Stability properties of some perfect fluid cosmological models
Abstract
Flat FriedmannRobertsonWalker (FRW) perfect fluid cosmologies can be reproduced as particular solutions of suitable fieldtheoretical models. Here we investigate the stability of perfect fluid model trajectories with respect to sets of trajectories of the corresponding field models having generic initial conditions. It is shown that the trajectories of barotropic perfect fluid models and those of the Chaplygin gas model are stable. The total probability to reach the Chaplygin gas regime early enough to achieve a matter dominated stage having a realistic duration is calculated for a scalar field model assuming a natural measure in the space of initial conditions taken near a cosmological singularity. An example is presented of a twofluid cosmological model where the stability is partially absent.
 Publication:

Physical Review D
 Pub Date:
 November 2005
 DOI:
 10.1103/PhysRevD.72.103518
 arXiv:
 arXiv:astroph/0504576
 Bibcode:
 2005PhRvD..72j3518G
 Keywords:

 98.80.Cq;
 98.80.Jk;
 Particletheory and fieldtheory models of the early Universe;
 Mathematical and relativistic aspects of cosmology;
 Astrophysics;
 General Relativity and Quantum Cosmology;
 High Energy Physics  Theory
 EPrint:
 Discussion about the inclusion of radition into the model is enlarged and results of numerical calculations are presented. Final version, to appear in Phys. Rev. D