Astronomy and Astrophysics – Astrophysics
Scientific paper
2008-08-09
Phys.Rev.D78:123010,2008
Astronomy and Astrophysics
Astrophysics
7 figures, use revtex, v2: minor corrections, PRD in press
Scientific paper
10.1103/PhysRevD.78.123010
The growth rate of matter perturbation and the expansion rate of the Universe can be used to distinguish modified gravity and dark energy models in explaining the cosmic acceleration. The growth rate is parametrized by the growth index $\gamma$. We discuss the dependence of $\gamma$ on the matter energy density $\Omega$ and its current value $\Omega_0$ for a more accurate approximation of the growth factor. The observational data, including the data of the growth rate, are used to fit different models. The data strongly disfavor the Dvali-Gabadadze-Porrati model. For the dark energy model with a constant equation of state, we find that $\Omega_0=0.27\pm 0.02$ and $w=-0.97\pm 0.09$. For the $\Lambda$CDM model, we find that $\gamma=0.64^{+0.17}_{-0.15}$. For the Dvali-Gabadadze-Porrati model, we find that $\gamma=0.55^{+0.14}_{-0.13}$.
No associations
LandOfFree
Growth factor parametrization and modified gravity does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Growth factor parametrization and modified gravity, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Growth factor parametrization and modified gravity will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-11178