Observational Constraints on Exponential Gravity

TL;DR

This paper investigates observational constraints on an exponential f(R) gravity model using multiple cosmological data sets, deriving bounds on model parameters and the matter density.

Contribution

It provides the first comprehensive observational analysis of the exponential gravity model with current cosmological data.

Findings

Lower bound on beta parameter at 1.27 (95% CL)

Matter density parameter constrained between 0.245 and 0.311 (95% CL)

Best-fit model parameters identified

Abstract

We study the observational constraints on the exponential gravity model of f(R)=-beta*Rs(1-e^(-R/Rs)). We use the latest observational data including Supernova Cosmology Project (SCP) Union2 compilation, Two-Degree Field Galaxy Redshift Survey (2dFGRS), Sloan Digital Sky Survey Data Release 7 (SDSS DR7) and Seven-Year Wilkinson Microwave Anisotropy Probe (WMAP7) in our analysis. From these observations, we obtain a lower bound on the model parameter beta at 1.27 (95% CL) but no appreciable upper bound. The constraint on the present matter density parameter is 0.245< Omega_m^0<0.311 (95% CL). We also find out the best-fit value of model parameters on several cases.