Peter Schuck

Truncation scheme of time-dependent density-matrix approach

A truncation scheme of the Bogoliubov-Born-Green-Kirkwood-Yvon hierarchy for reduced density matrices, where a three-body density matrix is approximated by the antisymmetrized products of two-body density matrices, is proposed. This truncation scheme is tested for three model Hamiltonians. It is shown that the obtained results are in good agreement with the exact solutions.

Extension of time-dependent Hartree-Fock-Bogoliubov equations

An extension of the time-dependent Hartree-Fock-Bogoliubov theory (ETDHFB) which includes higher-order effects such as screening of the pairing correlation is proposed. ETDHFB is applied to a fermion system trapped in a harmonic potential to test its feasability by comparison with the exact solution. With the use of perturbative expressions for the pairing tensor and the two-body density matrix derived from ETDHFB, the screening effect is investigated for atomic fermion systems and isotopes of tin nuclei. It is found that the screening effect on the pairing correlation is not significant.

The Shell Model

The ICAO SHELL Model is a conceptual framework proposed in ICAO Circular 216-AN31. One practical diagram to illustrate this conceptual model uses blocks to represent the different components of human factors. This building block diagram does not cover the interfaces which are outside human factors (hardware-hardware; hardware-environment; software-hardware) and is only intended as a basic aid to understanding human factors.