier analysis is still used to process such data. The loose application of Fourier analysis and the insouciant adoption of the stationary and linear assumptions may lead to misleading conclusions. Ocean waves are know to be nonlinear, and the wind system generating the wave field are seldom stationary- As a result, the traditional examination of the spectral form hardly made physical sense. A new method for analyzing nonlinear and nonstationary data has been developed. The key part is the Empirical Mode Decomposition (EMD) method with which any complicated data set can be decomposed into a finite and often small number of Intrinsic Mode Functions (IMF) that serve as the basis of the representation of the data, This decomposition method is adaptive, and, therefore, highly efficient. The IMFs admit well-behaved Hilbert transforms, and yield instantaneous
Li, Yong; Fang, Hui; Min, Changjun; Yuan, Xiaocong
2015-01-01
Under the usual approximation of treating a biological particle as a spheroidal droplet, we consider the analysis of its size and shape with the high frequency photoacoustics and develop a numerical method which can simulate its characteristic photoacoustic waves. This numerical method is based on the calculation of spheroidal wave functions, and when comparing to the finite element model (FEM) calculation, can reveal more physical information and can provide results independently at each spatial points. As the demonstration, red blood cells (RBCs) and MCF7 cell nuclei are studied, and their photoacoustic responses including field distribution, spectral amplitude, and pulse forming are calculated. We expect that integrating this numerical method with the high frequency photoacoustic measurement will form a new modality being extra to the light scattering method, for fast assessing the morphology of a biological particle. PMID:26442830
Chameleon fields, wave function collapse and quantum gravity
NASA Astrophysics Data System (ADS)
Zanzi, A.
2015-07-01
Chameleon fields are quantum (usually scalar) fields, with a density-dependent mass. In a high-density environment, the mass of the chameleon is large. On the contrary, in a small-density environment (e.g. on cosmological distances), the chameleon is very light. A model where the collapse of the wave function is induced by chameleon fields is presented. During this analysis, a Chameleonic Equivalence Principle (CEP) will be formulated: in this model, quantum gravitation is equivalent to a conformal anomaly. Further research efforts are necessary to verify whether this proposal is compatible with phenomeno logical constraints.
Standard quantum mechanics featuring probabilities instead of wave functions
Manko, V. I. Manko, O. V.
2006-06-15
A new formulation of quantum mechanics (probability representation) is discussed. In this representation, a quantum state is described by a standard positive definite probability distribution (tomogram) rather than by a wave function. An unambiguous relation (analog of Radon transformation) between the density operator and a tomogram is constructed both for continuous coordinates and for spin variables. A novel feature of a state, tomographic entropy, is considered, and its connection with von Neumann entropy is discussed. A one-to-one map of quantum observables (Hermitian operators) on positive probability distributions is found.
Is spontaneous wave function collapse testable at all?
NASA Astrophysics Data System (ADS)
Diósi, Lajos
2015-07-01
Mainstream literature on spontaneous wave function collapse never reflects on or profits from the formal coincidence and conceptual relationship with standard collapse under time-continuous quantum measurement (monitoring). I propose some easy lessons of standard monitoring theory which would make spontaneous collapse models revise some of their claims. In particular, the objective detection of spontaneous collapse remains impossible as long as the correct identification of what corresponds to the signal in standard monitoring is missing from spontaneous collapse models, the physical detectability of the “signal” is not stated explicitly and, finally, the principles of physical detection are not revealed.
Average wave function method for gas-surface scattering
NASA Astrophysics Data System (ADS)
Singh, Harjinder; Dacol, Dalcio K.; Rabitz, Herschel
1986-02-01
The average wave function method (AWM) is applied to scattering of a gas off a solid surface. The formalism is developed for both periodic as well as disordered surfaces. For an ordered lattice an explicit relation is derived for the Bragg peaks along with a numerical illustration. Numerical results are presented for atomic clusters on a flat hard wall with a Gaussian-like potential at each atomic scattering site. The effect of relative lateral displacement of two clusters upon the scattering pattern is shown. The ability of AWM to accommodate disorder through statistical averaging over cluster configurations is illustrated. Enhanced uniform backscattering is observed with increasing roughness on the surface.
Numerical simulations of blast/shock wave propagations after nuclear explosions
NASA Astrophysics Data System (ADS)
Song, Seungho; Choi, Jung-Il; Li, Yibao; Lee, Changhoon
2013-11-01
Pressure waves develop immediately after nuclear explosions and start to move outward from the fireball. The most of initial damages are caused by the blast waves. We performed the blast wave propagations by solving two-dimensional and axisymmetric Euler equations. For shock capturing, inviscid fluxes are discretized using a variant of the piecewise parabolic method (PPM) and an approximate Riemann solver based on Roe's method is used. A clean air burst of fireball above the ground zero is considered. The initial condition of fireball is given at the point of breakaway that shock waves are appeared on the surface of the fireball. The growth of fireball is also calculated by solving one-dimensional radiation hydrodynamics (RHD) equation from point explosion. Characteristics of the blast wave propagations due to the various heights of burst and amount of the nuclear detonations are investigated. The results of parametric studies will be shown in the final presentation. Supported by Agency for Defense Development.
Horizon wave-function and the quantum cosmic censorship
NASA Astrophysics Data System (ADS)
Casadio, Roberto; Micu, Octavian; Stojkovic, Dejan
2015-07-01
We investigate the Cosmic Censorship Conjecture by means of the horizon wave-function (HWF) formalism. We consider a charged massive particle whose quantum mechanical state is represented by a spherically symmetric Gaussian wave-function, and restrict our attention to the superextremal case (with charge-to-mass ratio α > 1), which is the prototype of a naked singularity in the classical theory. We find that one can still obtain a normalisable HWF for α2 < 2, and this configuration has a non-vanishing probability of being a black hole, thus extending the classically allowed region for a charged black hole. However, the HWF is not normalisable for α2 > 2, and the uncertainty in the location of the horizon blows up at α2 = 2, signalling that such an object is no more well-defined. This perhaps implies that a quantum Cosmic Censorship might be conjectured by stating that no black holes with charge-to-mass ratio greater than a critical value (of the order of √{ 2}) can exist.
Wave functions for fractional Chern insulators in disk geometry
NASA Astrophysics Data System (ADS)
He, Ai-Lei; Luo, Wei-Wei; Wang, Yi-Fei; Gong, Chang-De
2015-12-01
Recently, fractional Chern insulators (FCIs), also called fractional quantum anomalous Hall (FQAH) states, have been theoretically established in lattice systems with topological flat bands. These systems exhibit similar fractionalization phenomena to the conventional fractional quantum Hall (FQH) systems. Using the mapping relationship between the FQH states and the FCI/FQAH states, we construct the many-body wave functions of the fermionic FCI/FQAH states in disk geometry with the aid of the generalized Pauli principle (GPP) and Jack polynomials. Compared with the ground state by the exact diagonalization method, the wave-function overlap is higher than 0.97, even when the Hilbert space dimension is as large as 3 × 106. We also use the GPP and the Jack polynomials to construct edge excitations for the fermionic FCI/FQAH states. The quasi-degeneracy sequences of fermionic FCI/FQAH systems reproduce the prediction of the chiral Luttinger liquid theory, complementing the exact diagonalization results with larger lattice sizes and more particles.
Dynamics of nuclear wave packets at the F center in alkali halides
NASA Astrophysics Data System (ADS)
Koyama, Takeshi; Suemoto, Tohru
2011-07-01
The F center in alkali halides is a well-known prototype of a strongly coupled localized electron-phonon system. This colour center is one of the long studied targets in the field of photophysics because it is simple but rich in variety. Steady-state spectroscopy, such as modulation spectroscopy and Raman scattering spectroscopy, has elucidated the strength of the electron-phonon coupling in the (meta-)stable state, i.e. the ground state and the relaxed excited state. Picosecond spectroscopy has improved understanding of the state mixing in the transient state. Owing to recent developments of ultrafast lasers with pulse widths shorter than oscillation periods of phonons, it has been possible to perform real-time observation of lattice vibration, and the understanding of the transient state has been remarkably expanded. In this paper, we review early and present studies on dynamics of electron-phonon coupling at the F center, especially recent real-time observations on the dynamics of nuclear wave packets in the excited state of the F center in KI, KBr, KCl and RbCl. These real-time observations reveal (i) spatial extension of the electronic wave function of a trapped electron, (ii) the difference between the coupled phonons in the ground state and the excited state, (iii) diabatic transition between the adiabatic potential energy surfaces and (iv) anharmonicity of the potential energy surface.
Puster, P.; Jordan, T.H.
1996-11-20
We apply methods for the recovery of the frequency dependent moment rate tensor, M(w), to the study of Lop Nor nuclear explosions. This approach encompasses many source parameter diagnostics that have been traditionally used to discriminate nuclear explosions from chemical explosions and earthquakes and has the potential to provide new discrimination tools. We parameterize the source as M(w) = M1(a) + MD(a), where M1(co) and MD(O) are isotropic and deviatoric components, respectively. Our goal is to quantify both isotropic and deviatoric components, and investigate the different contributions to MD(a), in particular the tectonic release. Since tectonic release can bias estimates of M1(o) and may limit discrimination capabilities of sparse networks, it is important to be able to characterize the amount of tectonic release - in particular as a function of frequency. Our approach uses synthetic seismograms to improve the localization of signal measurements in both time and frequency domains. We adapt our earthquake-source inversion algorithms to account for isotropic sources at very shallow depths. We test our algorithms using a synthetic case with a known moment-tensor source composed in equal parts of isotropic and deviatoric sources; we successfully recover both MD and M using body waves and surface waves on horizontal and vertical components. We apply our methods to a data set containing both SH and Love waves as well as the body-wave portion between P and R1 and the minor-arc Rayleigh waves from the 92/5/21 Chinese nuclear test. We recover a significant tectonic release component for this event; the deviatoric moment tensor is a dip-slip reverse fault with a scalar moment MD = 1.9 +/- 0.2 x 10(17) Nm. The strike of the best-fitting double-couple is 320 deg. The source-time function derived from SH-polarized waves shows some complexity, with a sharp pulse i.
Goal direction and effectiveness, emotional maturity, and nuclear family functioning.
Klever, Phillip
2009-07-01
Differentiation of self, a cornerstone concept in Bowen theory, has a profound influence over time on the functioning of the individual and his or her family unit. This 5-year longitudinal study tested this hypothesis with 50 developing nuclear families. The dimensions of differentiation of self that were examined were goal direction and effectiveness and emotional maturity. A qualitative analysis of participants' goals demonstrated that couples with higher functioning developing nuclear families, when compared with couples with lower functioning families, placed more emphasis on family goals, had more balance between family and personal goals, and pursued more goals over the 5 years. The quantitative analysis supported the hypothesis that goal effectiveness and emotional maturity influenced variation in nuclear family functioning. In addition, couple goal effectiveness and emotional maturity were associated with nuclear family functioning more strongly than individual goal effectiveness and emotional maturity were associated with individual functioning. PMID:19522784
Quantification of Uncertainties in Nuclear Density Functional Theory
Schunck, N.; McDonnell, J.D.; Higdon, D.; Sarich, J.; Wild, S.
2015-01-15
Reliable predictions of nuclear properties are needed as much to answer fundamental science questions as in applications such as reactor physics or data evaluation. Nuclear density functional theory is currently the only microscopic, global approach to nuclear structure that is applicable throughout the nuclear chart. In the past few years, a lot of effort has been devoted to setting up a general methodology to assess theoretical uncertainties in nuclear DFT calculations. In this paper, we summarize some of the recent progress in this direction. Most of the new material discussed here will be be published in separate articles.
Magnetospheric electron-velocity-distribution function information from wave observations
NASA Astrophysics Data System (ADS)
Benson, Robert F.; ViñAs, Adolfo F.; Osherovich, Vladimir A.; Fainberg, Joseph; Purser, Carola M.; Adrian, Mark L.; Galkin, Ivan A.; Reinisch, Bodo W.
2013-08-01
The electron-velocity-distribution function was determined to be highly non-Maxwellian and more appropriate to a kappa distribution, with κ ≈ 2.0, near magnetic midnight in the low-latitude magnetosphere just outside a stable plasmasphere during extremely quiet geomagnetic conditions. The kappa results were based on sounder-stimulated Qn plasma resonances using the Radio Plasma Imager (RPI) on the IMAGE satellite; the state of the plasmasphere was determined from IMAGE/EUV observations. The Qn resonances correspond to the maximum frequencies of Bernstein-mode waves that are observed between the harmonics of the electron cyclotron frequency in the frequency domain above the upper-hybrid frequency. Here we present the results of a parametric investigation that included suprathermal electrons in the electron-velocity-distribution function used in the plasma-wave dispersion equation to calculate the Qn frequencies for a range of kappa and fpe/fce values for Qn resonances from Q1 to Q9. The Qn frequencies were also calculated using a Maxwellian distribution, and they were found to be greater than those calculated using a kappa distribution with the frequency differences increasing with increasing n for a fixed κ and with decreasing κ for a fixed n. The calculated fQn values have been incorporated into the RPI BinBrowser software providing a powerful tool for rapidly obtaining information on the nature of the magnetospheric electron-velocity-distribution function and the electron number density Ne. This capability enabled accurate (within a few percent) in situ Ne determinations to be made along the outbound orbital track as IMAGE moved away from the plasmapause. The extremely quiet geomagnetic conditions allowed IMAGE/EUV-extracted counts to be compared with the RPI-determined orbital-track Ne profile. The comparisons revealed remarkably similar Ne structures.
Magnetospheric Electron-Velocity-Distribution Function Information from Wave Observations
NASA Astrophysics Data System (ADS)
Benson, R. F.; Vinas, A. F.; Osherovich, V. A.; Fainberg, J.; Purser, C. M.; Adrian, M. L.; Galkin, I. A.; Reinisch, B. W.
2013-12-01
The electron-velocity-distribution function was determined to be highly non-Maxwellian and more appropriate to a kappa distribution, with κ ≈ 2.0, near magnetic midnight in the low-latitude magnetosphere just outside a stable plasmasphere during extremely quiet geomagnetic conditions. The kappa results were based on sounder-stimulated Qn plasma resonances using the Radio Plasma Imager (RPI) on the IMAGE satellite; the state of the plasmasphere was determined from IMAGE/EUV observations. The Qn resonances correspond to the maximum frequencies of Bernstein-mode waves that are observed between the harmonics of the electron cyclotron frequency in the frequency domain above the upper-hybrid frequency. Here we present the results of a parametric investigation that included suprathermal electrons in the electron-velocity-distribution function used in the plasma-wave dispersion equation to calculate the Qn frequencies for a range of kappa and fpe/fce values for Qn resonances from Q1 to Q9. The Qn frequencies were also calculated using a Maxwellian distribution and they were found to be greater than those calculated using a kappa distribution with the frequency differences increasing with increasing n for a fixed κ and with decreasing κ for a fixed n. The calculated fQn values have been incorporated into the RPI BinBrowser software providing a powerful tool for rapidly obtaining information on the nature of the magnetospheric electron-velocity-distribution function and the electron number density Ne. This capability enabled accurate (within a few percent) in-situ Ne determinations to be made along the outbound orbital track as IMAGE moved away from the plasmapause. The extremely quiet geomagnetic conditions allowed IMAGE/EUV-extracted counts to be compared with the RPI-determined orbital-track Ne profile. The comparisons revealed remarkably similar Ne structures.
