Cosmological data analysis of f(R) gravity models

TL;DR

This paper evaluates various f(R) gravity models against multiple cosmological and solar system data, finding that most are ruled out except for the exponential inverse curvature model, which remains consistent with current observations.

Contribution

It provides a comprehensive confrontation of f(R) gravity models with cosmological and solar system data, identifying the exponential inverse curvature model as viable.

Findings

Most f(R) models are ruled out by combined data.

The exponential inverse curvature model satisfies observational constraints.

Future data could distinguish small deviations from standard gravity.

Abstract

A class of well-behaved modified gravity models with long enough matter domination epoch and a late-time accelerated expansion is confronted with SNIa, CMB, SDSS, BAO and H(z) galaxy ages data, as well as current measurements of the linear growth of structure. We show that the combination of geometrical probes and growth data exploited here allows to rule out f(R) gravity models, in particular, the logarithmic of curvature model. We also apply solar system tests to the models in agreement with the cosmological data. We find that the exponential of the inverse of the curvature model satisfies all the observational tests considered and we derive the allowed range of parameters. Current data still allows for small deviations of Einstein gravity. Future, high precision growth data, in combination with expansion history data, will be able to distinguish tiny modifications of standard gravity from the LambdaCDM model.