arXiv:cond-mat/9410046·v2·cond-mat

Does Quantum Chaos Explain Quantum Statistical Mechanics?

Mark Srednicki

Abstract

If a many-body quantum system approaches thermal equilibrium from a generic initial state, then the expectation value $⟨ ψ (t) ∣ A_{i} ∣ ψ (t)⟩$ , where $∣ ψ (t)⟩$ is the system's state vector and $A_{i}$ is an experimentally accessible observable, should approach a constant value which is independent of the initial state, and equal to a thermal average of $A_{i}$ at an appropriate temperature. We show that this is the case for all simple observables whenever the system is classically chaotic.

Comments: 8 pages in RevTeX 3.0; revised version contains an improved discussion of quantum chaos more accessible to nonspecialists