Nuclear reactions in shock wave front during supernova events
NASA Technical Reports Server (NTRS)
Lavrukhina, A. K.
1985-01-01
The new unique isotopic anomalous coponent of Xe(XeX) was found in the carbonaceous chondrites. It is enriched in light shielded isotopes (124Xe and 126Xe) and in heavy nonshielded isotopes (134Xe and 136Xe. All characteristics of Xe-X can be explained by a model of nucleosynthesis of the Xe isotopes in shock wave front passed through the He envelope during supernova events. The light isotopes are created by p process and the heavy isotopes are created by n process (slow r process). They were captured with high temperature carbon grains condensing by supernova shock waves.
NASA Astrophysics Data System (ADS)
Sokolova, Inna
2015-04-01
Availability of the acoustic wave on the record of microbarograph is one of discriminate signs of atmospheric (surface layer of atmosphere) and contact explosions. Nowadays there is large number of air wave records from chemical explosions recorded by the IMS infrasound stations installed during recent decade. But there is small number of air wave records from nuclear explosions as air and contact nuclear explosions had been conducted since 1945 to 1962, before the Limited Test Ban Treaty was signed in 1963 (the treaty banning nuclear weapon tests in the atmosphere, in outer space and under water) by the Great Britain, USSR and USA. That time there was small number of installed microbarographs. First infrasound stations in the USSR appeared in 1954, and by the moment of the USSR collapse the network consisted of 25 infrasound stations, 3 of which were located on Kazakhstan territory - in Kurchatov (East Kazakhstan), in Borovoye Observatory (North Kazakhstan) and Talgar Observatory (Northern Tien Shan). The microbarograph of Talgar Observatory was installed in 1962 and recorded large number of air nuclear explosions conducted at Semipalatinsk Test Site and Novaya Zemlya Test Site. The epicentral distance to the STS was ~700 km, and to Novaya Zemlya Test Site ~3500 km. The historical analog records of the microbarograph were analyzed on the availability of the acoustic wave. The selected records were digitized, the database of acoustic signals from nuclear explosions was created. In addition, acoustic signals from atmospheric nuclear explosions conducted at the USSR Test Sites were recorded by analogue broadband seismic stations at wide range of epicentral distances, 300-3600 km. These signals coincide well by its form and spectral content with records of microbarographs and can be used for monitoring tasks and discrimination in places where infrasound observations are absent. Nuclear explosions which records contained acoustic wave were from 0.03 to 30 kt yield for
Nuclear collective excitations: A relativistic density functional approach
NASA Astrophysics Data System (ADS)
Piekarewicz, J.
2015-08-01
Density functional theory provides the most promising, and likely unique, microscopic framework to describe nuclear systems ranging from finite nuclei to neutron stars. Properly optimized energy density functionals define a new paradigm in nuclear theory where predictive capability is possible and uncertainty quantification is demanded. Moreover, density functional theory offers a consistent approach to the linear response of the nuclear ground state. In this paper, we review the fundamental role played by nuclear collective modes in uncovering novel excitations and in guiding the optimization of the density functional. Indeed, without collective excitations the determination of the density functional remains incomplete. Without collective excitations, the equation of state of neutron-rich matter continues to be poorly constrained. We conclude with a discussion of some of the remaining challenges in this field and propose a path forward to address these challenges.
Tissue specificity in the nuclear envelope supports its functional complexity
de las Heras, Jose I; Meinke, Peter; Batrakou, Dzmitry G; Srsen, Vlastimil; Zuleger, Nikolaj; Kerr, Alastair RW; Schirmer, Eric C
2013-01-01
Nuclear envelope links to inherited disease gave the conundrum of how mutations in near-ubiquitous proteins can yield many distinct pathologies, each focused in different tissues. One conundrum-resolving hypothesis is that tissue-specific partner proteins mediate these pathologies. Such partner proteins may have now been identified with recent proteome studies determining nuclear envelope composition in different tissues. These studies revealed that the majority of the total nuclear envelope proteins are tissue restricted in their expression. Moreover, functions have been found for a number these tissue-restricted nuclear envelope proteins that fit with mechanisms proposed to explain how the nuclear envelope could mediate disease, including defects in mechanical stability, cell cycle regulation, signaling, genome organization, gene expression, nucleocytoplasmic transport, and differentiation. The wide range of functions to which these proteins contribute is consistent with not only their involvement in tissue-specific nuclear envelope disease pathologies, but also tissue evolution. PMID:24213376
Semiclassical-wave-function perspective on high-harmonic generation
NASA Astrophysics Data System (ADS)
Mauger, François; Abanador, Paul M.; Lopata, Kenneth; Schafer, Kenneth J.; Gaarde, Mette B.
2016-04-01
We introduce a semiclassical-wave-function (SCWF) model for strong-field physics and attosecond science. When applied to high-harmonic generation (HHG), this formalism allows one to show that the natural time-domain separation of the contribution of ionization, propagation, and recollisions to the HHG process leads to a frequency-domain factorization of the harmonic yield into these same contributions, for any choice of atomic or molecular potential. We first derive the factorization from the natural expression of the dipole signal in the temporal domain by using a reference system, as in the quantitative rescattering (QRS) formalism [J. Phys. B 43, 122001 (2010), 10.1088/0953-4075/43/12/122001]. Alternatively, we show how the trajectory component of the SCWF can be used to express the factorization, which also allows one to attribute individual contributions to the spectrum to the underlying trajectories.
Human brain networks function in connectome-specific harmonic waves
Atasoy, Selen; Donnelly, Isaac; Pearson, Joel
2016-01-01
A key characteristic of human brain activity is coherent, spatially distributed oscillations forming behaviour-dependent brain networks. However, a fundamental principle underlying these networks remains unknown. Here we report that functional networks of the human brain are predicted by harmonic patterns, ubiquitous throughout nature, steered by the anatomy of the human cerebral cortex, the human connectome. We introduce a new technique extending the Fourier basis to the human connectome. In this new frequency-specific representation of cortical activity, that we call ‘connectome harmonics', oscillatory networks of the human brain at rest match harmonic wave patterns of certain frequencies. We demonstrate a neural mechanism behind the self-organization of connectome harmonics with a continuous neural field model of excitatory–inhibitory interactions on the connectome. Remarkably, the critical relation between the neural field patterns and the delicate excitation–inhibition balance fits the neurophysiological changes observed during the loss and recovery of consciousness. PMID:26792267
Source function and plane waves: Toward complete bader analysis.
Tantardini, Christian; Ceresoli, Davide; Benassi, Enrico
2016-09-01
The source function (SF) is a topological descriptor that was introduced and developed by C. Gatti and R.W. Bader in 1998. The SF describes the contribution of each atom to the total electron density at a given point. To date, this descriptor has only been calculable from electron densities generated by all-electron (AE) methods for the investigation of single molecules or periodic systems. This study broadens the accessibility of the SF, offering its calculation from electron densities generated by plane wave (PW) methods. The new algorithm has been implemented in the open source code, CRITIC2. Our novel approach has been validated on a series of test systems, comparing the results obtained at PW level with those previously obtained through AE methods. © 2016 Wiley Periodicals, Inc. PMID:27364862
NASA Astrophysics Data System (ADS)
Hong, T.-K.
2009-04-01
Understanding the shear-wave excitation mechanism is a key issue for effective seismic monitoring of underground nuclear explosions (UNEs). We often observe strong shear waves from UNEs, which causes difficulty in prompt discrimination of nuclear explosions from natural earthquakes. Various mechanisms have been proposed to explain the shear-wave excitation from the UNEs. Consensus on dominant mechanism of shear-wave excitation has not been made. To constrain the shear-wave excitation mechanism, we examine the consistency in shear-wave radiation pattern using a source-array slowness-wavenumber (F-K) analysis, which allows us to check the time-invariant feature in the shear waves. We examine regional and teleseismic waveforms for the UNEs of the Balapan test site and Nevada test site along with the Indian and North Korean UNEs. We observe consistent radiation pattern in both regional and teleseismic shear waves. The observed radiation pattern suggests that the shear waves were not excited azimuthally-isotropic. Shear waves observed in teleseismic distances are far weak compared to those in regional distances, which implies that shear waves are excited stronger at high takeoff angles. Also, spectra of shear waves display significantly low overshoot feature that is different from those of P phases. The time-invariant anisotropic radiation pattern, strong excitation in high takeoff angle and low overshoot feature allow us to constrain the shear-wave excitation mechanism.
Impact of permeability on seismoelectric transfer function of P waves
NASA Astrophysics Data System (ADS)
Holzhauer, J.; Bordes, C.; Oppermann, F.; Brito, D.; Yaramanci, U.
2012-04-01
Recent developments in the understanding of seismoelectrics have shown its potential relevance for porous media characterization with particular focus on permeability estimations. According to promising theoretical and numerical studies, permeability should influence the seismoelectric transfer function at higher frequencies. The dynamic seismoelectric transfer function E(ω)/ ü(ω), where E relates to the coseismic electric field induced by the seismic particle acceleration ü, is expected to increase with increasing permeabilities when crossing the Biot transition frequency. Still, only few experiments have been developed on that matter so far. To address the transfer function dependence on permeability, we adapted a column experiment to comply with steady-state permeability estimations. These observations were run in-situ, during the fluid-balancing phase prior to seismoelectric measurements. The 50 cm-long column had previously been carefully filled with perfectly rounded glass beads. The use of sorted glass beads is expected to achieve similar porosities reproducible throughout the experiment, opposed to varying permeabilities depending on the introduced particle size. The acoustic source delivered compressional waves with an optimal effect limited to the [1-3] kHz frequency range. These limitations are due to strong seismic attenuation in uncompacted porous media on one side, and to the dilemma of observing propagation in downsized laboratory setup on the other. First results validated the experimental protocol in terms of porosity/permeability independence: for particle size varying between 100 μm and 500 μm, permeability varied by a factor 20, with a maximum by 5.10-11 m2, while porosity remained by 39 ± 2 % during the whole experiment. Further investigations are being led regarding the normalised transfer function, corrected for both the fluid conductivity and the seismic energy. For that purpose, we compare the dependence of our measured transfer
Study on far field wave patterns and their characteristics of Havelock form green function
NASA Astrophysics Data System (ADS)
Xu, Yong; Dong, Wen-cai; Xiao, Wen-bin
2013-06-01
A new mathematical integral representation including five integrals about the far field wave shape function of Havelock form translating-pulsating source is obtained by performing variable substitution. Constant-phase curves and propagation wave patterns are investigated by applying stationary phase analysis method to the new representation. Some findings are summarized as follows: (1) when 0< τ <0.25 (where τ is the Strouhal number), three types of stationary phase curves corresponding to three propagation wave patterns such as fan wave pattern, inner V and outer V wave patterns, are found in the integral representation. (2) When τ>0.25, besides three types of wave patterns such as a ring-faning wave pattern, a fan wave pattern and an inner V wave pattern, a new one called parallel wave pattern is also found which not only exists in the integrals about the ring-fan wave and fan wave, but also in the integrals whose interval is [0, γ] In addition, Characteristics about these parallel waves such as mathematical expressions, existence conditions, propagation directions and wave lengths are obtained, and cancellation relationships between these parallel waves are stated, which certificates the fact that there are no parallel waves existing in the far field.
Bohmian Conditional Wave Functions (and the status of the quantum state)
NASA Astrophysics Data System (ADS)
Norsen, Travis
2016-03-01
The de Broglie - Bohm pilot-wave theory - uniquely among realistic candidate quantum theories - allows a straightforward and simple definition of the wave function of a subsystem of some larger system (such as the entire universe). Such sub-system wave functions are called “Conditional Wave Functions” (CWFs). Here we explain this concept and indicate the CWF's role in the Bohmian explanation of the usual quantum formalism, and then develop (and motivate) the more speculative idea that something like single-particle wave functions could replace the (ontologically problematical) universal wave function in some future, empirically adequate, pilot-wave-type theory. Throughout the presentation is pedagogical and points are illustrated with simple toy models.
Nonlocal density-functional description constructed from a correlated many-body wave function
NASA Astrophysics Data System (ADS)
Umezawa, Naoto; Tsuneyuki, Shinji
2004-03-01
We suggest a new approach to the nonlocal density-functional theory. In our method, the nonlocal correlation functional is derived from a correlated many-body wave function using the transcorrelated similarity transformation [1,2]. Our formalism is rigorous in principle if the v-representable density is assumed. In practice, Jastrow-Slater-type wave function is adopted and the correlation functional consists of many-body interactions originated from the Jastrow factor. Instead of struggling with these higher order interactions, we retain only 2-body interactions multiplying an adjusting parameter so that it can reproduce the exact correlation energy for the homogeneous electron gas. Therefore, the computational cost is comparable to the exact exchange method. Moreover, parameters in the Jastrow factor are determined by the two conditions: the cusp conditions and the random-phase approximation without empirical fitting. We found that our correlation functional gives fairly good results for small atoms and ions (He, Li^+, Be^2+, Li, and Be). [1]S. F. Boys and N. C. Handy, Proc. Roy. Soc. A, 309, 209; 310, 43; 310, 63; 311, 309. [2] N. Umezawa and S. Tsuneyuki, J. Chem. Phys. 119, 10015 (2003).
Variational Approach to Yang-Mills Theory with non-Gaussian Wave Functionals
NASA Astrophysics Data System (ADS)
Campagnari, Davide R.; Reinhardt, Hugo
2011-05-01
A general method for treating non-Gaussian wave functionals in quantum field theory is presented and applied to the Hamiltonian approach to Yang-Mills theory in Coulomb gauge in order to include a three-gluon kernel in the exponential of the vacuum wave functional. The three-gluon vertex is calculated using the propagators found in the variational approach with a Gaussian trial wave functional as input.
Riemann {zeta} function from wave-packet dynamics
Mack, R.; Schleich, W. P.; Dahl, J. P.; Moya-Cessa, H.; Strunz, W. T.; Walser, R.
