Symmetric nuclear matter is studied within the conserving, self-consistent T -matrix approximation. This approach involves off-shell propagation of nucleons in the ladder diagrams. The binding energy receives contributions from the background part of the spectral function, away form the quasiparticle peak. The Fermi energy at the saturation point fulfills the Hugenholz-Van Hove relation. In com...

We demonstrate that the skeleton of the Fermi surface Sf;σ pertaining to a uniform metallic ground state (corresponding to fermions with spin index σ) is determined by the Hartree-Fock contribution Σ σ (k) to the dynamical self-energy Σσ(k; ε). That is to say, in order for k ∈ Sf;σ it is necessary (but for anisotropic ground states in general not sufficient) that the following equation be satis...

We investigate multiterminal quantum transport through single monocyclic aromatic annulene molecules, and their derivatives, using the nonequilibrium Green function approach within the self-consistent Hartree-Fock approximation. We propose a new device concept, the quantum interference effect transistor, that exploits perfect destructive interference stemming from molecular symmetry and control...

We outline a method for the calculation of nonlinear properties such as dynamic hyperpolarizabilities for self-consistent-field (SCF) wave functions. In this method, twoelectron integrals are only addressed in the evaluation of Fock matrices and Fock matrices with one-index transformed integrals. These matrices are determined directly in terms of integrals evaluated in the atomic orbital basis,...

Recently, the shell model in the complex k-plane (the so-called Gamow Shell Model) has been formulated using a complex Berggren ensemble representing bound single-particle states, single-particle resonances, and non-resonant continuum states. In this framework, we shall discuss binding energies and energy spectra of neutron-rich helium and lithium isotopes. The single-particle basis used is tha...

We compute using a microscopic mean-field theory the structure and the quasiparticle excitation spectrum of a dilute, trapped Bose–Einstein condensate penetrated by an axisymmetric vortex line. The Gross–Pitaevskii equation for the condensate and the coupled Hartree–Fock–Bogoliubov–Popov equations describing the elementary excitations are solved self-consistently using finite-difference methods...

A biorthogonal formulation is applied to the non-Hermite transcorrelated Hamiltonian, which treats a large amount of the dynamic correlation effects implicitly. We introduce biorthogonal canonical orbitals diagonalizing the non-Hermitian Fock operator. We also formulate many-body perturbation theory for the transcorrelated Hamiltonian. The biorthogonal self-consistent field followed by the seco...

In this paper we consider the Hamiltonian of quantum electrodynamics, which describes the system of Dirac fields coupled to quantized radiation fields. We impose ultraviolet cutoffs on the Dirac field and the radiation field, and introduce spatial cutoffs to define the Hamiltonian as a self-adjoint operator on a boson-fermion Fock space. Taking a scaling limit of the Hamiltonian, we derive the ...

In this paper, we propose a generic and systematic approach for study of the electronic structure for atoms or molecules. In particular, we address the issue of single particle states, or orbitals, which should be one of the most important aspects of a quantum many-body theory. We argue that the single-particle Green function provides a most general scheme for generating these single particle s...