TIME EVOLUTION OF A CENTRAL OSCILLATOR IN HEAT BATH DERIVED BY VIRTUE OF THE IWOP TECHNIQUE
Hong-Yi Fan, Xuefen Xu · Modern Physics Letters B · 2006
By virtue of the technique of integration within an ordered product of operators we derive the normally ordered expansion of time evolution operator for the case of a central oscillator immersed in a heat bath composed of a large number of oscillators. The time evolution of the system and heat bath into coherent states is discussed based on energy conservation. As a by-product, the partition function of two coupled oscillators is also calculated in this way.