Phantom behaviour and growth index anomalous evolution in viable f(R) gravity models
Cosmology and Nongalactic Astrophysics
2011-01-25 v2
Abstract
We present numerical calculation of the evolution of a background space-time metric and sub-horizon matter density perturbations in viable gravity models of present dark energy and cosmic acceleration. We found that viable models generically exhibit recent crossing of the phantom boundary . Moreover, as a consequence of the anomalous growth of density perturbations during the end of the matter-dominated stage, their growth index evolves non-monotonically with time and may even become negative.
Cite
@article{arxiv.1002.0462,
title = {Phantom behaviour and growth index anomalous evolution in viable f(R) gravity models},
author = {Hayato Motohashi and Alexei A. Starobinsky and Jun'ichi Yokoyama},
journal= {arXiv preprint arXiv:1002.0462},
year = {2011}
}
Comments
7 pages, 6 figures. To be published in the Proceedings of 19th Workshop in General Relativity and Gravitation in Japan (JGRG19); Figures 2 and 3 are replaced