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Related papers: Microscopic calculations of nuclear level densitie…

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In physics, it is sometimes desirable to compute the so-called \emph{Density Of States} (DOS), also known as the \emph{spectral density}, of a real symmetric matrix $A$. The spectral density can be viewed as a probability density…

Numerical Analysis · Mathematics 2014-10-07 Lin Lin , Yousef Saad , Chao Yang

The configuration-interaction shell model approach provides an attractive framework for the calculation of nuclear level densities in the presence of correlations, but the large dimensionality of the model space has hindered its application…

Nuclear Theory · Physics 2016-01-05 Y. Alhassid , G. F. Bertsch , C. N. Gilbreth , H. Nakada , C. Özen

We propose a thick-restart block Lanczos method, which is an extension of the thick-restart Lanczos method with the block algorithm, as an eigensolver of the large-scale shell-model calculations. This method has two advantages over the…

Nuclear Theory · Physics 2019-10-02 Noritaka Shimizu , Takahiro Mizusaki , Yutaka Utsuno , Yusuke Tsunoda

In this work, the reliability of the Landau expression for the nuclear level density calculations is tested, for the first-time, to describe nuclear level densities of some light, intermediate mass and heavy nuclei at excitations…

Nuclear Theory · Physics 2016-06-09 A. Elmas , H. Ahmadov , B. Gonul

The level density is among the most important statistical nuclear properties. It appears in Fermi's golden rule for transition rates and is an important input to the Hauser-Feshbach theory of compound nucleus reactions. We discuss empirical…

Nuclear Theory · Physics 2022-01-05 Y. Alhassid

Nucleosynthesis calculations require nuclear level densities for hundreds or even thousands of nuclides. Ideally one would like to constrain these level densities by microscopically motivated yet computationally cheap models. A statistical…

Nuclear Theory · Physics 2007-05-23 Jameel-Un Nabi , Calvin W. Johnson , W. Erich Ormand

Ground state energies and on-site density-density correlations are calculated for the 1-D Hubbard model using a linear combination of the Hubbard projection operators. The mean-field coefficients in the resulting linearized Equations of…

Condensed Matter · Physics 2009-10-22 J. C. Hicks , J. Tinka Gammel

We introduce a novel method to obtain level densities in large-scale shell-model calculations. Our method is a stochastic estimation of eigenvalue count based on a shifted Krylov-subspace method, which enables us to obtain level densities…

We describe the application of the locally-self-consistent-multiple-scattering (LSMS)[1] method to amorphous alloys. The LSMS algorithm is optimized for the Intel XP/S-150, a multiple-instruction-multiple-data parallel computer with 1024…

Condensed Matter · Physics 2009-10-28 J. C. Swihart , D. M. C. Nicholson , G. M. Stocks , Y. Wang , W. A. Shelton , H. Yang

The distribution of the eigenvalues of a Hermitian matrix (or of a Hermitian matrix pencil) reveals important features of the underlying problem, whether a Hamiltonian system in physics, or a social network in behavioral sciences. However,…

Numerical Analysis · Mathematics 2017-06-22 Yuanzhe Xi , Ruipeng Li , Yousef Saad

The shell model Monte Carlo (SMMC) approach allows for the microscopic calculation of statistical and collective properties of heavy nuclei using the framework of the configuration-interaction shell model in very large model spaces. We…

Nuclear Theory · Physics 2015-06-23 C. Özen , Y. Alhassid , H. Nakada

The microscopic calculation of nuclear level densities in the presence of correlations is a difficult many-body problem. The shell model Monte Carlo method provides a powerful technique to carry out such calculations using the framework of…

Nuclear Theory · Physics 2013-05-27 Y. Alhassid , C. Özen , H. Nakada

Relativistic energy density functionals (EDF) have become a standard tool for nuclear structure calculations, providing a complete and accurate, global description of nuclear ground states and collective excitations. Guided by the medium…

Nuclear Theory · Physics 2015-05-27 Tamara Niksic , Dario Vretenar , Peter Ring

A particle-number reprojection method is applied in the framework of the shell model Monte Carlo approach to calculate level densities for a family of nuclei using Monte Carlo sampling for a single nucleus. In particular we can also…

Nuclear Theory · Physics 2009-11-06 S. Liu , Y. Alhassid , H. Nakada

A metamodeling for the nucleonic equation of state (EOS), inspired from a Taylor expansion around the saturation density of symmetric nuclear matter, is proposed and parameterized in terms of the empirical parameters. The present knowledge…

Nuclear Theory · Physics 2018-03-07 J. Margueron , R. Hoffmann Casali , F. Gulminelli

In the independent-particle model, the nuclear level density is determined from the neutron and proton single-particle level densities. The single-particle level density for the positive-energy continuum levels is important at high…

Nuclear Theory · Physics 2009-11-10 R. J. Charity , L. G. Sobotka

We construct the equation of state (EOS) in a wide density range for neutron stars using the relativistic mean field theory. The properties of neutron star matter with both uniform and non-uniform distributions are studied consistently. The…

Nuclear Theory · Physics 2009-11-07 H. Shen

The prediction of cross sections for nuclei far off stability is crucial in the field of nuclear astrophysics. In recent calculations the nuclear level density -- as an important ingredient to the statistical model (Hauser-Feshbach) -- has…

Astrophysics · Physics 2016-08-30 T. Rauscher , F. -K. Thielemann , K. -L. Kratz

We present an efficient Monte Carlo algorithm for determining the density of states which is based on the statistics of transition probabilities between states. By measuring the infinite temperature transition probabilities--that is, the…

Soft Condensed Matter · Physics 2009-11-10 M. S. Shell , P. G. Debenedetti , A. Z. Panagiotopoulos

A phenomenological method based on the natural orbital representation is applied to construct the ground state one-body density matrix which describes correctly both density and momentum distributions in $^{4}He$, $^{16}O$ and $^{40}Ca$…