2010-09-15
We show that the time evolution of a thermal phase state of an anharmonic oscillator with logarithmic energy spectrum is intimately connected to the generalized Riemann {zeta} function {zeta}(s,a). Indeed, the autocorrelation function at a time t is determined by {zeta}({sigma}+i{tau},a), where {sigma} is governed by the temperature of the thermal phase state and {tau} is proportional to t. We use the JWKB method to solve the inverse spectral problem for a general logarithmic energy spectrum; that is, we determine a family of potentials giving rise to such a spectrum. For large distances, all potentials display a universal behavior; they take the shape of a logarithm. However, their form close to the origin depends on the value of the Hurwitz parameter a in {zeta}(s,a). In particular, we establish a connection between the value of the potential energy at its minimum, the Hurwitz parameter and the Maslov index of JWKB. We compare and contrast exact and approximate eigenvalues of purely logarithmic potentials. Moreover, we use a numerical method to find a potential which leads to exact logarithmic eigenvalues. We discuss possible realizations of Riemann {zeta} wave-packet dynamics using cold atoms in appropriately tailored light fields.
Assessing the orbital selective Mott transition with variational wave functions
NASA Astrophysics Data System (ADS)
Tocchio, Luca F.; Arrigoni, Federico; Sorella, Sandro; Becca, Federico
2016-03-01
We study the Mott metal-insulator transition in the two-band Hubbard model with different hopping amplitudes t 1 and t 2 for the two orbitals on the two-dimensional square lattice by using non-magnetic variational wave functions, similarly to what has been considered in the limit of infinite dimensions by dynamical mean-field theory. We work out the phase diagram at half filling (i.e. two electrons per site) as a function of R={{t}2}/{{t}1} and the on-site Coulomb repulsion U, for two values of the Hund’s coupling J = 0 and J/U = 0.1. Our results are in good agreement with previous dynamical mean-field theory calculations, demonstrating that the non-magnetic phase diagram is only slightly modified from infinite to two spatial dimensions. Three phases are present: a metallic one, for small values of U, where both orbitals are itinerant; a Mott insulator, for large values of U, where both orbitals are localized because of the Coulomb repulsion; and the so-called orbital-selective Mott insulator (OSMI), for small values of R and intermediate Us, where one orbital is localized while the other one is still itinerant. The effect of the Hund’s coupling is two-fold: on one side, it favors the full Mott phase over the OSMI; on the other side, it stabilizes the OSMI at larger values of R.
Wave function for time-dependent harmonically confined electrons in a time-dependent electric field.
Li, Yu-Qi; Pan, Xiao-Yin; Sahni, Viraht
2013-09-21
The many-body wave function of a system of interacting particles confined by a time-dependent harmonic potential and perturbed by a time-dependent spatially homogeneous electric field is derived via the Feynman path-integral method. The wave function is comprised of a phase factor times the solution to the unperturbed time-dependent Schrödinger equation with the latter being translated by a time-dependent value that satisfies the classical driven equation of motion. The wave function reduces to that of the Harmonic Potential Theorem wave function for the case of the time-independent harmonic confining potential. PMID:24070284
NASA Astrophysics Data System (ADS)
Ritboon, Atirach; Daengngam, Chalongrat; Pengpan, Teparksorn
2016-08-01
Biakynicki-Birula introduced a photon wave function similar to the matter wave function that satisfies the Schrödinger equation. Its second quantization form can be applied to investigate nonlinear optics at nearly full quantum level. In this paper, we applied the photon wave function formalism to analyze both linear optical processes in the well-known Mach-Zehnder interferometer and nonlinear optical processes for sum-frequency generation in dispersive and lossless medium. Results by photon wave function formalism agree with the well-established Maxwell treatments and existing experimental verifications.
Decommissioning nuclear power plants - the wave of the future
Griggs, F.S. Jr.
1994-12-31
The paper discusses the project controls developed in the decommissioning of a nuclear power plant. Considerations are given to the contaminated piping and equipment that have to be removed and the spent and used fuel that has to be disposed of. The storage issue is of primary concern here. The cost control aspects and the dynamics of decommissioning are discussed. The effects of decommissioning laws on the construction and engineering firms are mentioned. 5 refs.
THz-waves channeling in a monolithic saddle-coil for Dynamic Nuclear Polarization enhanced NMR
NASA Astrophysics Data System (ADS)
Macor, A.; de Rijk, E.; Annino, G.; Alberti, S.; Ansermet, J.-Ph.
2011-10-01
A saddle coil manufactured by electric discharge machining (EDM) from a solid piece of copper has recently been realized at EPFL for Dynamic Nuclear Polarization enhanced Nuclear Magnetic Resonance experiments (DNP-NMR) at 9.4 T. The corresponding electromagnetic behavior of radio-frequency (400 MHz) and THz (263 GHz) waves were studied by numerical simulation in various measurement configurations. Moreover, we present an experimental method by which the results of the THz-wave numerical modeling are validated. On the basis of the good agreement between numerical and experimental results, we conducted by numerical simulation a systematic analysis on the influence of the coil geometry and of the sample properties on the THz-wave field, which is crucial in view of the optimization of DNP-NMR in solids.
THz-waves channeling in a monolithic saddle-coil for Dynamic Nuclear Polarization enhanced NMR.
Macor, A; de Rijk, E; Annino, G; Alberti, S; Ansermet, J-Ph
2011-10-01
A saddle coil manufactured by electric discharge machining (EDM) from a solid piece of copper has recently been realized at EPFL for Dynamic Nuclear Polarization enhanced Nuclear Magnetic Resonance experiments (DNP-NMR) at 9.4 T. The corresponding electromagnetic behavior of radio-frequency (400 MHz) and THz (263 GHz) waves were studied by numerical simulation in various measurement configurations. Moreover, we present an experimental method by which the results of the THz-wave numerical modeling are validated. On the basis of the good agreement between numerical and experimental results, we conducted by numerical simulation a systematic analysis on the influence of the coil geometry and of the sample properties on the THz-wave field, which is crucial in view of the optimization of DNP-NMR in solids. PMID:21903436
Oscarsson, T.E.; Roennmark, K.G. )
1990-12-01
In this paper the authors present an investigation of low-frequency waves observed on auroral field lines below the acceleration region by the Swedish satellite Viking. The measured frequency spectra are peaked at half the local proton gyrofrequency, and the waves are observed in close connection with precipitating electrons. In order to obtain information about the distribution of wave energy in wave vector space, they reconstruct the wave distribution function (WDF) from observed spectral densities. They use a new scheme that allows them to reconstruct simultaneously the WDF over a broad frequency band. The method also makes it possible to take into account available particle observations as well as Doppler shifts caused by the relative motion between the plasma and the satellite. The distribution of energy in wave vector space suggested by the reconstructed WDF is found to be consistent with what is expected from a plasma instability driven by the observed precipitating electrons. Furthermore, by using UV images obtained on Viking, they demonstrate that the wave propagation directions indicated by the reconstructed WDFs are consistent with a simple model of the presumed wave source in the electron precipitation region.
Bischoff, Florian A; Harrison, Robert J; Valeev, Edward F
2012-09-14
We present an approach to compute accurate correlation energies for atoms and molecules using an adaptive discontinuous spectral-element multiresolution representation for the two-electron wave function. Because of the exponential storage complexity of the spectral-element representation with the number of dimensions, a brute-force computation of two-electron (six-dimensional) wave functions with high precision was not practical. To overcome the key storage bottlenecks we utilized (1) a low-rank tensor approximation (specifically, the singular value decomposition) to compress the wave function, and (2) explicitly correlated R12-type terms in the wave function to regularize the Coulomb electron-electron singularities of the Hamiltonian. All operations necessary to solve the Schrödinger equation were expressed so that the reconstruction of the full-rank form of the wave function is never necessary. Numerical performance of the method was highlighted by computing the first-order Møller-Plesset wave function of a helium atom. The computed second-order Møller-Plesset energy is precise to ~2 microhartrees, which is at the precision limit of the existing general atomic-orbital-based approaches. Our approach does not assume special geometric symmetries, hence application to molecules is straightforward. PMID:22979846
NASA Astrophysics Data System (ADS)
López-Rosa, S.; Esquivel, R. O.; Plastino, A. R.; Dehesa, J. S.
2015-09-01
In this work we have performed state-of-the-art configuration-interaction (CI) calculations to determine the linear and von Neumann entanglement entropies for the helium-like systems with varying nuclear charge Z in the range 1≤slant Z≤slant 10. The focus of the work resides on determining accurate entanglement values for 2-electron systems with the lowest computational cost through compact CI-wave functions. Our entanglement results for the helium atom fully agree with the results obtained with higher quality wave functions of the Kinoshita type (Dehesa [5]). We find that the correlation energy is linearly related to the entanglement measures associated with the linear and von Neumann entropies of the single-particle reduced density matrizes, which sheds new light on the physical implications of entanglement in helium-like systems. Moreover, we report CI-wave-function-based benchmark results for the entanglement values for all members of the helium isoelectronic series with an accuracy similar to that of Kinoshita-type wave functions. Finally, we give parametric expressions of the linear and von Neumann entanglement measures for two-electron systems as Z varies from 1 to 10.
Exact density functional and wave function embedding schemes based on orbital localization
NASA Astrophysics Data System (ADS)
Hégely, Bence; Nagy, Péter R.; Ferenczy, György G.; Kállay, Mihály
2016-08-01
Exact schemes for the embedding of density functional theory (DFT) and wave function theory (WFT) methods into lower-level DFT or WFT approaches are introduced utilizing orbital localization. First, a simple modification of the projector-based embedding scheme of Manby and co-workers [J. Chem. Phys. 140, 18A507 (2014)] is proposed. We also use localized orbitals to partition the system, but instead of augmenting the Fock operator with a somewhat arbitrary level-shift projector we solve the Huzinaga-equation, which strictly enforces the Pauli exclusion principle. Second, the embedding of WFT methods in local correlation approaches is studied. Since the latter methods split up the system into local domains, very simple embedding theories can be defined if the domains of the active subsystem and the environment are treated at a different level. The considered embedding schemes are benchmarked for reaction energies and compared to quantum mechanics (QM)/molecular mechanics (MM) and vacuum embedding. We conclude that for DFT-in-DFT embedding, the Huzinaga-equation-based scheme is more efficient than the other approaches, but QM/MM or even simple vacuum embedding is still competitive in particular cases. Concerning the embedding of wave function methods, the clear winner is the embedding of WFT into low-level local correlation approaches, and WFT-in-DFT embedding can only be more advantageous if a non-hybrid density functional is employed.
The Surface Wave Magnitude for the 9 October 2006 North Korean Nuclear Explosion
Bonner, J; Herrmann, R; Harkrider, D; Pasyanos, M
2008-03-11
Surface waves were generated by the North Korean nuclear explosion of 9 October 2006 and recorded at epicentral distances up to 34 degrees, from which we estimated a surface wave magnitude (M{sub s}) of 2.94 with an interstation standard deviation of 0.17 magnitude units. The International Data Centre estimated a body wave magnitude (m{sub b}) of 4.1. This is the only explosion we have analyzed that was not easily screened as an explosion based on the differences between the M{sub s} and m{sub b} estimates. Additionally, this M{sub s} predicts a yield, based on empirical M{sub s}/Yield relationships, that is almost an order of magnitude larger then the 0.5 to 1 kiloton reported for this explosion. We investigate how emplacement medium effects on surface wave moment and magnitude may have contributed to the yield discrepancy.
Newton force from wave function collapse: speculation and test
NASA Astrophysics Data System (ADS)
Diósi, Lajos
2014-04-01
The Diosi-Penrose model of quantum-classical boundary postulates gravity-related spontaneous wave function collapse of massive degrees of freedom. The decoherence effects of the collapses are in principle detectable if not masked by the overwhelming environmental decoherence. But the DP (or any other, like GRW, CSL) spontaneous collapses are not detectable themselves, they are merely the redundant formalism of spontaneous decoherence. To let DP collapses become testable physics, recently we extended the DP model and proposed that DP collapses are responsible for the emergence of the Newton gravitational force between massive objects. We identified the collapse rate, possibly of the order of 1/ms, with the rate of emergence of the Newton force. A simple heuristic emergence (delay) time was added to the Newton law of gravity. This non-relativistic delay is in peaceful coexistence with Einstein's relativistic theory of gravitation, at least no experimental evidence has so far surfaced against it. We derive new predictions of such a 'lazy' Newton law that will enable decisive laboratory tests with available technologies. The simple equation of 'lazy' Newton law deserves theoretical and experimental studies in itself, independently of the underlying quantum foundational considerations.
Inside looking out: Probing JIMWLK wave functions with BFKL calculations
Altinoluk, Tolga; Kovner, Alex; Levin, Eugene
2010-10-01
We investigate the relation between the eigenvalues and eigenfunctions of the Balitsky-Fadin-Kuraev-Lipatov (BFKL) and Jalilian-Marian-Iancu-McLerran-Weigert-Leonidov-Kovner (JIMWLK/KLWMIJ) Hamiltonians. We show that the eigenvalues of the BFKL Hamiltonians are also exact eigenvalues of the KLWMIJ (and JIMWLK) Hamiltonian, albeit corresponding to possibly non-normalizable eigenfunctions. The question whether a given eigenfunction of BFKL corresponds to a normalizable eigenfunction of KLWMIJ is rather complicated, except in some obvious cases, and requires independent investigation. As an example to illustrate this relation we concentrate on the color octet exchange in the framework of KLWMIJ Hamiltonian. We show that it corresponds to the reggeized gluon exchange of BFKL, and find first correction to the BFKL wave function, which has the meaning of the impact factor for shadowing correction to the Reggeized gluon. We also show that the bootstrap condition in the KLWMIJ framework is satisfied automatically and does not carry any additional information to that contained in the second quantized structure of the KLWMIJ Hamiltonian. This is an example of how the bootstrap condition inherent in the t-channel unitarity arises in the s-channel picture.
Spin constraints on nuclear energy density functionals
NASA Astrophysics Data System (ADS)
Robledo, L. M.; Bernard, R. N.; Bertsch, G. F.
2014-02-01
The Gallagher-Moszkowski rule in the spectroscopy of odd-odd nuclei imposes a new spin constraint on the energy functionals for self-consistent mean field theory. The commonly used parametrization of the effective three-body interaction in the Gogny and Skyrme families of energy functionals is ill suited to satisfy the spin constraint. In particular, the Gogny parametrization of the three-body interaction has the spin dependence opposite to that required by the observed spectra. The two-body part has a correct sign, but in combination the rule is violated as often as not. We conclude that a new functional form is needed for the effective three-body interaction that can take into better account the different spin-isospin channels of the interaction.
New Generation Nuclear Plant -- High Level Functions and Requirements
J. M. Ryskamp; E. J. Gorski; E. A. Harvego; S. T. Khericha; G. A. Beitel
2003-09-01
This functions and requirements (F&R) document was prepared for the Next Generation Nuclear Plant (NGNP) Project. The highest-level functions and requirements for the NGNP preconceptual design are identified in this document, which establishes performance definitions for what the NGNP will achieve. NGNP designs will be developed based on these requirements by commercial vendor(s).
US Nuclear Regulatory Commission organization charts and functional statements
1997-11-01
This document contains organization charts for the U.S. Nuclear Regulatory Commission (NRC) and for the five offices of the NRC. Function statements are provided delineating the major responsibilities and operations of each office. Organization and function are provided to the branch level. The head of each office, division, and branch is also listed.
