STATISTICAL CORRELATIONS IN THE OSCILLATOR MODEL OF QUANTUM DISSIPATIVE SYSTEMS

We study the problem of the initial conditions for the oscillator mode l of quantum dissipative systems. It is argued that, even in the class ical case, the hypothesis that the environment is in thermal equilibri um implies a statistical correlation between the environment and the c entral system. Analogously to the classical model, we obtain a simple form of initial conditions for the quantum problem that takes into acc ount such a correlation. As a check on the new form of correlated init ial conditions, we study the forced Brownian particle with arbitrary c oloured noise. On the one hand, starting from the correlated initial c onditions, we show that the average position of a wave packet is equal to that of the corresponding classical Brownian particle. On the othe r hand, starting from the initial conditions based on the factorizatio n hypothesis, that implies absence of correlation, nonphysical results are obtained.