Many-body theory of degenerate systems
نویسنده
چکیده
The many-body theory of degenerate systems is described in detail. More generally, this theory applies to systems with an initial state that cannot be described by a single Slater determinant. The double-source (or closed-time-path) formalism of nonequilibrium quantum field theory is used to derive an expression for the average value of a product of interacting fields when the initial state is not the vacuum or a Slater determinant. Quantum group techniques are applied to derive the hierarchy of unconnected Green functions and the hierarchy of connected ones.
منابع مشابه
Many-body theory of degenerate systems: A simple example
Christian Brouder Laboratoire de Minéralogie Cristallographie, CNRS UMR 7590, Universités Paris 6 et 7, IPGP, case 115, 4 place Jussieu, 75252 Paris cedex 05, France. (Dated: February 2, 2008) The hierarchy of Green functions for (quasi)degenerate systems, presented in cond-mat/0308058, is calculated in detail for the case of a system with closed shells plus a single electron in a two-fold dege...
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