Finite expansion of the inverse matrix in the polarization propagator method |
| |
Authors: | Claudio N. Cavasotto |
| |
Affiliation: | (1) Departamento de Física, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Pabellón I, 1428 Buenos Aires, Argentina, AR |
| |
Abstract: | An alternative theoretical approach to the polarization propagator based on a new finite expansion of a finite-dimensional matrix is presented. The general equations for such an expansion are derived and the validity conditions stated. This method is used to accomplish an approximate scheme for the self-energy of the particle–hole propagator within the superoperator formalism. Within this scheme each contribution includes corrections to infinite order in electronic interaction and so describes collective effects in a natural way. Individual contributions can be interpreted as describing the propagation of the interaction through a particular subset of electronic excitations. Comparison with other known approximation levels, such as the random-phase approximation, is also analyzed. Received: 14 February 2000 / Accepted: 18 April 2000 / Published online: 18 August 2000 |
| |
Keywords: | : Polarization propagator – Particle– hole propagator – Self-energy – Inverse matrix |
本文献已被 SpringerLink 等数据库收录! |
|