A generating function method for eliminating anomalous diagrams in statistical mechanics

Kaoru Sakamoto, Toshio Aoe

É. A. Arinshtein, Dmitri M Gitman

Vyacheslav I. Yukalov

An alternative approach for treating strongly interacting statistical systems with strongly singular potentials is developed. This approach combines both the advantages of decoupling procedures for Green functions, which eliminate divergences caused by singular potentials, and the advantages of perturbation theory, which is a regular procedure that makes it possible to construct subsequent approximations above the chosen decoupling. The resulting iterative sequence of Green functions generates corresponding sequences of observable quantities. To improve the convergence of the latter sequences a method is suggested based on the renormalization-group ideas. A simple illustration is given.

Ralf Der, Siegfried Fritzsche A, Reinhold Haberlandt

Abstract A diagram expansion is proposed for calculating traces of the kind Tr{Ae−itLB} which are of interest for calculating time correlation functions and expectation values in nonequilibrium statistical mechanics. Arbitrary initial conditions are considered. In the classical limit the diagram expansion of FUJITA is obtained. A systematic method for obtaining quantum corrections including exchange and symmetry effects is proposed.

S. Nakajima

Sergei Vladimirovich Tyablikov