Vacuum viscosity and entropy generation in quantum gravitational processes in the early universe
Abstract
Entropy generation in quantum gravitational processes due to vacuum polarization and particle production in the early universe is discussed. The quantum processes of spontaneous and induced particle production from the vacuum and nparticle state as well as the classical process of nonadiabatic frequency shifts of normal modes of the system are described in the context of an adiabatic formulation of finite temperature quantum field theory and the thermodynamics of relativistic imperfect fluids. Vacuum viscosity arising from the interaction of the field vacua with dynamical spacetimes and kinematic viscosity arising from the nonadiabatic expansion of relativistic gases are defined and calculated for a number of representative systems of fields and background spacetimes. Their use in the description of dissipative processes in the early universe and their role in the definition of gravitational entropy are explored.
 Publication:

Cosmology of the Early Universe
 Pub Date:
 1984
 Bibcode:
 1984ceu..book...23H
 Keywords:

 Big Bang Cosmology;
 Entropy;
 Gravitation Theory;
 Particle Production;
 Quantum Theory;
 Unified Field Theory;
 Kinematic Equations;
 Relativistic Plasmas;
 SpaceTime Functions;
 Statistical Mechanics;
 Thermodynamics;
 Universe;
 Vacuum Effects;
 Viscosity;
 Astrophysics