This chapter presents the Hartree-Fock method with an emphasis on computing the energies of selected closed-shell atoms.

In the mean-field limit the dynamics of a quantum Bose gas is described by a Hartree equation. We present a simple method for proving the convergence of the microscopic quantum dynamics to the Hartree dynamics when the number of particles becomes large and the strength of the two-body potential tends to 0 like the inverse of the particle number. Our method is applicable for a class of singular ...

It is shown that a variational approach with fermionic squeezed states to manyfermion systems such as pairing model is one of useful methods beyond the usual Hartree-Fock-Bogoliubov approximation. A pairing-type quasi-spin squeezed state is constructed and adopted as a trial state in the variational method. By using this state, quantum fluctuations are taken into account. In pairing model, dyna...

We study an extended Lipkin-Meshkov-Glick model that permits a transition to a deformed phase with a broken continuous symmetry. Unlike simpler models, one sees a persistent zero-frequency Goldstone mode past the transition point into the deformed phase. We found that the RPA formula for the correlation energy provides a useful correction to the Hartree-Fock energy when the number of particle N...

In this paper we begin the development of a formalism for the description of high energy neutrino interactions. It is based upon field theory quantized on a null plane. We set up the general formalism as well as some techniques needed to perform phenomenological calculations. We show that the formalism developed by Wolfenstein is recovered at the cost of making two approximations: one has to tr...

In this work, we show that an implementation of Coulomb-attenuated density-functional theory leads to considerably better prospects than hitherto for modeling two-photon absorption cross sections for charge-transfer species. This functional, which corrects for the effect of poor asymptotic dependence of commonly used functionals, essentially brings down the widely different results for larger c...

We investigated self-consistent spin-resolved local-field corrections in a spin-polarized electron gas. The local-field corrections, structure factors, and susceptibility functions form a self-consistent loop. Three different local-field corrections and structure factors each based on the Hartree-Fock structure factor, the Gori-Giorgi–Perdew pair correlation function, and self-consistent calcul...

Isotope dependences of charge radii, i.e., isotope shifts, calculated by the Skyrme Hartree-Fock, relativistic mean-field, and Hartree-Fock calculations are compared against experimental data magic semimagic nuclei. It is found that tensor interaction plays a role in reproducing ``kink'' behavior, irregularity shifts at neutron number, approach. With several models, it kink behavior can be repr...