English

Hubble Parameter in Bulk Viscous Cosmology

General Relativity and Quantum Cosmology 2009-12-02 v1

Abstract

We discuss influences of bulk viscosity on the Early Universe, which is modeled by Friedmann-Robertson-Walker metric and Einstein field equations. We assume that the matter filling the isotropic and homogeneous background is relativistic viscous characterized by ultra-relativistic equations of state deduced from recent lattice QCD simulations. We obtain a set of complicated differential equations, for which we suggest approximate solutions for Hubble parameter HH. We find that finite viscosity in Eckart and Israel-Stewart fluids would significantly modify our picture about the Early Universe.

Keywords

Cite

@article{arxiv.0912.0115,
  title  = {Hubble Parameter in Bulk Viscous Cosmology},
  author = {A. Tawfik and H. Mansour and M. Wahba},
  journal= {arXiv preprint arXiv:0912.0115},
  year   = {2009}
}

Comments

4 pages, 2 eps figure, Talk given at 12th Marcel Grossmann Meeting on "General Relativity", Paris-France, 12-18 July 2009

R2 v1 2026-06-21T14:18:07.070Z