Projection Techniques in the Theory of Electrical Resistivity

Abstract

A formula for the electrical resistivity expressed in terms of a projection operator is derived and discussed. It is argued that the correct evaluation of the resistivity to the lowest order in the strength of the scattering interaction on the basis of this formula requires, as do other formal expressions, the summation of an infinite number of terms. This re-establishes the standard theory of electrical conductivity, based on the integral transport equation for the distribution function.