Covariant nucleon wave function with S, D, and P-state components
Franz Gross, G. Ramalho, M. T. Pena
2012-05-01
Expressions for the nucleon wave functions in the covariant spectator theory (CST) are derived. The nucleon is described as a system with a off-mass-shell constituent quark, free to interact with an external probe, and two spectator constituent quarks on their mass shell. Integrating over the internal momentum of the on-mass-shell quark pair allows us to derive an effective nucleon wave function that can be written only in terms of the quark and diquark (quark-pair) variables. The derived nucleon wave function includes contributions from S, P and D-waves.
Attosecond photoemission dynamics encoded in real-valued continuum wave functions
NASA Astrophysics Data System (ADS)
Gaillac, Romain; Vacher, Morgane; Maquet, Alfred; Taïeb, Richard; Caillat, Jérémie
2016-01-01
The dynamics of photoemission is fully encoded in the continuum wave functions selected by the transitions. Using numerical simulations on simple benchmark models, we show how scattering phase shifts and photoemission delays can be retrieved from this unambiguously defined class of wave functions. In contrast with standard scattering waves inherited from collision theory, they are real-valued for one-photon transitions and provide a clear-cut interpretation of the delays recently discussed in the framework of attosecond science.
Hairless is a nuclear receptor corepressor essential for skin function
Thompson, Catherine C.
2009-01-01
The activity of nuclear receptors is modulated by numerous coregulatory factors. Corepressors can either mediate the ability of nuclear receptors to repress transcription, or can inhibit transactivation by nuclear receptors. As we learn more about the mechanisms of transcriptional repression, the importance of repression by nuclear receptors in development and disease has become clear. The protein encoded by the mammalian Hairless (Hr) gene was shown to be a corepressor by virtue of its functional similarity to the well-established corepressors N-CoR and SMRT. Mutation of the Hr gene results in congenital hair loss in both mice and men. Investigation of Hairless function both in vitro and in mouse models in vivo has revealed a critical role in maintaining skin and hair by regulating the differentiation of epithelial stem cells, as well as a putative role in regulating gene expression via chromatin remodeling. PMID:20087431
Irregular wave functions of a hydrogen atom in a uniform magnetic field
Wintgen, D. Max-Planck-Institut fuer Kernphysik, Postfach 103980, D-6900 Heidelberg, ); Honig, A. )
1989-10-02
We study the irregular wave functions of a highly excited hydrogen atom in a uniform magnetic field. The scarring of wave functions by periodic orbits is quantitatively investigated. The shape of unperturbed scars is in good agreement with recent semiclassical predictions.
NASA Astrophysics Data System (ADS)
Múnera, Héctor A.
2016-07-01
It is postulated that there exists a fundamental energy-like fluid, which occupies the flat three-dimensional Euclidean space that contains our universe, and obeys the two basic laws of classical physics: conservation of linear momentum, and conservation of total energy; the fluid is described by the classical wave equation (CWE), which was Schrödinger's first candidate to develop his quantum theory. Novel solutions for the CWE discovered twenty years ago are nonharmonic, inherently quantized, and universal in the sense of scale invariance, thus leading to quantization at all scales of the universe, from galactic clusters to the sub-quark world, and yielding a unified Lorentz-invariant quantum theory ab initio. Quingal solutions are isomorphic under both neo-Galilean and Lorentz transformations, and exhibit nother remarkable property: intrinsic unstability for large values of ℓ (a quantum number), thus limiting the size of each system at a given scale. Unstability and scale-invariance together lead to nested structures observed in our solar system; unstability may explain the small number of rows in the chemical periodic table, and nuclear unstability of nuclides beyond lead and bismuth. Quingal functions lend mathematical basis for Boscovich's unified force (which is compatible with many pieces of evidence collected over the past century), and also yield a simple geometrical solution for the classical three-body problem, which is a useful model for electronic orbits in simple diatomic molecules. A testable prediction for the helicoidal-type force is suggested.
Efficient and Flexible Computation of Many-Electron Wave Function Overlaps
2016-01-01
A new algorithm for the computation of the overlap between many-electron wave functions is described. This algorithm allows for the extensive use of recurring intermediates and thus provides high computational efficiency. Because of the general formalism employed, overlaps can be computed for varying wave function types, molecular orbitals, basis sets, and molecular geometries. This paves the way for efficiently computing nonadiabatic interaction terms for dynamics simulations. In addition, other application areas can be envisaged, such as the comparison of wave functions constructed at different levels of theory. Aside from explaining the algorithm and evaluating the performance, a detailed analysis of the numerical stability of wave function overlaps is carried out, and strategies for overcoming potential severe pitfalls due to displaced atoms and truncated wave functions are presented. PMID:26854874
Fractal dimensions of wave functions and local spectral measures on the Fibonacci chain
NASA Astrophysics Data System (ADS)
Macé, Nicolas; Jagannathan, Anuradha; Piéchon, Frédéric
2016-05-01
We present a theoretical framework for understanding the wave functions and spectrum of an extensively studied paradigm for quasiperiodic systems, namely the Fibonacci chain. Our analytical results, which are obtained in the limit of strong modulation of the hopping amplitudes, are in good agreement with published numerical data. In the perturbative limit, we show a symmetry of wave functions under permutation of site and energy indices. We compute the wave-function renormalization factors and from them deduce analytical expressions for the fractal exponents corresponding to individual wave functions, as well as their global averages. The multifractality of wave functions is seen to appear at next-to-leading order in ρ . Exponents for the local spectral density are given, in extremely good accord with numerical calculations. Interestingly, our analytical results for exponents are observed to describe the system rather well even for values of ρ well outside the domain of applicability of perturbation theory.
Nuclear correlation functions in lattice QCD
Detmold, William; Orginos, Konstantinos
2013-06-01
We consider the problem of calculating the large number of Wick contractions necessary to compute states with the quantum numbers of many baryons in lattice QCD. We consider a constructive approach and a determinant-based approach and show that these methods allow the required contractions to be performed for certain choices of interpolating operators. Examples of correlation functions computed using these techniques are shown for the quantum numbers of the light nuclei, $^4$He, $^8$Be, $^{12}$C, $^{16}$O and $^{28}$Si.
Nuclear cardiology: Myocardial perfusion and function
Seldin, D.W. )
1991-08-01
Myocardial perfusion studies continue to be a major focus of research, with new investigations of the relationship of exercise-redistribution thallium imaging to diagnosis, prognosis, and case management. The redistribution phenomenon, which seemed to be fairly well understood a few years ago, is now recognized to be much more complex than originally thought, and various strategies have been proposed to clarify the meaning of persistent defects. Pharmacologic intervention with dipyridamole and adenosine has become available as an alternative to exercise, and comparisons with exercise imaging and catheterization results have been described. Thallium itself is no longer the sole single-photon perfusion radiopharmaceutical; two new technetium agents are now widely available. In addition to perfusion studies, advances in the study of ventricular function have been made, including reports of studies performed in conjunction with technetium perfusion studies, new insights into cardiac physiology, and the prognostic and case-management information that function studies provide. Finally, work has continued with monoclonal antibodies for the identification of areas of myocyte necrosis. 41 references.
Argonov, V. Yu.
2014-11-15
The wave function of a moderately cold atom in a stationary near-resonant standing light wave delocalizes very fast due to wave packet splitting. However, we show that frequency modulation of the field can suppress packet splitting for some atoms whose specific velocities are in a narrow range. These atoms remain localized in a small space for a long time. We demonstrate and explain this effect numerically and analytically. We also demonstrate that the modulated field can not only trap but also cool the atoms. We perform a numerical experiment with a large atomic ensemble having wide initial velocity and energy distributions. During the experiment, most of atoms leave the wave while the trapped atoms have a narrow energy distribution.
A-dependence of weak nuclear structure functions
Haider, H.; Athar, M. Sajjad; Simo, I. Ruiz
2015-05-15
Effect of nuclear medium on the weak structure functions F{sub 2}{sup A}(x, Q{sup 2}) and F{sub 3}{sup A}(x, Q{sup 2}) have been studied using charged current (anti)neutrino deep inelastic scattering on various nuclear targets. Relativistic nuclear spectral function which incorporate Fermi motion, binding and nucleon correlations are used for the calculations. We also consider the pion and rho meson cloud contributions calculated from a microscopic model for meson-nucleus self-energies. Using these structure functions, F{sub i}{sup A}/F{sub i}{sup proton} and F{sub i}{sup A}/F{sub i}{sup deuteron}(i=2,3, A={sup 12}C, {sup 16}O, CH and H{sub 2}O) are obtained.
Submillimeter-Wave Spectroscopic Instruments: Multi-functional Atmospheric Characterization
NASA Astrophysics Data System (ADS)
Mehdi, I.; Gulkis, S.; Allen, M. A.; Schlecht, E.; Chattopadhyay, G.
2012-10-01
Submillimeter-wave spectroscopic instruments provide unique capability in terms of providing quantitative measurements of trace gas compositions in planetary atmospheres. Such instruments also provide temporal and wind velocity mapping capability.
NASA Astrophysics Data System (ADS)
Bernardino, M. J.; Jones, C. H.
2013-12-01
Past seismic studies attempting to image the lithosphere underneath the Sierra Nevada and to constrain the geometry of the upper mantle Isabella anomaly, a high wave-speed body underneath the western foothills of the range, have observed complex behavior in teleseismic and regional waveforms recorded at stations within the range. Notably, a 1993 teleseismic mini-array recorded multipath P-wave arrivals, topographic reflections, and scattered energy ~25 km west of the Sierran crest. These effects suggest wave propagation through strongly heterogeneous lithosphere complicated by near-surface phenomena. Multipathing and other complex wave propagation are indicative of strong variations in wavespeed, which in turn reflect structural complexity important in understanding the genesis of the Isabella anomaly. However, determining the extent of such propagative behavior in and underneath the Sierra Nevada has not been studied. We investigate the behavior of teleseismic P-waves using vertical-component receiver functions in an effort to better understand the extent of complex waveforms as a first tool in better constraining the geographic region(s) where sufficiently complex lithospheric structure exists. We expect that the presence of sufficiently high velocity gradients should result in P-wave multipath arrivals from events that skirt the perimeter of the Isabella anomaly from certain backazimuths. We deconvolve regionally beamed vertical P-waveforms from individual vertical component P-waves. This effectively recovers variability in the P waveforms that is normally lost in typical single-station radial- and transverse-component receiver function analyses. Vertical P-wave beams are constructed using dbxcor, a waveform correlation algorithm developed by G. Pavlis. Seismic data for the northern and central Sierra Nevada are from the 2005-2007 Sierra Nevada Earthscope Project (SNEP) and further supplemented by many permanent and temporary stations including the Earthscope
Thermoelastic Stress in a Functionally Graded Infinite Plate with Electromagnetic Wave Absorption
NASA Astrophysics Data System (ADS)
Tian, Hong-Yan; Wang, Xing-Zhe; Zhou, You-He
2012-11-01
We present an analysis of thermal and thermoelastic behaviors of a functionally graded infinite plate taking into account electromagnetic wave absorption. To treat with the inhomogeneity of functionally graded wave-absorbing (FGWA) materials, the plate is approximated by subdividing it into thin homogeneous layers to solve the governing equations together with proper boundary and connecting conditions. The results illustrate that the FGWA plate is a broadband type absorber with electromagnetic wave absorption. By choosing proper material gradation character and the thickness of the FGWA plate, it is possible to obtain a good performance of electromagnetic wave absorption and thermoelastic stress characteristics.
NASA Astrophysics Data System (ADS)
Gross, Franz; Stadler, Alfred
2010-09-01
We present the effective range expansions for the 1S0 and 3S1 scattering phase shifts, and the relativistic deuteron wave functions that accompany our recent high precision fits (with χ2/Ndata≃1) to the 2007 world np data below 350 MeV. The wave functions are expanded in a series of analytical functions (with the correct asymptotic behavior at both large and small arguments) that can be Fourier-transformed from momentum to coordinate space and are convenient to use in any application. A fortran subroutine to compute these wave functions can be obtained from the authors.
Franz Gross, Alfred Stadler
2010-09-01
We present the effective range expansions for the 1S0 and 3S1 scattering phase shifts, and the relativistic deuteron wave functions that accompany our recent high precision fits (with \\chi^2/N{data} \\simeq 1) to the 2007 world np data below 350 MeV. The wave functions are expanded in a series of analytical functions (with the correct asymptotic behavior at both large and small arguments) that can be Fourier-transformed from momentum to coordinate space and are convenient to use in any application. A fortran subroutine to compute these wave functions can be obtained from the authors.
Numerical methods for the calculation of special functions of wave catastrophes
NASA Astrophysics Data System (ADS)
Ipatov, E. B.; Lukin, D. S.; Palkin, E. A.
1985-02-01
The paper investigates the properties of special functions which are used for the asymptotic description of the structure of wave fields near various types of focusings. These functions are realized in software packages for the BESM-6 computer using FORTRAN. The canonical equations and basic properties of these functions are examined along with the development of numerical algorithms for their computation. These functions may be applied in the study of various types of wave problems, including: (1) radio wave propagation in the ionosphere and ionospheric waveguide channels; (2) the fine structure of sound fields in an acoustic duct; and (3) the focusing of laser radiation reflected from a rough surface.
Probability function of breaking-limited surface elevation. [wind generated waves of ocean
NASA Technical Reports Server (NTRS)
Tung, C. C.; Huang, N. E.; Yuan, Y.; Long, S. R.
1989-01-01
The effect of wave breaking on the probability function of surface elevation is examined. The surface elevation limited by wave breaking zeta sub b(t) is first related to the original wave elevation zeta(t) and its second derivative. An approximate, second-order, nonlinear, non-Gaussian model for zeta(t) of arbitrary but moderate bandwidth is presented, and an expression for the probability density function zeta sub b(t) is derived. The results show clearly that the effect of wave breaking on the probability density function of surface elevation is to introduce a secondary hump on the positive side of the probability density function, a phenomenon also observed in wind wave tank experiments.
Rezende, Carlos A; San Gil, Rosane A S; Borré, Leandro B; Pires, José Ricardo; Vaiss, Viviane S; Resende, Jackson A L C; Leitão, Alexandre A; De Alencastro, Ricardo B; Leal, Katia Z
2016-09-01
The experiments of carvedilol form II, form III, and hydrate by (13)C and (15)N cross-polarization magic-angle spinning (CP MAS) are reported. The GIPAW (gauge-including projector-augmented wave) method from DFT (density functional theory) calculations was used to simulate (13)C and (15)N chemical shifts. A very good agreement was found for the comparison between the global results of experimental and calculated nuclear magnetic resonance (NMR) chemical shifts for carvedilol polymorphs. This work aims a comprehensive understanding of carvedilol crystalline forms employing solution and solid-state NMR as well as DFT calculations. PMID:26372719
Quantum-defect functions. Interconverters of electronic and nuclear motion
Dill, D.; Jungen, C.
