Quantum Statistical Processes in the Early Universe

TL;DR

This paper applies quantum open system and non-equilibrium statistical mechanics concepts to early universe cosmology, exploring noise, fluctuation, and decoherence in quantum fields and spacetime, and proposing a statistical definition of gravitational entropy.

Contribution

It introduces the concept of geometrodynamic noise and discusses the universe as an open system, bridging quantum statistical methods with cosmological phenomena.

Findings

Identification of noise sources in quantum fields and spacetime

Proposal of a statistical mechanical definition of gravitational entropy

Discussion of the universe as an open quantum system

Abstract

We show how the concept of quantum open system and the methods in non-equilibrium statistical mechanics can be usefully applied to studies of quantum statistical processes in the early universe. We first sketch how noise, fluctuation, dissipation and decoherence processes arise in a wide range of cosmological problems. We then focus on the origin and nature of noise in quantum fields and spacetime dynamics. We introduce the concept of geometrodynamic noise and suggest a statistical mechanical definition of gravitational entropy. We end with a brief discussion of the theoretical appropriateness to view the physical universe as an open system.