Thermal Field Theory in Non-Equilibrium States

Abstract

Conventional transport theory is not really applicable to non-equilibrium systems which exhibit strong quantum effects. We present two different approaches to overcome this problem. Firstly we point out how transport equations may be derived that incorporate a nontrivial spectral function as a typical quantum effect, and test this approach in a toy model of a strongly interacting degenerate plasma. Secondly we explore a path to include non-equilibrium effects into quantum field theory through momentum mixing transformations in Fock space. Although the two approaches are completely orthogonal, they lead to the same coherent conclusion.

15 pages, latex, 2 figures, also available at ftp://tpri6c.gsi.de/pub/phenning/hny95/ or at http://www.gsi.de/~phenning/tft.html Dedicated to the memory of Hiroomi Umezawa