Markov form of the nonequilibrium statistical operator for systems with weak interaction

The formalism of the nonequilibrium statistical operator for weakly interacting systems with closed set of basic operators is shown to admit the reduction to the marcovian form. To prove it a method making it possible to obtain the nonequilibrium statistical operator in the form of the marcovian expansion over weak interaction is formulated. It is essential that this expansion is obtained by means of the rearranging the nonequilibrium statistical operator perturbation theory without any assumptions about the marcovian character of the process. Hence it takes completely into account the “memory effects”.