The Hartree Approximation, the Collisionless Boltzmann Equation, and the Random Phase Approximation

Our general procedure for describing transport phenomena will be based on approximations in which the g₂(U) that appears in the equation of motion for g(U) is expanded in terms of g(U). The simplest approximation of this nature is the Hartree approximation. (7-1) g 2 ( 12 ; 1 ′ 2 ′ ; U ) = g ( 1 , 1 ′ ; U ) g ( 2 , 2 ′ ; U ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429493218/2723bf93-af84-4d1d-955c-798a77ad6aa2/content/eq319.tif"/>