1980-08-21
In 1964 Mulliken systematically extended the ideas of Rydberg states and quantum defects from atoms to molecules. The key point of that extension is stated in several sentences: In molecules...all that has just been stated for atomic Rydberg states finds a parallel if one considers any one fixed nuclear configuration... However the mode of variation of the MOs and their energies as one varies the nuclear configuration is a new feature of interest. A complication...is the fact that the interaction of the molecular rotation with the l vector of the Rydberg electron changes radically as n increases in a Rydberg series. Thereby Mulliken introduced the concept of the quantum-defect function, ..mu lambda..(R), depending on nuclear configuration R and orbital-momentum projection ..lambda.. along the molecular axis. This concept has emerged as central to the understanding of the interconversion of electronic and nuclear motion in molecular systems. 13 figures.
Comparison of quasi-Hartree-Fock wave-functions for lithium hydride
NASA Astrophysics Data System (ADS)
Asthalter, T.; Weyrich, W.; Harker, A. H.; Kunz, A. B.; Orlando, R.; Pisani, C.
1992-09-01
We compare the Hartree-Fock wave-functions for crystalline LiH obtained either with a standard Crystalline-Orbital—LCAO procedure or following the Adams-Gilbert-Kunz (AGK) prescription. Total energy, band-structure, reciprocal form factors [ B( r)] are taken as a reference, for checking the quality of the wave-function. The influence of the inclusion of high angular-quantum-number functions in the AGK basis set is explored.
Public meetings on nuclear waste management: their function and organization
Duvernoy, E.G.; Marcus, A.A.; Overcast, T.; Schilling, A.H.
1981-05-01
This report focuses on public meetings as a vehicle for public participation in nuclear waste management. The nature of public meetings is reviewed and the functions served by meetings highlighted. The range of participants and their concerns are addressed, including a review of the participants from past nuclear waste management meetings. A sound understanding of the expected participants allows DOE to tailor elements of the meeting, such as notification, format, and agenda to accommodate the attendees. Finally, the report discusses the organization of public meetings on nuclear waste management in order to enhance the DOE's functions for such meetings. Possible structures are suggested for a variety of elements that are relevant prior to, during and after the public meeting. These suggestions are intended to supplement the DOE Public Participation Manual.
BUILDING A UNIVERSAL NUCLEAR ENERGY DENSITY FUNCTIONAL (UNEDF)
Nazarewicz, Witold
2012-07-01
The long-term vision initiated with UNEDF is to arrive at a comprehensive, quantitative, and unified description of nuclei and their reactions, grounded in the fundamental interactions between the constituent nucleons. We seek to replace current phenomenological models of nuclear structure and reactions with a well-founded microscopic theory that delivers maximum predictive power with well-quantified uncertainties. Specifically, the mission of this project has been three-fold: First, to find an optimal energy density functional (EDF) using all our knowledge of the nucleonic Hamiltonian and basic nuclear properties. Second, to apply the EDF theory and its extensions to validate the functional using all the available relevant nuclear structure and reaction data. Third, to apply the validated theory to properties of interest that cannot be measured, in particular the properties needed for reaction theory.
Uncertainty Quantification and Propagation in Nuclear Density Functional Theory
Schunck, N; McDonnell, J D; Higdon, D; Sarich, J; Wild, S M
2015-03-17
Nuclear density functional theory (DFT) is one of the main theoretical tools used to study the properties of heavy and superheavy elements, or to describe the structure of nuclei far from stability. While on-going eff orts seek to better root nuclear DFT in the theory of nuclear forces, energy functionals remain semi-phenomenological constructions that depend on a set of parameters adjusted to experimental data in fi nite nuclei. In this paper, we review recent eff orts to quantify the related uncertainties, and propagate them to model predictions. In particular, we cover the topics of parameter estimation for inverse problems, statistical analysis of model uncertainties and Bayesian inference methods. Illustrative examples are taken from the literature.
Longitudinal wave function control in single quantum dots with an applied magnetic field
Cao, Shuo; Tang, Jing; Gao, Yunan; Sun, Yue; Qiu, Kangsheng; Zhao, Yanhui; He, Min; Shi, Jin-An; Gu, Lin; Williams, David A.; Sheng, Weidong; Jin, Kuijuan; Xu, Xiulai
2015-01-01
Controlling single-particle wave functions in single semiconductor quantum dots is in demand to implement solid-state quantum information processing and spintronics. Normally, particle wave functions can be tuned transversely by an perpendicular magnetic field. We report a longitudinal wave function control in single quantum dots with a magnetic field. For a pure InAs quantum dot with a shape of pyramid or truncated pyramid, the hole wave function always occupies the base because of the less confinement at base, which induces a permanent dipole oriented from base to apex. With applying magnetic field along the base-apex direction, the hole wave function shrinks in the base plane. Because of the linear changing of the confinement for hole wave function from base to apex, the center of effective mass moves up during shrinking process. Due to the uniform confine potential for electrons, the center of effective mass of electrons does not move much, which results in a permanent dipole moment change and an inverted electron-hole alignment along the magnetic field direction. Manipulating the wave function longitudinally not only provides an alternative way to control the charge distribution with magnetic field but also a new method to tune electron-hole interaction in single quantum dots. PMID:25624018
Coherent molecular transistor: Control through variation of the gate wave function
Ernzerhof, Matthias
2014-03-21
In quantum interference transistors (QUITs), the current through the device is controlled by variation of the gate component of the wave function that interferes with the wave function component joining the source and the sink. Initially, mesoscopic QUITs have been studied and more recently, QUITs at the molecular scale have been proposed and implemented. Typically, in these devices the gate lead is subjected to externally adjustable physical parameters that permit interference control through modifications of the gate wave function. Here, we present an alternative model of a molecular QUIT in which the gate wave function is directly considered as a variable and the transistor operation is discussed in terms of this variable. This implies that we specify the gate current as well as the phase of the gate wave function component and calculate the resulting current through the source-sink channel. Thus, we extend on prior works that focus on the phase of the gate wave function component as a control parameter while having zero or certain discrete values of the current. We address a large class of systems, including finite graphene flakes, and obtain analytic solutions for how the gate wave function controls the transistor.
NASA Astrophysics Data System (ADS)
Zhao, Lian-Feng; Xie, Xiao-Bi; Tian, Bao-Feng; Chen, Qi-Fu; Hao, Tian-Yao; Yao, Zhen-Xing
2015-11-01
We investigate the geometric spreading and attenuation of seismic Pn waves in Northeast China and the Korean Peninsula. A high-quality broadband Pn wave data set generated by North Korean nuclear tests is used to constrain the parameters of a frequency-dependent log-quadratic geometric spreading function and a power law Pn Q model. The geometric spreading function and apparent Pn wave Q are obtained for Northeast China and the Korean Peninsula between 2.0 and 10.0 Hz. Using the two-station amplitude ratios of the Pn spectra and correcting them with the known spreading function, we remove the contributions of the source and crust from the apparent Pn Q and retrieve the P wave attenuation information along the pure upper mantle path. We then use both Pn amplitudes and amplitude ratios in a tomographic approach to obtain the upper mantle P wave attenuation in the studied area. The Pn wave spectra observed in China are compared with those recorded in Japan, and the result reveals that the high-frequency Pn signal across the oceanic path attenuated faster compared with those through the continental path.
Reflection-Asymmetric Nuclear Deformations within the Density Functional Theory
Olsen, E; Erler, J; Nazarewicz, W.; Stoitsov, M
2012-01-01
Within the nuclear density functional theory (DFT) we study the effect of reflection- asymmetric shapes on ground-state binding energies and binding energy differences. To this end, we developed the new DFT solver axialhfb that uses an approximate second-order gradient to solve the Hartree-Fock-Bogoliubov equations of superconducting DFT with the quasi-local Skyrme energy density functionals. Illustrative calculations are carried out for even- even isotopes of radium and thorium.
Nanotopographical Modulation of Cell Function through Nuclear Deformation
Wang, Kai; Bruce, Allison; Mezan, Ryan; Kadiyala, Anand; Wang, Liying; Dawson, Jeremy; Rojanasakul, Yon; Yang, Yong
2016-01-01
Although nanotopography has been shown to be a potent modulator of cell behavior, it is unclear how the nanotopographical cue, through focal adhesions, affects the nucleus, eventually influencing cell phenotype and function. Thus, current methods to apply nanotopography to regulate cell behavior are basically empirical. We, herein, engineered nanotopographies of various shapes (gratings and pillars) and dimensions (feature size, spacing and height), and thoroughly investigated cell spreading, focal adhesion organization and nuclear deformation of human primary fibroblasts as the model cell grown on the nanotopographies. We examined the correlation between nuclear deformation and cell functions such as cell proliferation, transfection and extracellular matrix protein type I collagen production. It was found that the nanoscale gratings and pillars could facilitate focal adhesion elongation by providing anchoring sites, and the nanogratings could orient focal adhesions and nuclei along the nanograting direction, depending on not only the feature size but also the spacing of the nanogratings. Compared with continuous nanogratings, discrete nanopillars tended to disrupt the formation and growth of focal adhesions and thus had less profound effects on nuclear deformation. Notably, nuclear volume could be effectively modulated by the height of nanotopography. Further, we demonstrated that cell proliferation, transfection, and type I collagen production were strongly associated with the nuclear volume, indicating that the nucleus serves as a critical mechanosensor for cell regulation. Our study delineated the relationships between focal adhesions, nucleus and cell function and highlighted that the nanotopography could regulate cell phenotype and function by modulating nuclear deformation. This study provides insight into the rational design of nanotopography for new biomaterials and the cell–substrate interfaces of implants and medical devices. PMID:26844365
Goal Direction and Effectiveness, Emotional Maturity, and Nuclear Family Functioning
ERIC Educational Resources Information Center
Klever, Phillip
2009-01-01
Differentiation of self, a cornerstone concept in Bowen theory, has a profound influence over time on the functioning of the individual and his or her family unit. This 5-year longitudinal study tested this hypothesis with 50 developing nuclear families. The dimensions of differentiation of self that were examined were goal direction and…
Wave Distribution Functions of Plasmaspheric Hiss and their Effects on Radiation Belt Dynamics
NASA Astrophysics Data System (ADS)
Santolik, O.; Ripoll, J. F.; Kurth, W. S.; Hospodarsky, G. B.; Kletzing, C.
2015-12-01
Plasmaspheric hiss is formed by whistler-mode waves which play an important role in the dynamics the Earth's radiation belts, specifically in connection with the slot region between the inner and outer Van Allen belts. The origin of plasmaspheric hiss is still a subject of discussions and these waves are known for their complex propagation properties. They are often far from a single plane wave approximation, forming a continuous distribution of the wave energy density with respect to the wave vector direction (wave distribution function). Analysis of polarization and propagation parameters of these waves provides us with inputs for modeling of radiation belt dynamics. We use the data of the Waves instrument of Electric and Magnetic Field Instrument Suite and Integrated Science (EMFISIS) onboard the Van Allen Probes spacecraft, to analyze simultaneous measurements of all electric and magnetic field components, together with measurements of the plasma density based on the determination of the upper hybrid resonance frequency. Using this unique data set we estimate the wave distribution functions of plasmaspheric hiss and we model the effects of these waves on the decay rates of radiation belt electrons through quasilinear pitch angle diffusion.
Protective measurement of the wave function of a single squeezed harmonic-oscillator state
NASA Astrophysics Data System (ADS)
Alter, Orly; Yamamoto, Yoshihisa
1996-05-01
A scheme for the "protective measurement"
NASA Astrophysics Data System (ADS)
Shchadilova, Yulia E.; Grusdt, Fabian; Rubtsov, Alexey N.; Demler, Eugene
2016-04-01
We propose a class of variational Gaussian wave functions to describe Fröhlich polarons at finite momenta. Our wave functions give polaron energies that are in excellent agreement with the existing Monte Carlo results for a broad range of interactions. We calculate the effective mass of polarons and find smooth crossover between weak- and intermediate-coupling strength. Effective masses that we obtain are considerably larger than those predicted by the mean-field method. A prediction based on our variational wave functions is a special pattern of correlations between host atoms that can be measured in time-of-flight experiments.
Degenerate RS perturbation theory. [Rayleigh-Schroedinger energies and wave functions
NASA Technical Reports Server (NTRS)
Hirschfelder, J. O.; Certain, P. R.
1974-01-01
A concise, systematic procedure is given for determining the Rayleigh-Schroedinger energies and wave functions of degenerate states to arbitrarily high orders even when the degeneracies of the various states are resolved in arbitrary orders. The procedure is expressed in terms of an iterative cycle in which the energy through the (2n + 1)-th order is expressed in terms of the partially determined wave function through the n-th order. Both a direct and an operator derivation are given. The two approaches are equivalent and can be transcribed into each other. The direct approach deals with the wave functions (without the use of formal operators) and has the advantage that it resembles the usual treatment of nondegenerate perturbations and maintains close contact with the basic physics. In the operator approach, the wave functions are expressed in terms of infinite-order operators which are determined by the successive resolution of the space of the zeroth-order functions.
Ocean wave-radar modulation transfer functions from the West Coast experiment
NASA Technical Reports Server (NTRS)
Wright, J. W.; Plant, W. J.; Keller, W. C.; Jones, W. L.
1980-01-01
Short gravity-capillary waves, the equilibrium, or the steady state excitations of the ocean surface are modulated by longer ocean waves. These short waves are the predominant microwave scatterers on the ocean surface under many viewing conditions so that the modulation is readily measured with CW Doppler radar used as a two-scale wave probe. Modulation transfer functions (the ratio of the cross spectrum of the line-of-sight orbital speed and backscattered microwave power to the autospectrum of the line-of-sight orbital speed) were measured at 9.375 and 1.5 GHz (Bragg wavelengths of 2.3 and 13 cm) for winds up to 10 m/s and ocean wave periods from 2-18 s. The measurements were compared with the relaxation-time model; the principal result is that a source of modulation other than straining by the horizontal component of orbital speed, possibly the wave-induced airflow, is responsible for most of the modulation by waves of typical ocean wave period (10 s). The modulations are large; for unit coherence, spectra of radar images of deep-water waves should be proportional to the quotient of the slope spectra of the ocean waves by the ocean wave frequency.
Data synthesis and display programs for wave distribution function analysis
NASA Technical Reports Server (NTRS)
Storey, L. R. O.; Yeh, K. J.
1992-01-01
At the National Space Science Data Center (NSSDC) software was written to synthesize and display artificial data for use in developing the methodology of wave distribution analysis. The software comprises two separate interactive programs, one for data synthesis and the other for data display.
