On Markovian kinetic equations: Zubarev's nonequilibrium statistical operator approach

Generalized Markovian kinetic equations, obtained by the Zubarev method of the nonequilibrium statistical operator NSO, are revised. In a simple example of the spin S = 12 coupled to its surroundings, it is shown that these equations are incorrect because of an inadequate Markovian approximation. A correct procedure of building Markovian equations of motion is constructed. Two different, although equivalent methods, the Davies technique and the Krylov-Bogoliubov-Mitropolsky averaging method, are utilized.