New observational constraints on $f(R)$ gravity from cosmic chronometers

TL;DR

This study uses multiple cosmological data sets to constrain four $f(R)$ gravity models, finding a slight preference for a small deviation from the standard $\\Lambda$CDM model, and demonstrating consistency with observations.

Contribution

It provides new observational constraints on four popular $f(R)$ gravity models using combined cosmological data, introducing a deviation parameter $b$ to quantify departures from $\\Lambda$CDM.

Findings

A small non-zero deviation from $\\Lambda$CDM is slightly favored.

$f(R)$ models are consistent with current cosmological observations.

The deviation parameter $b$ effectively quantifies differences from standard cosmology.

Abstract

We use the recently released cosmic chronometer data and the latest measured value of the local Hubble parameter, combined with the latest joint light curves of Supernovae Type Ia, and Baryon Acoustic Oscillation distance measurements, in order to impose constraints on the viable and most used $f(R)$ gravity models. We consider four $f(R)$ models, namely the Hu-Sawicki, the Starobinsky, the Tsujikawa, and the exponential one, and we parametrize them introducing a distortion parameter $b$ that quantifies the deviation from $\Lambda$CDM cosmology. Our analysis reveals that a small but non-zero deviation from $\Lambda$CDM cosmology is slightly favored, with the corresponding fittings exhibiting very efficient $AIC$ and $BIC$ Information Criteria values. Clearly, $f(R)$ gravity is consistent with observations, and it can serve as a candidate for modified gravity.