English

Exact analytical solution for an Israel-Stewart Cosmology

General Relativity and Quantum Cosmology 2019-08-15 v3

Abstract

In this article we report a novel analytic solution for a cosmological model with a matter content described by a one component dissipative fluid, in the framework of the causal Israel-Stewart theory. Some physically well motivated analytical relations for the bulk viscous coefficient, the relaxation time and a bariotropic equation of state are postulated. We study within the parameter space, which label the solution, a suited region compatible with an accelerated expansion of the universe for late times, as well as stability properties of the solution at the critical parameter values γ=1 \gamma = 1 and for s=1/2 s = 1/2 . We study as well the consequences that arise from the positiveness of the entropy production along the time evolution. In general, the accelerated expansion at late times is only possible when ϵ1/18\epsilon\geq 1/18, which implies a very large non-adiabatic contribution the speed of sound.

Keywords

Cite

@article{arxiv.1812.05009,
  title  = {Exact analytical solution for an Israel-Stewart Cosmology},
  author = {Norman Cruz and Esteban González and Guillermo Palma},
  journal= {arXiv preprint arXiv:1812.05009},
  year   = {2019}
}

Comments

12 pages, 3 figures. We have partially rewritten the article emphasizing the mathematical aspects related to the new analytical solution found in the frame of a causal Israel-Stewart cosmology. The title as well as the abstract were slightly modified according to the former resubmission of the paper

R2 v1 2026-06-23T06:40:21.735Z