ABSTRACT
The microscopic calculation of kinetic coefficients of non-ideal matter defined via linear response functions by different variants of linear response theory is a very complicated problem (see §5) at first because of the non-applicability of perturbation theory (owing to the absence of a small parameter) to calculation of the characteristics of non-ideal systems. As a consequence, the general restrictions to the values of response functions which concern their analytical properties, function ranges etc. have a special meaning. A set of such restrictions is considered in §6.
