Nonequilibrium entropy and definition of products of generalized functions. II

The construction of nonequilibrium entropy is related to a certain regularization of the von Neumann entropy corresponding to the kinetic stage of evolution. It is shown that in the third approximation of perturbation theory undetermined constants appear in the entropy. In this connection, the construction of the nonequilibrium entropy is related to the question of determining products of generalized functions with coincident singularities in the Bogolyubov–Parasyuk sense.