On the Viability of a Non-Analytical f(R)-Theory

TL;DR

This paper investigates a modified gravity theory with a power-law correction to Einstein-Hilbert action, demonstrating its viability through Solar-System tests and cosmological modeling, with specific constraints on its parameters.

Contribution

It introduces a non-analytical f(R) gravity model that passes Solar-System tests and accurately reproduces the Universe's thermal history, providing new constraints on model parameters.

Findings

Model passes Solar-System tests for exponent between 2 and 3

Two constraints on the length scale: lower from Solar-System, upper from cosmology

Successfully reproduces main phases of the Universe's thermal history

Abstract

In this paper, we show how a power-law correction to the Einstein-Hilbert action provides a viable modified theory of gravity, passing the Solar-System tests, when the exponent is between the values 2 and 3. Then, we implement this paradigm on a cosmological setting outlining how the main phases of the Universe thermal history are properly reproduced. As a result, we find two distinct constraints on the characteristic length scale of the model, i.e., a lower bound from the Solar-System test and an upper one by guaranteeing the matter dominated Universe evolution.