Consistency of $f(R)=\sqrt{R^{2}-R_{0}^2}$ Gravity with the Cosmological Observations in Palatini Formalism

TL;DR

This paper investigates a specific modified gravity model using Palatini formalism, testing its consistency with various cosmological observations and constraining its parameters to match empirical data.

Contribution

It provides the first comprehensive observational constraints on the $f(R)=\sqrt{R^{2}-R_{0}^2}$ gravity model within the Palatini formalism.

Findings

Model parameters constrained to $R_0=6.192_{-0.177}^{+0.167} imes H_0^2$ and $\Omega_m=0.278_{-0.278}^{+0.273}$.

The model is consistent with supernova, CMB, BAO, and large-scale structure data.

Age of the universe matches the ages of old cosmological objects.

Abstract

In this work we study the dynamics of universe in $f(R)=\sqrt{R^2-R_{0}^2}$ modified gravity with Palatini formalism. We use data from recent observations as Supernova Type Ia (SNIa) Gold sample and Supernova Legacy Survey (SNLS) data, size of baryonic acoustic peak from Sloan Digital Sky Survey (SDSS), the position of the acoustic peak from the CMB observations and large scale structure formation (LSS) from the 2dFGRS survey to put constraint on the parameters of the model. To check the consistency of this action, we compare the age of old cosmological objects with the age of universe. In the combined analysis with the all the observations, we find the parameters of model as $R_0=6.192_{-0.177}^{+0.167}\times H_0^2$ and $\Omega_m=0.278_{-0.278}^{+0.273}$.