McKechnie, Scott; Booth, George H; Cohen, Aron J; Cole, Jacqueline M
2015-05-21
The best practice in computational methods for determining vertical ionization energies (VIEs) is assessed, via reference to experimentally determined VIEs that are corroborated by highly accurate coupled-cluster calculations. These reference values are used to benchmark the performance of density functional theory (DFT) and wave function methods: Hartree-Fock theory, second-order Møller-Plesset perturbation theory, and Electron Propagator Theory (EPT). The core test set consists of 147 small molecules. An extended set of six larger molecules, from benzene to hexacene, is also considered to investigate the dependence of the results on molecule size. The closest agreement with experiment is found for ionization energies obtained from total energy difference calculations. In particular, DFT calculations using exchange-correlation functionals with either a large amount of exact exchange or long-range correction perform best. The results from these functionals are also the least sensitive to an increase in molecule size. In general, ionization energies calculated directly from the orbital energies of the neutral species are less accurate and more sensitive to an increase in molecule size. For the single-calculation approach, the EPT calculations are in closest agreement for both sets of molecules. For the orbital energies from DFT functionals, only those with long-range correction give quantitative agreement with dramatic failing for all other functionals considered. The results offer a practical hierarchy of approximations for the calculation of vertical ionization energies. In addition, the experimental and computational reference values can be used as a standardized set of benchmarks, against which other approximate methods can be compared. PMID:26001454
McKechnie, Scott; Booth, George H.; Cohen, Aron J.; Cole, Jacqueline M.
2015-05-21
The best practice in computational methods for determining vertical ionization energies (VIEs) is assessed, via reference to experimentally determined VIEs that are corroborated by highly accurate coupled-cluster calculations. These reference values are used to benchmark the performance of density functional theory (DFT) and wave function methods: Hartree-Fock theory, second-order Møller-Plesset perturbation theory, and Electron Propagator Theory (EPT). The core test set consists of 147 small molecules. An extended set of six larger molecules, from benzene to hexacene, is also considered to investigate the dependence of the results on molecule size. The closest agreement with experiment is found for ionization energies obtained from total energy difference calculations. In particular, DFT calculations using exchange-correlation functionals with either a large amount of exact exchange or long-range correction perform best. The results from these functionals are also the least sensitive to an increase in molecule size. In general, ionization energies calculated directly from the orbital energies of the neutral species are less accurate and more sensitive to an increase in molecule size. For the single-calculation approach, the EPT calculations are in closest agreement for both sets of molecules. For the orbital energies from DFT functionals, only those with long-range correction give quantitative agreement with dramatic failing for all other functionals considered. The results offer a practical hierarchy of approximations for the calculation of vertical ionization energies. In addition, the experimental and computational reference values can be used as a standardized set of benchmarks, against which other approximate methods can be compared.
Nuclear Functions of Nucleolin through Global Proteomics and Interactomic Approaches.
Salvetti, Anna; Couté, Yohann; Epstein, Alberto; Arata, Loredana; Kraut, Alexandra; Navratil, Vincent; Bouvet, Philippe; Greco, Anna
2016-05-01
Nucleolin (NCL) is a major component of the cell nucleolus, which has the ability to rapidly shuttle to several other cells' compartments. NCL plays important roles in a variety of essential functions, among which are ribosome biogenesis, gene expression, and cell growth. However, the precise mechanisms underlying NCL functions are still unclear. Our study aimed to provide new information on NCL functions via the identification of its nuclear interacting partners. Using an interactomics approach, we identified 140 proteins co-purified with NCL, among which 100 of them were specifically found to be associated with NCL after RNase digestion. The functional classification of these proteins confirmed the prominent role of NCL in ribosome biogenesis and additionally revealed the possible involvement of nuclear NCL in several pre-mRNA processing pathways through its interaction with RNA helicases and proteins participating in pre-mRNA splicing, transport, or stability. NCL knockdown experiments revealed that NCL regulates the localization of EXOSC10 and the amount of ZC3HAV1, two components of the RNA exosome, further suggesting its involvement in the control of mRNA stability. Altogether, this study describes the first nuclear interactome of human NCL and provides the basis for further understanding the mechanisms underlying the essential functions of this nucleolar protein. PMID:27049334
Nuclear cyclophilins affect spliceosome assembly and function in vitro
Adams, B.M.; Coates, Miranda N.; Jackson, S. RaElle; Jurica, Melissa S.; Davis, Tara L.
2015-01-01
Cyclophilins are ubiquitously expressed proteins that bind to prolines and can catalyse cis/trans isomerization of proline residues. There are 17 annotated members of the cyclophilin family in humans, ubiquitously expressed and localized variously to the cytoplasm, nucleus or mitochondria. Surprisingly, all eight of the nuclear localized cyclophilins are found associated with spliceosomal complexes. However, their particular functions within this context are unknown. We have therefore adapted three established assays for in vitro pre-mRNA splicing to probe the functional roles of nuclear cyclophilins in the context of the human spliceosome. We find that four of the eight spliceosom-associated cyclophilins exert strong effects on splicing in vitro. These effects are dose-dependent and, remarkably, uniquely characteristic of each cyclophilin. Using both qualitative and quantitative means, we show that at least half of the nuclear cyclophilins can act as regulatory factors of spliceosome function in vitro. The present work provides the first quantifiable evidence that nuclear cyclophilins are splicing factors and provides a novel approach for future work into small molecule-based modulation of pre-mRNA splicing. PMID:25967372
Building A Universal Nuclear Energy Density Functional (UNEDF)
Joe Carlson; Dick Furnstahl; Mihai Horoi; Rusty Lusk; Witek Nazarewicz; Esmond Ng; Ian Thompson; James Vary
2012-09-30
During the period of Dec. 1 2006 - Jun. 30, 2012, the UNEDF collaboration carried out a comprehensive study of all nuclei, based on the most accurate knowledge of the strong nuclear interaction, the most reliable theoretical approaches, the most advanced algorithms, and extensive computational resources, with a view towards scaling to the petaflop platforms and beyond. The long-term vision initiated with UNEDF is to arrive at a comprehensive, quantitative, and unified description of nuclei and their reactions, grounded in the fundamental interactions between the constituent nucleons. We seek to replace current phenomenological models of nuclear structure and reactions with a well-founded microscopic theory that delivers maximum predictive power with well-quantified uncertainties. Specifically, the mission of this project has been three-fold: first, to find an optimal energy density functional (EDF) using all our knowledge of the nucleonic Hamiltonian and basic nuclear properties; second, to apply the EDF theory and its extensions to validate the functional using all the available relevant nuclear structure and reaction data; third, to apply the validated theory to properties of interest that cannot be measured, in particular the properties needed for reaction theory. The main physics areas of UNEDF, defined at the beginning of the project, were: ab initio structure; ab initio functionals; DFT applications; DFT extensions; reactions.
NASA Astrophysics Data System (ADS)
Yang, S. Y.; Liu, X.; Cao, D. F.; Mei, H.; Lei, Z. T.; Liu, L. S.
2013-03-01
The development of Functionally Graded Materials (FGM) for energy-absorbing applications requires understanding of stress wave propagation in these structures in order to optimize their resistance to failure. One-dimensional stress wave in FGM composites under elastic and plastic wave loading have been investigated. The stress distributions through the thickness and stress status have been analyzed and some comparisons have been done with the materials of sharp interfaces (two-layered material). The results demonstrate that the gradient structure design greatly decreases the severity of the stress concentrations at the interfaces and there are no clear differences in stress distribution in FGM composites under elastic and plastic wave loading.
NASA Astrophysics Data System (ADS)
Ramezanpour, A.
2016-06-01
We study the inverse problem of constructing an appropriate Hamiltonian from a physically reasonable set of orthogonal wave functions for a quantum spin system. Usually, we are given a local Hamiltonian and our goal is to characterize the relevant wave functions and energies (the spectrum) of the system. Here, we take the opposite approach; starting from a reasonable collection of orthogonal wave functions, we try to characterize the associated parent Hamiltonians, to see how the wave functions and the energy values affect the structure of the parent Hamiltonian. Specifically, we obtain (quasi) local Hamiltonians by a complete set of (multilayer) product states and a local mapping of the energy values to the wave functions. On the other hand, a complete set of tree wave functions (having a tree structure) results to nonlocal Hamiltonians and operators which flip simultaneously all the spins in a single branch of the tree graph. We observe that even for a given set of basis states, the energy spectrum can significantly change the nature of interactions in the Hamiltonian. These effects can be exploited in a quantum engineering problem optimizing an objective functional of the Hamiltonian.
A Study of Regional Wave Source Time Functions of Central Asian Earthquakes
NASA Astrophysics Data System (ADS)
Xie, J.; Perry, M. R.; Schult, F. R.; Wood, J.
2014-12-01
Despite the extensive use of seismic regional waves in seismic event identification and attenuation tomography, very little is known on how seismic sources radiate energy into these waves. For example, whether regional Lg wave has the same source spectrum as that of the local S has been questioned by Harr et al. and Frenkel et al. three decades ago; many current investigators assume source spectra in Lg, Sn, Pg, Pn and Lg coda waves have either the same or very similar corner frequencies, in contrast to local P and S spectra whose corner frequencies differ. The most complete information on how the finite source ruptures radiate energy into regional waves is contained in the time domain source time functions (STFs). To estimate the STFs of regional waves using the empirical Green's function (EGF) method, we have been substantially modifying a semi-automotive computer procedure to cope with the increasingly diverse and inconsistent naming patterns of new data files from the IRIS DMC. We are applying the modified procedure to many earthquakes in central Asia to study the STFs of various regional waves to see whether they have the same durations and pulse shapes, and how frequently source directivity occur. When applicable, we also examine the differences between STFs of local P and S waves and those of regional waves. The result of these analyses will be presented at the meeting.
Wave functions of symmetry-protected topological phases from conformal field theories
NASA Astrophysics Data System (ADS)
Scaffidi, Thomas; Ringel, Zohar
2016-03-01
We propose a method for analyzing two-dimensional symmetry-protected topological (SPT) wave functions using a correspondence with conformal field theories (CFTs) and integrable lattice models. This method generalizes the CFT approach for the fractional quantum Hall effect wherein the wave-function amplitude is written as a many-operator correlator in the CFT. Adopting a bottom-up approach, we start from various known microscopic wave functions of SPTs with discrete symmetries and show how the CFT description emerges at large scale, thereby revealing a deep connection between group cocycles and critical, sometimes integrable, models. We show that the CFT describing the bulk wave function is often also the one describing the entanglement spectrum, but not always. Using a plasma analogy, we also prove the existence of hidden quasi-long-range order for a large class of SPTs. Finally, we show how response to symmetry fluxes is easily described in terms of the CFT.
Approximate analytical time-domain Green's functions for the Caputo fractional wave equation.
Kelly, James F; McGough, Robert J
2016-08-01
The Caputo fractional wave equation [Geophys. J. R. Astron. Soc. 13, 529-539 (1967)] models power-law attenuation and dispersion for both viscoelastic and ultrasound wave propagation. The Caputo model can be derived from an underlying fractional constitutive equation and is causal. In this study, an approximate analytical time-domain Green's function is derived for the Caputo equation in three dimensions (3D) for power law exponents greater than one. The Green's function consists of a shifted and scaled maximally skewed stable distribution multiplied by a spherical spreading factor 1/(4πR). The approximate one dimensional (1D) and two dimensional (2D) Green's functions are also computed in terms of stable distributions. Finally, this Green's function is decomposed into a loss component and a diffraction component, revealing that the Caputo wave equation may be approximated by a coupled lossless wave equation and a fractional diffusion equation. PMID:27586735
Second-Order Perturbation Theory for Generalized Active Space Self-Consistent-Field Wave Functions.
Ma, Dongxia; Li Manni, Giovanni; Olsen, Jeppe; Gagliardi, Laura
2016-07-12
A multireference second-order perturbation theory approach based on the generalized active space self-consistent-field (GASSCF) wave function is presented. Compared with the complete active space (CAS) and restricted active space (RAS) wave functions, GAS wave functions are more flexible and can employ larger active spaces and/or different truncations of the configuration interaction expansion. With GASSCF, one can explore chemical systems that are not affordable with either CASSCF or RASSCF. Perturbation theory to second order on top of GAS wave functions (GASPT2) has been implemented to recover the remaining electron correlation. The method has been benchmarked by computing the chromium dimer ground-state potential energy curve. These calculations show that GASPT2 gives results similar to CASPT2 even with a configuration interaction expansion much smaller than the corresponding CAS expansion. PMID:27276688
Projector augmented-wave method: Application to relativistic spin-density functional theory
NASA Astrophysics Data System (ADS)
Dal Corso, Andrea
2010-08-01
Applying the projector augmented-wave (PAW) method to relativistic spin-density functional theory (RSDFT) we derive PAW Dirac-Kohn-Sham equations for four-component spinor pseudo-wave-functions. The PAW freedom to add a vanishing operator inside the PAW spheres allows us to transform these PAW Dirac-type equations into PAW Pauli-type equations for two-component spinor pseudo-wave-functions. With these wave functions, we get the frozen-core energy as well as the charge and magnetization densities of RSDFT, with errors comparable to the largest between 1/c2 and the transferability error of the PAW data sets. Presently, the latter limits the accuracy of the calculations, not the use of the Pauli-type equations. The theory is validated by applications to isolated atoms of Fe, Pt, and Au, and to the band structure of fcc-Pt, fcc-Au, and ferromagnetic bcc-Fe.
Racine, Julien; Hagebaum-Reignier, Denis; Carissan, Yannick; Humbel, Stéphane
2016-03-30
A method is proposed to obtain coefficients and weights of valence bond (VB) determinants from multi configurational wave functions. This reading of the wave functions can apply to ground states as well as excited states. The method is based on projection operators. Both energetic and overlap-based criteria are used to assess the quality of the resulting VB wave function. The approach gives a simple access to a VB rewriting for low-lying states, and it is applied to the allyl cation, to the allyl radical and to the ethene (notably to the V-state). For these states, large overlap between VB and multi reference wave functions are easily obtained. The approach proves to be useful to propose an interpretation of the nature of the V-state of ethene. PMID:26786547
Wave function for dissipative harmonically confined electrons in a time-dependent electric field
NASA Astrophysics Data System (ADS)
Lai, Meng-Yun; Pan, Xiao-Yin; Li, Yu-Qi
2016-07-01
We investigate the many-body wave function of a dissipative system of interacting particles confined by a harmonic potential and perturbed by a time-dependent spatially homogeneous electric field. Applying the method of Yu and Sun (1994), it is found that the wave function is comprised of a phase factor times the solution to the unperturbed time-dependent (TD) Schrödinger equation with the latter being translated by a time-dependent value that satisfies the classical damped driven equation of motion, plus an addition fluctuation term due to the Brownian motion. The wave function reduces to that of the Harmonic Potential Theorem (HPT) wave function in the absence of the dissipation. An example of application of the results derived is also given.
