Local Thermal Equilibrium States in Relativistic Quantum Field Theory

Abstract

It is well-known that thermal equilibrium states in quantum statistical mechanics and quantum field theory can be described in a mathematically rigorous manner by means of the so-called Kubo-Martin-Schwinger (KMS) condition, which is based on certain analyticity and periodicity properties of correlation functions. On the other hand, the characterization of non-equilibrium states which only locally have thermal properties still constitutes a challenge in quantum field theory. We discuss a recent proposal for characterization of such states by a generalized KMS condition. The connection of this proposal to a proposal by D. Buchholz, I. Ojima and H.-J. Roos for characterizing local thermal equilibrium states in quantum field theory is discussed.Comment: 14 pp., version as appeared in "Quantum Mathematical Physics", with one reference updated, "Quantum Mathematical Physics", eds. Felix Finster et al. (Proceedings of the conference "Quantum Mathematical Physics - A Bridge between Mathematics and Physics", Regensburg 2014), Birkh\"auser (2016