Phantom behaviour and growth index anomalous evolution in viable f(R) gravity models
Abstract
We present numerical calculation of the evolution of a background space-time metric and sub-horizon matter density perturbations in viable $f(R)$ gravity models of present dark energy and cosmic acceleration. We found that viable models generically exhibit recent crossing of the phantom boundary $w_{DE}=-1$. 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.
- Publication:
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arXiv e-prints
- Pub Date:
- February 2010
- DOI:
- 10.48550/arXiv.1002.0462
- arXiv:
- arXiv:1002.0462
- Bibcode:
- 2010arXiv1002.0462M
- Keywords:
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- Astrophysics - Cosmology and Extragalactic Astrophysics
- E-Print:
- 7 pages, 6 figures. To be published in the Proceedings of 19th Workshop in General Relativity and Gravitation in Japan (JGRG19)