Role of correlations in the thermalization of quantum systems
  We investigate the equilibration and thermalization properties of quantum systems interacting with a finite dimensional environment. By exploiting the concept of time averaged states, we introduce a completely positive map which allows to describe in a quantitative way the dependence of the equilibrium state on the initial condition. Our results show that the thermalization of quantum systems is favored if the dynamics induces small system-environment correlations, as well as small changes in the environment, as measured by the trace distance. 
A. Smirne, E.-M. Laine, H.-P. Breuer, J. Piilo and B. Vacchini
quant-ph