Particle propagation in cosmological backgrounds
Abstract
We study the quantum propagation of particles in cosmological backgrounds, by considering a doublet of massive scalar fields propagating in an expanding universe, possibly filled with radiation. We focus on the dissipative effects related to the expansion rate. At first order, we recover the expected result that the decay rate is determined by the local temperature. Beyond linear order, the decay rate has an additional contribution governed by the expansion parameter. This latter contribution is present even for stable particles in the vacuum. Finally, we analyse the long time behaviour of the propagator and briefly discuss applications to the transPlanckian question.
 Publication:

Journal of Physics A Mathematical General
 Pub Date:
 June 2007
 DOI:
 10.1088/17518113/40/25/S37
 arXiv:
 arXiv:0704.0456
 Bibcode:
 2007JPhA...40.6901A
 Keywords:

 General Relativity and Quantum Cosmology
 EPrint:
 7 pages. To appear in the proceedings of the IRGAC 2006 conference