Dipole polarizability of 120Sn and nuclear energy density functionals
NASA Astrophysics Data System (ADS)
Hashimoto, T.; Krumbholz, A. M.; Reinhard, P.-G.; Tamii, A.; von Neumann-Cosel, P.; Adachi, T.; Aoi, N.; Bertulani, C. A.; Fujita, H.; Fujita, Y.; GanioÇ§lu, E.; Hatanaka, K.; Ideguchi, E.; Iwamoto, C.; Kawabata, T.; Khai, N. T.; Krugmann, A.; Martin, D.; Matsubara, H.; Miki, K.; Neveling, R.; Okamura, H.; Ong, H. J.; Poltoratska, I.; Ponomarev, V. Yu.; Richter, A.; Sakaguchi, H.; Shimbara, Y.; Shimizu, Y.; Simonis, J.; Smit, F. D.; Süsoy, G.; Suzuki, T.; Thies, J. H.; Yosoi, M.; Zenihiro, J.
2015-09-01
The electric dipole strength distribution in 120Sn between 5 and 22 MeV has been determined at the Research Center for Nuclear Physics, Osaka, from polarization transfer observables measured in proton inelastic scattering at E0=295 MeV and forward angles including 0∘. Combined with photoabsorption data, a highly precise electric dipole polarizability αD(120Sn) =8.93 (36 ) fm3 is extracted. The dipole polarizability as isovector observable par excellence carries direct information on nuclear symmetry energy and its density dependence. The correlation of the new value with the well-established αD(208Pb) serves as a test of its prediction by nuclear energy density functionals. Models based on modern Skyrme interactions describe the data fairly well while most calculations based on relativistic Hamiltonians cannot.
sup 4 He- sup 4 He elastic scattering and variational wave functions
Usmani, A.A.; Ahmad, I. ); Usmani, Q.N. )
1992-01-01
We calculate differential cross sections for {sup 4}He-{sup 4}He elastic scattering at 4.32 GeV/{ital c} in the framework of Glauber multiple scattering theory using correlated variational wave functions as given by the two-nucleon Urbana {ital v}{sub 14} potential and the spin-isospin averaged Melfleit-Tjon force {ital V}. These wave functions are found to give fairly satisfactory results.
Miyake, Hirokazu; Siviloglou, Georgios A; Puentes, Graciana; Pritchard, David E; Ketterle, Wolfgang; Weld, David M
2011-10-21
We have observed Bragg scattering of photons from quantum degenerate ^{87}Rb atoms in a three-dimensional optical lattice. Bragg scattered light directly probes the microscopic crystal structure and atomic wave function whose position and momentum width is Heisenberg limited. The spatial coherence of the wave function leads to revivals in the Bragg scattered light due to the atomic Talbot effect. The decay of revivals across the superfluid to Mott insulator transition indicates the loss of superfluid coherence. PMID:22107532
SURFACE SYMMETRY ENERGY OF NUCLEAR ENERGY DENSITY FUNCTIONALS
Nikolov, N; Schunck, N; Nazarewicz, W; Bender, M; Pei, J
2010-12-20
We study the bulk deformation properties of the Skyrme nuclear energy density functionals. Following simple arguments based on the leptodermous expansion and liquid drop model, we apply the nuclear density functional theory to assess the role of the surface symmetry energy in nuclei. To this end, we validate the commonly used functional parametrizations against the data on excitation energies of superdeformed band-heads in Hg and Pb isotopes, and fission isomers in actinide nuclei. After subtracting shell effects, the results of our self-consistent calculations are consistent with macroscopic arguments and indicate that experimental data on strongly deformed configurations in neutron-rich nuclei are essential for optimizing future nuclear energy density functionals. The resulting survey provides a useful benchmark for further theoretical improvements. Unlike in nuclei close to the stability valley, whose macroscopic deformability hangs on the balance of surface and Coulomb terms, the deformability of neutron-rich nuclei strongly depends on the surface-symmetry energy; hence, its proper determination is crucial for the stability of deformed phases of the neutron-rich matter and description of fission rates for r-process nucleosynthesis.
Zhang, Y. S.; Cai, F.; Xu, W. M.
2011-09-28
The ship motion equation with a cosine wave excitement force describes the slip moments in regular waves. A new kind of wave excitement force model, with the form as sums of cosine functions was proposed to describe ship rolling in irregular waves. Ship rolling time series were obtained by solving the ship motion equation with the fourth-order-Runger-Kutta method. These rolling time series were synthetically analyzed with methods of phase-space track, power spectrum, primary component analysis, and the largest Lyapunove exponent. Simulation results show that ship rolling presents some chaotic characteristic when the wave excitement force was applied by sums of cosine functions. The result well explains the course of ship rolling's chaotic mechanism and is useful for ship hydrodynamic study.
Spent Nuclear Fuel Project Canister Storage Building Functions and Requirements
KLEM, M.J.
2000-10-18
In 1998, a major change in the technical strategy for managing Multi Canister Overpacks (MCO) while stored within the Canister Storage Building (CSB) occurred. The technical strategy is documented in Baseline Change Request (BCR) No. SNF-98-006, Simplified SNF Project Baseline (MCO Sealing) (FDH 1998). This BCR deleted the hot conditioning process initially adopted for the Spent Nuclear Fuel Project (SNF Project) as documented in WHC-SD-SNF-SP-005, Integrated Process Strategy for K Basins Spent Nuclear Fuel (WHC 199.5). In summary, MCOs containing Spent Nuclear Fuel (SNF) from K Basins would be placed in interim storage following processing through the Cold Vacuum Drying (CVD) facility. With this change, the needs for the Hot Conditioning System (HCS) and inerting/pressure retaining capabilities of the CSB storage tubes and the MCO Handling Machine (MHM) were eliminated. Mechanical seals will be used on the MCOs prior to transport to the CSB. Covers will be welded on the MCOs for the final seal at the CSB. Approval of BCR No. SNF-98-006, imposed the need to review and update the CSB functions and requirements baseline documented herein including changing the document title to ''Spent Nuclear Fuel Project Canister Storage Building Functions and Requirements.'' This revision aligns the functions and requirements baseline with the CSB Simplified SNF Project Baseline (MCO Sealing). This document represents the Canister Storage Building (CSB) Subproject technical baseline. It establishes the functions and requirements baseline for the implementation of the CSB Subproject. The document is organized in eight sections. Sections 1.0 Introduction and 2.0 Overview provide brief introductions to the document and the CSB Subproject. Sections 3.0 Functions, 4.0 Requirements, 5.0 Architecture, and 6.0 Interfaces provide the data described by their titles. Section 7.0 Glossary lists the acronyms and defines the terms used in this document. Section 8.0 References lists the
NASA Astrophysics Data System (ADS)
Gitterman, Yefim; Kim, So Gu; Hofstetter, Abraham
2014-05-01
Two underground nuclear explosions conducted by North Korea in 2009 and 2013 were recorded by the Israel Seismic Network. Pronounced coherent minima (spectral nulls) at 1.2-1.3 Hz were revealed in the spectra of teleseismic P-waves. For a ground-truth explosion with a shallow source depth (relatively to an earthquake), this phenomenon can be interpreted in terms of the interference between the down-going P-wave and the pP phase reflected from the Earth's surface. A similar effect was observed at ISN stations for the Pakistan nuclear explosion at a different frequency 1.7 Hz indicating a source and not site-effect. Similar spectral minima with about the same frequency were observed in teleseismic P-waves of all three North Korea explosions (including the 2006 test) recorded at network stations and arrays in Kazakhstan (KURK), Norway (NORESS, ARCESS), Australia (Alice Springs, Warramunga) and Canada (Yellowknife), covering a broad azimuthal range. Data of the 2013 test at Warramunga array showed harmonic spectral modulation with several minima, evidencing a clear interference effect. These observations support the above-mentioned interpretation. Based on the null frequency dependency on the near-surface acoustic velocity and the source depth, the depth of the North Korea tests was estimated as ~2 km (different from the value ~1 km reported by USGS for the third test). This unusual depth estimation needs an additional validation based on more stations and verification by other methods.
NASA Astrophysics Data System (ADS)
Francisco, E.; Pendás, A. Martín; Blanco, M. A.
2008-04-01
Given an N-electron molecule and an exhaustive partition of the real space ( R) into m arbitrary regions Ω,Ω,…,Ω ( ⋃i=1mΩ=R), the edf program computes all the probabilities P(n,n,…,n) of having exactly n electrons in Ω, n electrons in Ω,…, and n electrons ( n+n+⋯+n=N) in Ω. Each Ω may correspond to a single basin (atomic domain) or several such basins (functional group). In the later case, each atomic domain must belong to a single Ω. The program can manage both single- and multi-determinant wave functions which are read in from an aimpac-like wave function description ( .wfn) file (T.A. Keith et al., The AIMPAC95 programs, http://www.chemistry.mcmaster.ca/aimpac, 1995). For multi-determinantal wave functions a generalization of the original .wfn file has been introduced. The new format is completely backwards compatible, adding to the previous structure a description of the configuration interaction (CI) coefficients and the determinants of correlated wave functions. Besides the .wfn file, edf only needs the overlap integrals over all the atomic domains between the molecular orbitals (MO). After the P(n,n,…,n) probabilities are computed, edf obtains from them several magnitudes relevant to chemical bonding theory, such as average electronic populations and localization/delocalization indices. Regarding spin, edf may be used in two ways: with or without a splitting of the P(n,n,…,n) probabilities into α and β spin components. Program summaryProgram title: edf Catalogue identifier: AEAJ_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEAJ_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 5387 No. of bytes in distributed program, including test data, etc.: 52 381 Distribution format: tar.gz Programming language: Fortran 77 Computer
NASA Astrophysics Data System (ADS)
Van Raemdonck, Mario; Alcoba, Diego R.; Poelmans, Ward; De Baerdemacker, Stijn; Torre, Alicia; Lain, Luis; Massaccesi, Gustavo E.; Van Neck, Dimitri; Bultinck, Patrick
2015-09-01
A class of polynomial scaling methods that approximate Doubly Occupied Configuration Interaction (DOCI) wave functions and improve the description of dynamic correlation is introduced. The accuracy of the resulting wave functions is analysed by comparing energies and studying the overlap between the newly developed methods and full configuration interaction wave functions, showing that a low energy does not necessarily entail a good approximation of the exact wave function. Due to the dependence of DOCI wave functions on the single-particle basis chosen, several orbital optimisation algorithms are introduced. An energy-based algorithm using the simulated annealing method is used as a benchmark. As a computationally more affordable alternative, a seniority number minimising algorithm is developed and compared to the energy based one revealing that the seniority minimising orbital set performs well. Given a well-chosen orbital basis, it is shown that the newly developed DOCI based wave functions are especially suitable for the computationally efficient description of static correlation and to lesser extent dynamic correlation.
NASA Astrophysics Data System (ADS)
Mukherjee, Sutirtha; Mandal, Sudhansu
The internal structure and topology of the ground states for fractional quantum Hall effect (FQHE) are determined by the relative angular momenta between all the possible pairs of electrons. Laughlin wave function is the only known microscopic wave function for which these relative angular momenta are homogeneous (same) for any pair of electrons and depend solely on the filling factor. Without invoking any microscopic theory, considering only the relationship between number of flux quanta and particles in spherical geometry, and allowing the possibility of inhomogeneous (different) relative angular momenta between any two electrons, we develop a general method for determining a closed-form ground state wave function for any incompressible FQHE state. Our procedure provides variationally obtained very accurate wave functions, yet having simpler structure compared to any other known complex microscopic wave functions for the FQHE states. This method, thus, has potential in predicting a very accurate ground state wave function for the puzzling states such as the state at filling fraction 5/2. We acknowledge support from Department of Science and Technology, India.
Van Raemdonck, Mario; Alcoba, Diego R; Poelmans, Ward; De Baerdemacker, Stijn; Torre, Alicia; Lain, Luis; Massaccesi, Gustavo E; Van Neck, Dimitri; Bultinck, Patrick
2015-09-14
A class of polynomial scaling methods that approximate Doubly Occupied Configuration Interaction (DOCI) wave functions and improve the description of dynamic correlation is introduced. The accuracy of the resulting wave functions is analysed by comparing energies and studying the overlap between the newly developed methods and full configuration interaction wave functions, showing that a low energy does not necessarily entail a good approximation of the exact wave function. Due to the dependence of DOCI wave functions on the single-particle basis chosen, several orbital optimisation algorithms are introduced. An energy-based algorithm using the simulated annealing method is used as a benchmark. As a computationally more affordable alternative, a seniority number minimising algorithm is developed and compared to the energy based one revealing that the seniority minimising orbital set performs well. Given a well-chosen orbital basis, it is shown that the newly developed DOCI based wave functions are especially suitable for the computationally efficient description of static correlation and to lesser extent dynamic correlation. PMID:26374017
Exactness of wave functions from two-body exponential transformations in many-body quantum theory
Mazziotti, David A.
2004-01-01
Recent studies have considered the possibility that the exact ground-state wavefunction from any Hamiltonian with two-particle interactions may be generated from a single finite two-body exponential transformation acting on an arbitrary Slater determinant [Piecuch et al., Phys. Rev. Lett. 90, 113001 (2003)]. Using the Campbell-Baker-Hausdorff relation, we show that it is difficult for the variational minimum of this trial wave function to satisfy the contracted Schroedinger equation which is a necessary and sufficient condition for the wave function to satisfy the Schroedinger equation. A counterexample is presented through the Lipkin quasispin model with 4-50 fermions. When the number of fermions exceeds four, the wave function from a finite two-body exponential transformation is shown to be inexact. If the trial wave function ansatz is extended to include products of finite two-body exponential transformations acting on an arbitrary Slater-determinant reference, then we show that the ansatz includes the exact ground-state wave function from any Hamiltonian with only two-particle interactions. Connections between the two-body exponential transformation of the wave function and recent research on two-body exponential similarity transformations of the Hamiltonian [S.R. White, J. Chem. Phys. 117, 7472 (2002)] are discussed.
Modeling the Pulse Signal by Wave-Shape Function and Analyzing by Synchrosqueezing Transform.
