Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

AIP conference proceedings

Nuclear shell model frontiers

T. Papenbrock

Published Jan 1, 2004• 0 citations
Publisher

Abstract

I present two recent advances in the nuclear shell model. The first concerns the selection of the most relevant basis states out of the vast number of available configurations. Here, the density matrix renormalization group (DMRG) and the wave function factorization are two approaches that approximate low‐lying states. The second part deals with a puzzle of the shell model itself and addresses the preponderance of spin‐0 ground states in shell models with random two‐body interactions.

DOI
10.1063/1.1805917

Related papers

Density matrix renormalization group and wavefunction factorization for nuclei

T. Papenbrock, David J. Dean

We employ the density matrix renormalization group (DMRG) and the wavefunction factorization method for the numerical solution of large-scale nuclear structure problems. The DMRG exhibits an improved convergence for problems with realistic interactions due to the implementation of the finite algorithm. The wavefunction factorization of fpg -shell nuclei yields rapidly converging approximations that are at the present frontier for large-scale shell-model calculations.

arXiv:nucl-th/0412112•Journal of Physics G Nuclear and Particle Physics•Jul 12, 2005•34 citations

Density matrix renormalization group and the nuclear shell model

Stuart Pittel, Nicolae Sandulescu

We describe the use of the density matrix renormalization group method as a means of approximately solving large-scale nuclear shell-model problems. We focus on an angular-momentum-conserving variant of the method and report test results for the nucleus $^{48}\mathrm{Cr}$. The calculation is able to reproduce both the ground-state energy and the energy of the first excited state, by diagonalizing matrices much smaller than those of the full shell model.

arXiv:nucl-th/0601044•Physical Review C•Jan 17, 2006•34 citations

Density matrix renormalization group and wave function factorization for nuclei(DMRG and (continuum) shell model YITP Workshop on New Developments in Nuclear Self-Consistent Mean-Field Theories (MF05))

T. Papenbrock

素粒子論研究•Nov 20, 2005•0 citations

Density matrix renormalization group method and large-scale nuclear shell-model calculations

J. Dukelsky, Stuart Pittel, S. S. Dimitrova +1 more

The particle-hole density matrix renormalization group $(p\ensuremath{-}h$ DMRG) method is discussed as a possible new approach to large-scale nuclear shell-model calculations. Following a general description of the method, we apply it to a class of problems involving many identical nucleons constrained to move in a single large j-shell and to interact via a pairing plus quadrupole interaction. A single-particle term that splits the shell into degenerate doublets is included so as to accommodate the physics of a Fermi surface in the problem. We apply the $p\ensuremath{-}h$ DMRG method to this test problem for two j values, one for which the shell model can be solved exactly and one for which the size of the Hamiltonian is much too large for exact treatment. In the former case, the method is able to reproduce the exact results for the ground state energy, the energies of low-lying excited states, and other observables with extreme precision. In the latter case, the results exhibit rapid exponential convergence, suggesting the great promise of this new methodology even for more realistic nuclear systems. We also compare the results of the test calculations with those from Hartree-Fock-Bogoliubov approximation and address several other questions about the $p\ensuremath{-}h$ DMRG method of relevance to its usefulness when treating more realistic nuclear systems.

arXiv:nucl-th/0202048•Physical Review C•May 9, 2002•44 citations

The Density Matrix Renormalization Group and the Shell Model

Stuart Pittel, B Thakur

We summarize our recent efforts to develop the Density Matrix Renormalization Group (DMRG) method into a practical truncation strategy for large-scale nuclear shell model calculations. Following an overview of the essential features of the DMRG, we discuss the changes we have implemented for its use in nuclei. In particular, we have found it useful to develop an angular-momentum conserving variant of the method (the JDMRG). We then summarize the principal results we have obtained to date, first reporting test results for $^{48}$Cr and then more recent test results for $^{56}$Ni. In both cases we consider nucleons limited to the 2p-1f shell. While both calculations produce a high level of agreement with the exact shell model results, the fraction of the complete space required to achieve this high level of agreement is found to go down rapidly as the size of the full space grows.

