Anderson model in thermo field dynamics: Generalized Feynman-diagram method

Abstract

A perturbation theory that allows treatment of a system of self-interacting localized electrons and conduction electrons is constructed through the use of the newly proposed generalized Feynman-diagram method in thermo field dynamics. The Feynman rules for the case of the Anderson model and s-f interaction in the strong Coulomb limit are presented. A simple computational example is presented for the Kondo problem for the sake of illustration.