Wu, Hau-Tieng; Wu, Han-Kuei; Wang, Chun-Li; Yang, Yueh-Lung; Wu, Wen-Hsiang; Tsai, Tung-Hu; Chang, Hen-Hong
2016-01-01
We apply the recently developed adaptive non-harmonic model based on the wave-shape function, as well as the time-frequency analysis tool called synchrosqueezing transform (SST) to model and analyze oscillatory physiological signals. To demonstrate how the model and algorithm work, we apply them to study the pulse wave signal. By extracting features called the spectral pulse signature, and based on functional regression, we characterize the hemodynamics from the radial pulse wave signals recorded by the sphygmomanometer. Analysis results suggest the potential of the proposed signal processing approach to extract health-related hemodynamics features. PMID:27304979
Modeling the Pulse Signal by Wave-Shape Function and Analyzing by Synchrosqueezing Transform
Wang, Chun-Li; Yang, Yueh-Lung; Wu, Wen-Hsiang; Tsai, Tung-Hu; Chang, Hen-Hong
2016-01-01
We apply the recently developed adaptive non-harmonic model based on the wave-shape function, as well as the time-frequency analysis tool called synchrosqueezing transform (SST) to model and analyze oscillatory physiological signals. To demonstrate how the model and algorithm work, we apply them to study the pulse wave signal. By extracting features called the spectral pulse signature, and based on functional regression, we characterize the hemodynamics from the radial pulse wave signals recorded by the sphygmomanometer. Analysis results suggest the potential of the proposed signal processing approach to extract health-related hemodynamics features. PMID:27304979
A whole-space transform formula of cylindrical wave functions for scattering problems
NASA Astrophysics Data System (ADS)
Yuan, Xiaoming
2014-03-01
The theory of elastic wave scattering is a fundamental concept in the study of elastic dynamics and wave motion, and the wave function expansion technique has been widely used in many subjects. To supply the essential tools for solving wave scattering problems induced by an eccentric source or multi-sources as well as multi-scatters, a whole-space transform formula of cylindrical wave functions is presented and its applicability to some simple cases is demonstrated in this study. The transforms of wave functions in cylindrical coordinates can be classified into two basic types: interior transform and exterior transform, and the existing Graf's addition theorem is only suitable for the former. By performing a new replacement between the two coordinates, the exterior transform formula is first deduced. It is then combined with Graf's addition theorem to establish a whole-space transform formula. By using the whole-space transform formula, the scattering solutions by the sources outside and inside a cylindrical cavity are constructed as examples of its application. The effectiveness and advantages of the whole-space transform formula is illustrated by comparison with the approximate model based on a large cycle method. The whole-space transform formula presented herein can be used to perform the transform between two different cylindrical coordinates in the whole space. In addition, its concept and principle are universal and can be further extended to establish the coordinate transform formula of wave functions in other coordinate systems.
Yücel, Meryem A.; Selb, Juliette; Aasted, Christopher M.; Lin, Pei-Yi; Borsook, David; Becerra, Lino; Boas, David A.
2016-01-01
Analysis of cerebral hemodynamics reveals a wide spectrum of oscillations ranging from 0.0095 to 2 Hz. While most of these oscillations can be filtered out during analysis of functional near-infrared spectroscopy (fNIRS) signals when estimating stimulus evoked hemodynamic responses, oscillations around 0.1 Hz are an exception. This is due to the fact that they share a common spectral range with typical stimulus evoked hemodynamic responses from the brain. Here we investigate the effect of hemodynamic oscillations around 0.1 Hz on the estimation of hemodynamic response functions from fNIRS data. Our results show that for an expected response of ~1 µM in oxygenated hemoglobin concentration (HbO), Mayer wave oscillations with an amplitude > ~1 µM at 0.1 Hz reduce the accuracy of the estimated response as quantified by a 3 fold increase in the mean squared error and decrease in correlation (R2 below 0.78) when compared to the true HRF. These results indicate that the amplitude of oscillations at 0.1 Hz can serve as an objective metric of the expected HRF estimation accuracy. In addition, we investigated the effect of short separation regression on the recovered HRF, and found that this improves the recovered HRF when large amplitude 0.1 Hz oscillations are present in fNIRS data. We suspect that the development of other filtering strategies may provide even further improvement. PMID:27570699
Yücel, Meryem A; Selb, Juliette; Aasted, Christopher M; Lin, Pei-Yi; Borsook, David; Becerra, Lino; Boas, David A
2016-08-01
Analysis of cerebral hemodynamics reveals a wide spectrum of oscillations ranging from 0.0095 to 2 Hz. While most of these oscillations can be filtered out during analysis of functional near-infrared spectroscopy (fNIRS) signals when estimating stimulus evoked hemodynamic responses, oscillations around 0.1 Hz are an exception. This is due to the fact that they share a common spectral range with typical stimulus evoked hemodynamic responses from the brain. Here we investigate the effect of hemodynamic oscillations around 0.1 Hz on the estimation of hemodynamic response functions from fNIRS data. Our results show that for an expected response of ~1 µM in oxygenated hemoglobin concentration (HbO), Mayer wave oscillations with an amplitude > ~1 µM at 0.1 Hz reduce the accuracy of the estimated response as quantified by a 3 fold increase in the mean squared error and decrease in correlation (R(2) below 0.78) when compared to the true HRF. These results indicate that the amplitude of oscillations at 0.1 Hz can serve as an objective metric of the expected HRF estimation accuracy. In addition, we investigated the effect of short separation regression on the recovered HRF, and found that this improves the recovered HRF when large amplitude 0.1 Hz oscillations are present in fNIRS data. We suspect that the development of other filtering strategies may provide even further improvement. PMID:27570699
Chiral Restoration in a Nuclear Medium ---Probed by S-Wave Pion Dynamics---
NASA Astrophysics Data System (ADS)
Kienle, P.
Using 500 MeV (d,^3He π^-) pion transfer reactions in recoil free kinematics, pionic 1s-states were populated in the ^{115,119,123}Sn isotopes and their binding energies and widths determined by precision missing mass spectroscopy. Using these data and corresponding ones from iso-scalar light nuclei nuclei, ^{16}O, ^{20}Ne and ^{28}Si, we determined the pion nucleus s-wave strength parameters, b_0, b_1, Re B_0, and Im B_0. By comparison of the iso-vector pion nucleon strength, determined from pionic hydrogen X-ray spectroscopy b_1^{free}, with the b_1 in a nuclear medium scaled to the density ρ(0), we deduced a scaling factor, the square of the pion decay constant in the vacuum and in nuclear medium, as R = b_1^{free} / b_1 = f^2_{π}(ρ_0)/f^2_{π} = 0.64. Thus from the observed increase of the pion s-wave iso-vector strength in a nuclear medium a reduction of f^2_{π}, the order parameter of chiral symme try breaking, is indicated in accordance with theoretical expectations. This finding is supported by recent π^+ and π^- scattering experiments. A short outlook is given on a future program at RIBF in RIKEN for precision studies of deeply bound 1s-states in heavy nuclei.
SAID Partial Wave Analyses from CNS DAC (Center for Nuclear Studies Data Analysis Center)
George Washington University (GW) has one of the largest university-based nuclear-physics groups in the nation. Many of the current and future projects are geared to Thomas Jefferson National Accelerator Facility (JLab) at Newport News, VA. JLab is the world's premier electron accelerator for nuclear physics, and GW is one of the charter members of the governing body of JLab, the Southeastern Universities Research Association (SURA). The George Washington Data Analysis Center (DAC) was created in 1998 by an agreement among the Department of Energy, Jefferson Lab, and the GW Center for Nuclear Studies.The activities of the DAC fall into four distinct categories: 1) Performing partial-wave analyses of fundamental two- and three-body reactions; 2) Maintenance of databases associated with these reactions; 3) Development of software to disseminate DAC results (as well as the results of competing model-independent analyses and potential approaches); and 4) Phenomenological and theoretical investigations which bridge the gap between theory and experiment; in particular, the extraction of N* and D * hadronic and electromagnetic couplings. Partial Wave Analyses (and the associated databases) available at GW are: Pion-Nucleon, Kaon-Nucleon, Nucleon-Nucleon, Pion Photoproduction, Pion Electroproduction, Kaon Photoproduction, Eta Photoproduction, Eta-Prime Photoproduction, Pion-Deuteron (elastic), and Pion-Deuteron to Proton+Proton. [Taken from http://www.gwu.edu/~ndl/dac.htm">http://www.gwu.edu/~ndl/dac.htm
Surface-wave generation by underground nuclear explosions releasing tectonic strain
Patton, H.J.
1980-11-03
Seismic surface-wave generation by underground nuclear explosions releasing tectonic strain is studied through a series of synthetic radiation-pattern calculations based on the earthquake-trigger model. From amplitude and phase radiation patterns for 20-s Rayleigh waves, inferences are made about effects on surface-wave magnitude, M/sub s/, and waveform character. The focus of this study is a comparison between two mechanisms of tectonic strain release: strike-slip motion on vertical faults and thrust motion on 45/sup 0/ dipping faults. The results of our calculations show that Rayleigh-wave amplitudes of the dip-slip model at F values between 0.75 and 1.5 are significantly lower than amplitudes of the strike-slip model or of the explosion source alone. This effect translates into M/sub s/ values about 0.5 units lower than M/sub s/ of the explosion alone. Waveform polarity reversals occur in two of four azimuthal quadrants for the strike-slip model and in all azimuths of the dip-slip-thrust model for F values above about 3. A cursory examination of waveforms from presumed explosions in eastern Kazakhstan suggests that releases of tectonic strain are accompanying the detonation of many of these explosions. Qualitatively, the observations seem to favor the dip-slip-thrust model, which, in the case of a few explosions, must have F values above 3.
A study on pseudo interface wave technique for CRDM weld defects in nuclear power plants
Lee, Jaesun E-mail: jpp@pusan.ac.kr; Park, Junpil E-mail: jpp@pusan.ac.kr; Cho, Younho; Huh, Hyung E-mail: dokim@kaeri.re.kr; Park, Keun-Bae E-mail: dokim@kaeri.re.kr; Kim, Dong-Ok E-mail: dokim@kaeri.re.kr
2015-03-31
The nuclear power plant inspection is very important for the safety issue. However due to some radiation and geometric problems, the detection of CRDM(Control Rod Drive Mechanism) can be very difficult by using conventional Ultrasonic Testing method. Also the shrink fit boundary condition can also be an obstacle for the inspection in this paper, instead of conventional Ultrasonic Testing, guided wave was used for the detection of some complicated structures. The CRDM nozzle was installed in reactor head with perfect shrink fit condition by using stainless steel. The wave amplitude distribution on the circumferential direction was calculated with various boundary conditions and the experimental result shows a possibility of the defect detection on J-groove weld.
A study on pseudo interface wave technique for CRDM weld defects in nuclear power plants
NASA Astrophysics Data System (ADS)
Lee, Jaesun; Park, Junpil; Cho, Younho; Huh, Hyung; Park, Keun-Bae; Kim, Dong-Ok
2015-03-01
The nuclear power plant inspection is very important for the safety issue. However due to some radiation and geometric problems, the detection of CRDM(Control Rod Drive Mechanism) can be very difficult by using conventional Ultrasonic Testing method. Also the shrink fit boundary condition can also be an obstacle for the inspection in this paper, instead of conventional Ultrasonic Testing, guided wave was used for the detection of some complicated structures. The CRDM nozzle was installed in reactor head with perfect shrink fit condition by using stainless steel. The wave amplitude distribution on the circumferential direction was calculated with various boundary conditions and the experimental result shows a possibility of the defect detection on J-groove weld.
NASA Astrophysics Data System (ADS)
Bruntz, R. J.; Paxton, L. J.; Miller, E. S.; Bust, G. S.; Mayr, H. G.
2015-12-01
The Transfer Function Model (TFM) has been used in numerous studies to simulate gravity waves. In the TFM, the time dependence is formulated in terms of frequencies, and the horizontal wave pattern on the globe is formulated in terms of vector spherical harmonics. For a wide range of frequencies, the equations of mass, energy and momentum conservation are solved to compile a transfer function. The transfer function can then be easily combined with a time-dependent source whose spatial extent is also expressed in spherical harmonics, to produce a global atmospheric response, including gravity waves. This approach has significant benefits in that the solution is grid-independent (without any inherent limits on resolution), and the solutions do not suffer from singularities at the poles. We will show results from our simulations that couple the output of the TFM to an ionospheric model, to predict traveling ionospheric disturbances (TIDs) driven by the simulated gravity waves.
The effects of extracorporeal shock wave therapy on frozen shoulder patients’ pain and functions
Park, Chan; Lee, Sangyong; Yi, Chae-Woo; Lee, Kwansub
2015-01-01
[Purpose] The present study was conducted to examine the effects of extracorporeal shock wave therapy on frozen shoulder patients’ pain and functions. [Subjects] In the present study, 30 frozen shoulder patients were divided into two groups: an extracorporeal shock wave therapy group of 15 patients and a conservative physical therapy group of 15 patients. [Methods] Two times per week for six weeks, the extracorporeal shock wave therapy group underwent extracorporeal shock wave therapy, and the conservative physical therapy group underwent general physical therapy. Visual analog scales were used to measure frozen shoulder patients’ pain, and patient-specific functional scales were used to evaluate the degree of functional disorders. [Results] In intra-group comparisons, the two groups showed significant decreases in terms of visual analog scales and patient-specific functional scales, although the extracorporeal shock wave therapy group showed significantly lower scores than the conservative physical therapy group. [Conclusion] Extracorporeal shock wave therapy is considered an effective intervention for improving frozen shoulder patients’ pain and functions. PMID:26834326
Sun, Z.; Barnett, R.N.; Lester, W.A. Jr. )
1992-02-01
A wave function constructed as a product of a four-determinant function and a symmetric correlation function is employed in Monte Carlo computations of the ground-state energy of Li{sub 2} at {ital R}{sub {ital e}} = 5.05 Bohrs. Wave function parameters are determined by a fixed-sample minimization of deviations of the local energy. Although the variational Monte Carlo energy for this function lies, as expected, below that of a similar wave function constructed with a single determinant, the four-determinant function/correlation function wave function gives no improvement in quantum Monte Carlo energy. However, the unoptimized four-determinant function/correlation function wave function does yield an energy in excellent agreement with the estimated exact result. The poorer energy of the optimized function is caused by degradation of the nodal structure during parameter optimization.
Relativistic spectral function of nucleons in hot nuclear matter
NASA Astrophysics Data System (ADS)
Ghosh, Sabyasachi; Sarkar, Sourav; Mallik, S.
2010-10-01
We present a simple calculation of the nucleon self-energy in nuclear matter at finite temperature in a relativistic framework, using the real-time thermal field theory. The imaginary parts of one-loop graphs are identified with discontinuities across the unitary and the Landau cuts. We find that in general both the cuts contribute significantly to the spectral function in the region of (virtual) nucleon mass usually considered, even though the unitary cut is ignored in the literature. Furthermore, our relativistic spectral function differs from the one in nonrelativistic approximation, used in some earlier calculations.
Snieder, Roel
2004-04-01
The Green's function of waves that propagate between two receivers can be found by cross-correlating multiply scattered waves recorded at these receivers. This technique obviates the need for a source at one of these locations, and is therefore called "passive imaging." This principle has been explained by assuming that the normal modes of the system are uncorrelated and that all carry the same amount of energy (equipartitioning). Here I present an alternative derivation of passive imaging of the ballistic wave that is not based on normal modes. The derivation is valid for scalar waves in three dimensions, and for elastic surface waves. Passive imaging of the ballistic wave is based on the destructive interference of waves radiated from scatterers away from the receiver line, and the constructive interference of waves radiated from secondary sources near the receiver line. The derivation presented here shows that the global requirement of the equipartitioning of normal modes can be relaxed to the local requirement that the scattered waves propagate on average isotropically near the receivers. PMID:15169121