Viable Singularity-Free f(R) Gravity Without a Cosmological Constant

TL;DR

This paper introduces a two-parameter f(R) gravity model that is cosmologically viable, free of singularities, compatible with relativistic stars, and distinguishable from Lambda-CDM, challenging previous claims about the limitations of such models.

Contribution

The authors propose a new two-parameter f(R) gravity model that overcomes previous issues, including singularities and compatibility with astrophysical objects.

Findings

Model is cosmologically viable and distinguishable from Lambda-CDM

Model is compatible with relativistic stars

Model is free of Ricci scalar singularities during evolution

Abstract

Several authors have argued that self-consistent $f(R)$ gravity models distinct from $\Lambda $CDM are almost ruled out. Confronting such claims, we present a particular two-parameter $f(R)$ model that: (a) is cosmologically viable and distinguishable from $\Lambda $CDM; (b) is compatible with the existence of relativistic stars; (c) is free of singularities of the Ricci scalar during the cosmological evolution and (d) allows the addition of high curvature corrections that could be relevant for inflation.