Eikonal many-fermion Green's functions for disordered systems

Abstract

The eikonal approximation to the Green's function for a fermion in an external potential is evaluated for various time boundary conditions including the finite-temperature case. The one- and two-fermion Green's functions thus obtained are averaged over a Gaussian ensemble of potentials to yield an average density of states and an average conductivity tensor. © 1972 The American Physical Society.