A new method for decoupling Bogolyubov’s chains for quantum models

The paper describes in detail a method for investigating the effects of dynamical coupling in the energy- and charge-transfer processes with regard to an averaged external field of all the particles of the system. The particles are assumed to take part only in pair correlations which makes possible effective truncation of Bogolubov's chains. It is shown that the method enables effective consideration of temperature and is well suited for most of quantum-mechanical systems where triple correlations of quantum particles are hardly probable. To demonstrate the potentialities of the approach the models by Matsubara, Froehlich and Yukawa are investigated.