On the ground state calculation of a many-body system using a self-consistent basis and quasi-Monte Carlo: An application to water hexamer

2013 ◽  
Vol 139 (20) ◽  
pp. 204104 ◽  
Author(s):  
Ionuţ Georgescu ◽  
Svetlana Jitomirskaya ◽  
Vladimir A. Mandelshtam
Keyword(s):  
Monte Carlo ◽  
Ground State ◽  
Body System ◽  
Many Body ◽  
Quasi Monte Carlo ◽  
State Calculation ◽  
Self Consistent ◽  
Consistent Basis

Mesonic and isobar degrees of freedom in the ground state of the nuclear many-body system

1978 ◽  
Vol 18 (5) ◽  
pp. 2416-2429 ◽  
Author(s):  
M. R. Anastasio ◽  
Amand Faessler ◽  
H. Müther ◽  
K. Holinde ◽  
R. Machleidt
Keyword(s):  
Ground State ◽  
Degrees Of Freedom ◽  
Body System ◽  
Many Body

Some Properties of Coupled RPA Equations with Separable Interactions

1997 ◽  
Vol 06 (02) ◽  
pp. 251-258 ◽  
Author(s):  
Hideo Sakamoto
Keyword(s):  
Ground State ◽  
Random Phase Approximation ◽  
Strength Function ◽  
Random Phase ◽  
Transition Strength ◽  
Body System ◽  
Many Body ◽  
Hartree Fock ◽  
Secular Equations ◽  
The Stability

We investigate some properties of coupled eigenvalue equations in the random phase approximation for fundamental modes of motion in a nuclear many-body system undergoing several separable two-body interactions. Based on the Sturm's method, a new algorithm is proposed for solving such coupled secular equations and for testing the stability condition of the Hartree-Fock ground state. A transition strength in general is expressed in a compact form and, in a restricted case, a continuous strength function is constructed by averaging with a Lorentzian distribution function.

scholarly journals Self-consistent effective Hamiltonian theory for fermionic many-body systems

2020 ◽  
pp. 2150019
Author(s):  
Xindong Wang ◽  
Hai-Ping Cheng
Keyword(s):  
Hubbard Model ◽  
Order Parameter ◽  
Cooper Pair ◽  
Effective Hamiltonian ◽  
Two Dimensional ◽  
Body System ◽  
Many Body ◽  
Hamiltonian Theory ◽  
Self Consistent ◽  
Many Body Systems

Using a separable many-body variational wavefunction, we formulate a self-consistent effective Hamiltonian theory for fermionic many-body system. The theory is applied to the two-dimensional (2D) Hubbard model as an example to demonstrate its capability and computational effectiveness. Most remarkably for the Hubbard model in 2D, a highly unconventional quadruple-fermion non-Cooper pair order parameter is discovered.

scholarly journals A MICROSCOPIC LOOK AT LIQUID HELIUM: THE 3He IMPURITY CASE

2001 ◽  
Vol 15 (10n11) ◽  
pp. 1575-1590
Author(s):  
A. POLLS ◽  
A. FABROCINI
Keyword(s):  
Monte Carlo ◽  
Liquid Helium ◽  
Basis Function ◽  
Ground State ◽  
Interatomic Interaction ◽  
Many Body ◽  
Excitation Energies ◽  
Momentum Range ◽  
Particle Correlation ◽  
Correlation Operator

The description of the properties of liquid Helium is a challenge for any microscopic many-body theory. In this context, we study the ground state and the excitation spectrum of one 3 He impurity in liquid 4 He at T=0 with the aim of illustrating the power of the correlated basis function formalism in describing heavily correlated systems. The strong interatomic interaction and the large density require the theory to be pushed to a high degree of sophistication. A many-body correlation operator containing explicit two- and three-particle correlation functions is needed to obtain a realistic ground state wave function, whereas a perturbative expansion including up to two phonon correlated states must be enforced to study the impurity excitation energies. The theory describes accurately the experimental spectrum along all the available momentum range. As empirically shown by the experiments, a marked deviation from the quadratic Landau-Pomeranchuck behavior is found and the momentum dependent effective mass of the impurity increases of ~50% at q~1.7 Å-1 with respect to its q=0 value. Although the main emphasis is given to the correlated basis function theory, we present also comparisons with other methods, as diffusion Monte Carlo, variational Monte Carlo with shadow wave functions and time dependent correlations.

The Δ(1236) probability in the ground state of the nuclear many-body system

1979 ◽  
Vol 322 (2-3) ◽  
pp. 369-381 ◽  
Author(s):  
M.R. Anastasio ◽  
Amand Faessler ◽  
H. Müther ◽  
K. Holinde ◽  
R. Machleidt
Keyword(s):  
Ground State ◽  
Body System ◽  
Many Body
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