GREENS FUNCTION PERTURBATION TECHNIQUE FOR KONDO SYSTEM .2. APPLICATION OF PERTURBATION THEORY . DERIVATION OF SUHLS EQUATION

With the aid of a linked diagram expansion for the one electron scattering matrix of the Kondo system the singular log |ω-contributions are calculated up to forth order perturbation theory. Infinite order perturbation theory is carried out for a special class of generalized scattering matrix diagrams. The basic equation of Suhl's dispersion theory is derived under the restriction on one-particle intermediate states. From perturbation theory it is shown that the validity of Suhl's equation is restricted in the sense that it reproduces only the highest order logarithmic singularities exactly. © 1968 Springer-Verlag.