Microcanonical quantum gravity

Abstract

Quantum gravity is equivalent to a statistical mechanical system of classical fields in 4 + 1 dimensions at temperatureħ. It is generically true that systems involving gravitation do not exist at fixed temperature. We therefore propose a fixed action description of quantum gravity. The formalism for a fixed action description of quantum field theory is developed. It is found to be equivalent to the canonical fixedħ formalism for renormalizable field theories. It is also found that, in precise analogy to the microcanonical formulation of statistical mechanics, it describes a wider class of theories than the canonical formalism.