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We perform particle-number projected mean-field study using the recently developed symmetry-projected Hartree-Fock-Bogoliubov (HFB) equations. Realistic calculations have been performed in sd- and fp-shell nuclei using the shell model…

Nuclear Theory · Physics 2015-05-20 I. Maqbool , J. A. Sheikh , P. A. Ganai , P. Ring

Energy spectroscopy is a powerful tool with diverse applications across various disciplines. The advent of programmable digital quantum simulators opens new possibilities for conducting spectroscopy on various models using a single device.…

The density functional theory of nuclear structure provides a many-particle wave function that is useful for static properties, but an extension of the theory is necessary to describe correlation effects or other dynamic properties. Here we…

Nuclear Theory · Physics 2009-11-11 Y. Alhassid , G. F. Bertsch , L. Fang , B. Sabbey

We present the first ab initio construction of valence-space Hamiltonians for medium-mass nuclei based on chiral two- and three-nucleon interactions using the in-medium similarity renormalization group. When applied to the oxygen isotopes,…

Nuclear Theory · Physics 2014-10-08 S. K. Bogner , H. Hergert , J. D. Holt , A. Schwenk , S. Binder , A. Calci , J. Langhammer , R. Roth

An extrapolation method in shell model calculations with deformed basis is presented, which uses a scaling property of energy and energy variance for a series of systematically approximated wave functions to the true one. Such approximated…

Nuclear Theory · Physics 2009-11-10 Takahiro Mizusaki

The Hartree-Fock approximation for bosons employs variational wave functions that are a combination of permanents. These are bosonic counterpart of the fermionic Slater determinants, but with the significant distinction that the…

Quantum Gases · Physics 2025-03-03 B. R. Que , J. M. Zhang , H. F. Song , Y. Liu

The coordinate space formulation of the Hartree-Fock-Bogoliubov (HFB) method enables self-consistent treatment of mean-field and pairing in weakly bound systems whose properties are affected by the particle continuum space. Of particular…

Nuclear Theory · Physics 2008-12-24 J. C. Pei , M. V. Stoitsov , G. I. Fann , W. Nazarewicz , N. Schunck , F. R. Xu

The spectral and statistical properties of nuclei $^{46}$V and $^{48}$Cr are studied in the framework of nuclear shell model. A microscopical effective Hamiltonian derived from the CD-Bonn \textit{NN} potential is employed. The calculations…

Nuclear Theory · Physics 2007-05-23 C. Qi , F. R. Xu

In electronic structure theory, variational methods offer a valuable paradigm for approximating electronic ground states. However, for historical reasons, this principle is mostly restricted to model chemistries in pre-defined fixed basis…

Quantum Physics · Physics 2025-11-17 Fabian Langkabel , Stefan Knecht , Jakob S. Kottmann

The variational multiparticle-multihole configuration mixing approach (MPMH) to nuclei has been proposed about a decade ago. While the first applications followed rapidly, the implementation of the full formalism of this method has only…

Nuclear Theory · Physics 2017-04-26 C. Robin , N. Pillet , M. Dupuis , J. Le Bloas , D. Peña Arteaga , J. -F. Berger

A method for beyond-mean-field calculations based on an energy density functional is described. The main idea is to map the energy surface for the nuclear quadrupole deformation, obtained from an energy density functional at the mean-field…

Nuclear Theory · Physics 2022-12-16 J. Ljungberg , J. Boström , B. G. Carlsson , A. Idini , J. Rotureau

The numerical solution of the recently formulated number-projected Hartree-Fock-Bogoliubov equations is studied in an exactly soluble cranked-deformed shell model Hamiltonian. It is found that the solution of these number-projected…

Nuclear Theory · Physics 2009-11-06 J. A. Sheikh , E. Lopes , P. Ring

A new theoretical approach is presented that combines the Hartree-Fock variational scheme with the exact solution of the pairing problem in the finite orbital space. Using this formulation in the sd-space as an example, we show that the…

Nuclear Theory · Physics 2008-11-26 R. A. Sen'kov , G. F. Bertsch , B. A. Brown , Y. L. Luo , V. G. Zelevinsky

The current work plans to study the accuracy due to FD approximation to the 3D nuclear HFB problem. By (1) taking the wave functions solved in harmonic oscillator (HO) basis, (2) representing the HFB problem in coordinate space using FD…

Nuclear Theory · Physics 2018-08-08 Yue Shi

For a hydrogen atom subject to a constant magnetic field, we report a numerical realization of the two-dimensional Non-Linearization Procedure (NLP) to estimate the accuracy of the variational energy associated with a given trial function.…

Atomic Physics · Physics 2024-07-31 J. C. del Valle

We apply the auxiliary-field Monte Carlo approach to the nuclear shell model in the 1s-0d configuration space. The Hamiltonian was chosen to have isovector pairing and isoscalar multipole-multipole interactions, and the calculations were…

Nuclear Theory · Physics 2008-11-26 W. E. Ormand , D. J. Dean , C. W. Johnson , G. H. Lang , S. E. Koonin

The advent of nucleon-nucleon potentials derived from chiral perturbation theory, as well as the so-called V-low-k approach to the renormalization of the strong short-range repulsion contained in the potentials, have brought renewed…

Nuclear Theory · Physics 2015-05-27 L. Coraggio , A. Covello , A. Gargano , N. Itaco , T. T. S. Kuo

We assess the accuracy of finite-temperature mean-field theory using as a standard the Hamiltonian and model space of the shell model Monte Carlo calculations. Two examples are considered: the nucleus $^{162}$Dy, representing a heavy…

Nuclear Theory · Physics 2016-05-04 Y. Alhassid , G. F. Bertsch , C. N. Gilbreth , H. Nakada

Recently, the numerical solution of multi-frequency, highly-oscillatory Hamiltonian problems has been attacked by using Hamiltonian Boundary Value Methods (HBVMs) as spectral methods in time. When the problem derives from the space semi-…

Numerical Analysis · Mathematics 2018-08-14 Luigi Brugnano , Felice Iavernaro , Juan I. Montijano , Luis Ràndez

We present an \textit{ab initio} study of nuclear structure in the island of inversion around neutron number $N=20$, using multishell effective Hamiltonians derived from the valence-space in-medium similarity renormalization group approach…

Nuclear Theory · Physics 2025-11-25 X. C. Cao , C. F. Jiao