Korrelations- und Nachwirkungsfunktionen in Quantensystemen mit irreversibler Dynamik

The well known analogy between the classical distribution function and the quantum mechanical density operator is extended to the cases of joint and conditional probability-distributions. Thus one is led to a generalized definition of correlation and response-functions in quantum systems. The generalization becomes essential if irreversible dynamical laws such as the Wangsness-Bloch equation are considered.