Addressing $H_0$ and $S_8$ tensions within $f(Q)$ cosmology

Abstract

We investigate the viability of $f(Q)$ gravity as an alternative framework to address the $H_0$ and $S_8$ tensions in cosmology. Focusing on three representative $f(Q)$ models, we perform a comprehensive Bayesian analysis using a combination of cosmological observations, including cosmic chronometers, Type Ia supernovae, gamma-ray bursts, baryon acoustic oscillations, and CMB distance priors. Our results demonstrate that most of these models can yield higher values of $H_0$ than those predicted by $Λ$CDM, offering a partial alleviation of the tension. In addition, one model satisfies the condition $G_{\mathrm{eff}} < G$, making it a promising candidate for addressing the $S_8$ tension. However, these improvements are accompanied by mild internal inconsistencies between different subsets of data, which limit the overall statistical preference relative to $Λ$CDM. Despite this, $f(Q)$ gravity remains a promising and flexible framework for late-time cosmology, and our results motivate further exploration of extended or hybrid models that may reconcile all observational constraints.

20 pages, 5 figures, 3 tables, REVTeX 4.2. Version accepted for publication in JCAP