arXiv:0904.2345•Apr 15, 2009•0 citations

New approach to large-scale nuclear structure calculations

J. Dukelsky, Stuart Pittel

A new approach to large-scale nuclear structure calculations, based on the density matrix renormalization group (DMRG), is described. The method is tested in the context of a problem involving many identical nucleons constrained to move in a single large-$j$ shell and interacting via a pairing plus quadrupole interaction. In cases in which exact diagonalization of the Hamiltonian is possible, the method is able to reproduce the exact results for the ground-state energy and the energies of low-lying excited states with extreme precision. Results are also presented for a model problem in which exact solution is not feasible.

arXiv:nucl-th/0101048•Physical Review C•May 2, 2001•27 citations
I present two recent advances in the nuclear shell model. The first concerns the selection of the most relevant basis states out of the vast number of available configurations. Here, the density matrix renormalization group (DMRG) and the wave function factorization are two approaches that approximate low‐lying states. The second part deals with a puzzle of the shell model itself and addresses the preponderance of spin‐0 ground states in shell models with random two‐body interactions.
We describe the use of the density matrix renormalization group method as a means of approximately solving large-scale nuclear shell-model problems. We focus on an angular-momentum-conserving variant of the method and report test results for the nucleus 48Cr^{48}\mathrm{Cr}48Cr. The calculation is able to reproduce both the ground-state energy and the energy of the first excited state, by diagonalizing matrices much smaller than those of the full shell model.
The particle-hole density matrix renormalization group $(p\ensuremath{-}h$ DMRG) method is discussed as a possible new approach to large-scale nuclear shell-model calculations. Following a general description of the method, we apply it to a class of problems involving many identical nucleons constrained to move in a single large j-shell and to interact via a pairing plus quadrupole interaction. A single-particle term that splits the shell into degenerate doublets is included so as to accommodate the physics of a Fermi surface in the problem. We apply the $p\ensuremath{-}h$ DMRG method to this test problem for two j values, one for which the shell model can be solved exactly and one for which the size of the Hamiltonian is much too large for exact treatment. In the former case, the method is able to reproduce the exact results for the ground state energy, the energies of low-lying excited states, and other observables with extreme precision. In the latter case, the results exhibit rapid exponential convergence, suggesting the great promise of this new methodology even for more realistic nuclear systems. We also compare the results of the test calculations with those from Hartree-Fock-Bogoliubov approximation and address several other questions about the $p\ensuremath{-}h$ DMRG method of relevance to its usefulness when treating more realistic nuclear systems.
We summarize our recent efforts to develop the Density Matrix Renormalization Group (DMRG) method into a practical truncation strategy for large-scale nuclear shell model calculations. Following an overview of the essential features of the DMRG, we discuss the changes we have implemented for its use in nuclei. In particular, we have found it useful to develop an angular-momentum conserving variant of the method (the JDMRG). We then summarize the principal results we have obtained to date, first reporting test results for 48^{48}48Cr and then more recent test results for 56^{56}56Ni. In both cases we consider nucleons limited to the 2p-1f shell. While both calculations produce a high level of agreement with the exact shell model results, the fraction of the complete space required to achieve this high level of agreement is found to go down rapidly as the size of the full space grows.
A new approach to large-scale nuclear structure calculations, based on the density matrix renormalization group (DMRG), is described. The method is tested in the context of a problem involving many identical nucleons constrained to move in a single large-jjj shell and interacting via a pairing plus quadrupole interaction. In cases in which exact diagonalization of the Hamiltonian is possible, the method is able to reproduce the exact results for the ground-state energy and the energies of low-lying excited states with extreme precision. Results are also presented for a model problem in which exact solution is not feasible.