A modified Green's function determination of the conduction and insulator limit conductivities of the one-dimensional, half-filled band, Hubbard model

A modified Green's function determination of the conduction and insulator limit conductivities of the one-dimensional, half-filled band, Hubbard model is presented in a simplified version to avoid the difficulties which are encountered in some instances in utilizing commutator Green's functions in first order response determinations to external perturbations.