Growth factor parametrization and modified gravity

Abstract

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 $\gamma =0.64_{-0.15}^{+0.17}$. For the Dvali-Gabadadze-Porrati model, we find that $\gamma =0.55_{-0.13}^{+0.14}$.

7 figures, use revtex, v2: minor corrections, PRD in press

References in corpus (19)

• New Hubble Space Telescope Discoveries of Type Ia Supernovae at z > 1: Narrowing Constraints on the Early Behavior of Dark Energy
• Improved Cosmological Constraints from New, Old and Combined Supernova Datasets
• Observational Constraints on the Nature of the Dark Energy: First Cosmological Results from the ESSENCE Supernova Survey
• Two new diagnostics of dark energy
• A test of the nature of cosmic acceleration using galaxy redshift distortions
• WMAP constraints on low redshift evolution of dark energy
• Distinguishing Modified Gravity from Dark Energy
• Dark Energy versus Modified Gravity
• Testing LCDM with the Growth Function δ(a): Current Constraints
• On the growth of linear perturbations
• Differentiating dark energy and modified gravity with galaxy redshift surveys
• Observational constraints on the linear fluctuation growth rate
• The growth of matter perturbations in some scalar-tensor DE models
• Growth Index of DGP Model and Current Growth Rate Data
• Nonlinear growth in modified gravity theories of dark energy
• Parameterizing the Effect of Dark Energy Perturbations on the Growth of Structures
• Neutrino Mass, Dark Energy, and the Linear Growth Factor
• Constraints on alternative models to dark energy
• Dark energy and cosmic curvature: Monte-Carlo Markov Chain approach

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