Collisional equilibrium, particle production and the inflationary universe
Abstract
Particle production processes in the expanding universe are described within a simple kinetic model. The equilibrium conditions for a Maxwell-Boltzmann gas with variable particle number are investigated. We find that radiation and nonrelativistic matter may be in equilibrium at the same temperature provided the matter particles are created at a rate that is half the expansion rate. Using the fact that the creation of particles is dynamically equivalent to a nonvanishing bulk pressure we calculate the backreaction of this process on the cosmological dynamics. It turns out that the `adiabatic' creation of massive particles with an equilibrium distribution for the latter necessarily implies power-law inflation. Exponential inflation in this context is shown to become inconsistent with the second law of thermodynamics after a time interval of the order of the Hubble time.
Keywords
Cite
@article{arxiv.gr-qc/9608038,
title = {Collisional equilibrium, particle production and the inflationary universe},
author = {Winfried Zimdahl and Josep Triginer and Diego Pavon},
journal= {arXiv preprint arXiv:gr-qc/9608038},
year = {2009}
}
Comments
19 pages, latex, no figures, to appear in Phys.Rev.D