Exponential $f(R)$ cosmology with massive neutrinos as a dynamical dark energy framework

TL;DR

This paper investigates an exponential $f(R)$ gravity model combined with massive neutrinos, showing it fits current cosmological data well, slightly alleviates the Hubble tension, and tightens neutrino mass constraints compared to standard models.

Contribution

It introduces and constrains an exponential $f(R)$ gravity model with massive neutrinos using latest cosmological data, highlighting its potential to address cosmological tensions.

Findings

Model remains consistent with observations

Slightly alleviates Hubble tension

Tighter neutrino mass constraints

Abstract

The exponential $f(R)$ gravity model provides a theoretically well-motivated extension of General Relativity, introducing a modified gravitational dynamics at late times consistent with a dynamical dark energy scenario, while recovering the $\Lambda$CDM-like regime at high redshifts with a smooth transition. Using a Bayesian Markov Chain Monte Carlo (MCMC) analysis, we constrain the parameters of the exponential $f(R)$ model in combination with the total neutrino mass $\sum m_\nu$, employing the latest measurements from cosmic chronometers, the DESI DR2 BAO data, the CMB acoustic scale, and the Pantheon+ supernovae compilation, comparing the results with the $\Lambda$CDM and the $w_0w_a$CDM models. Our results show that the exponential $f(R)$ model remains consistent with current observations while slightly alleviating the Hubble tension and the neutrino mass problem relative to $\Lambda$CDM, although the constraints on $\sum m_\nu$ are tighter than those obtained for the phenomenological $w_0w_a$CDM scenario. These results indicate that the interplay between modified gravity and neutrino physics in the late Universe may offer a viable framework for further investigation of cosmological tensions.