Construction of a kinetic equation for a quantum dynamical system interacting with a phonon field by the method of ordered operators

The derivation of a general kinetic equation for a quantum dynamical system interacting with a phonon field is considered. The theory is constructed by the method of ordered operators without the use of any approximations. The general theory is illustrated by the example of a quantum harmonic oscillator under the influence of a variable external classical force that is linearly coupled to a thermal bath, i.e., a system of noninteraeting quantum oscillators. A generalized kinetic equation of Hloeh type is derived on the basis of the obtained exact relations after an appropriate approximation procedure for the quantum oscillator.