Generalized equations for the transport coefficients of electrons and phonons

We start with the equations of the generalized kinetic theory of electrons and phonons. The linearization of the kinetic equations is important in view of the calculation of transport coefficients. Based on a suitable ansatz for the perturbation of the distribution functions, a set of integral equations is constructed for the transport coefficients. Two examples of the application of such equations are given: (a) the lattice thermal conduction; (b) the Lorentz approximation for electron transport coefficients