Cosmic bulk viscosity through backreaction
Abstract
We consider an effective viscous pressure as the result of a backreaction of inhomogeneities within Buchert's formalism. The use of an effective metric with a time-dependent curvature radius allows us to calculate the luminosity distance of the backreaction model. This quantity is different from its counterpart for a "conventional" spatially flat bulk viscous fluid universe. Both expressions are tested against the SNIa data of the Union2.1 sample with only marginally different results for the distance-redshift relation and in accordance with the CDM model. Future observations are expected to be able to discriminate among these models on the basis of indirect measurements of the curvature evolution.
Cite
@article{arxiv.1512.07835,
title = {Cosmic bulk viscosity through backreaction},
author = {Rodrigo M. Barbosa and G. Eddy and I. Chirinos and Winfried Zimdahl and Oliver F. Piattella},
journal= {arXiv preprint arXiv:1512.07835},
year = {2016}
}
Comments
18 pages, 6 figures, comments and references added, accepted for publication in GRG