How to Formulate Non-Equilibrium Local States in QFT? --General Characterization and Extension to Curved Spacetime--

The essence of a general formulation to accommodate non-equilibrium local states in relativistic quantum field theory is explained from the viewpoint of comparison at a spacetime point between unknown generic states to be characterized as such states and the known family of probabilistic mixtures of equilibrium states. Taking advantage of the local nature of the problem, we extend the formalism to the general-relativistic context with curved spacetimes.Comment: Dedicated to Professor Hiroshi Ezawa on the occasion of his seventieth birthda