Latest supernovae constraints on f(R) cosmologies

TL;DR

This paper uses recent supernova data, combined with other cosmological measurements, to constrain $f(R)$ gravity models, showing they can explain cosmic acceleration without dark energy.

Contribution

It provides new bounds on $f(R)=R - eta/R^n$ models using the latest supernova data and a joint analysis with BAO and CMB measurements.

Findings

$f(R)$ models can reproduce cosmic acceleration phases.

Constraints on model parameters $eta$, $n$, and $\

Abstract

A class of modified gravity, known as $f(R)$-gravity, has presently been applied to Cosmology as a realistic alternative to dark energy. In this paper we use the most recent Type-Ia Supernova (SNe Ia) data, the so-called \emph{Union} sample of 307 SNe Ia, to place bounds on a theory of the form $f(R)=R - \beta/R^n$ within the Palatini approach. Given the complementarity of SNe Ia data with other cosmological observables, a joint analysis with measurements of baryon acoustic oscillation peak and estimates of the {\rm CMB} shift parameter is also performed. We show that, for the allowed intervals of $n$, $\Omega_{mo}$, and $\beta$, models based on $f(R) = R - \beta/R^{n}$ gravity in the Palatini approach can produce the sequence of radiation-dominated, matter-dominated, and accelerating periods without need of dark energy.