The approach to thermal equilibrium in quantized chaotic systems

摘要: We consider many-body quantum systems that exhibit chaos, in the sense observables of interest act on energy eigenstates like banded random matrices. study time-dependent expectation values these observables, assuming system is a definite (but arbitrary) pure state. induce probability distribution for by treating zero time as uniformly distributed variable. show explicitly if an observable has non-equilibrium value at some particular moment, then it overwhelmingly likely to move towards equilibrium, both forwards and backwards time. For deviations from equilibrium are not much larger than typical or thermal fluctuation, we find dependence given Kubo correlation function, agreement with Onsager's postulate. These results independent details system's