Cosmological Backreaction from Perturbations
Astrophysics
2008-11-26 v2 General Relativity and Quantum Cosmology
Abstract
We reformulate the averaged Einstein equations in a form suitable for use with Newtonian gauge linear perturbation theory and track the size of the modifications to standard Robertson-Walker evolution on the largest scales as a function of redshift for both Einstein de-Sitter and Lambda CDM cosmologies. In both cases the effective energy density arising from linear perturbations is of the order of 10^-5 the matter density, as would be expected, with an effective equation of state w ~ -1/19. Employing a modified Halofit code to extend our results to quasilinear scales, we find that, while larger, the deviations from Robertson-Walker behaviour remain of the order of 10^-5.
Cite
@article{arxiv.0710.4964,
title = {Cosmological Backreaction from Perturbations},
author = {Juliane Behrend and Iain A. Brown and Georg Robbers},
journal= {arXiv preprint arXiv:0710.4964},
year = {2008}
}
Comments
15 pages, 8 figures; replaced by version accepted by JCAP