Exploring the Hubble tension with a late time Modified Gravity scenario

TL;DR

This paper explores a late-time modified gravity model inspired by Loop Quantum Cosmology to address the Hubble tension, showing potential in reducing discrepancies but with limited overall fit improvement.

Contribution

Introduces a novel late-time modified gravity model with a parameter c, motivated by effective Loop Quantum Cosmology, to alleviate the Hubble tension.

Findings

Model reduces Hubble tension below 1σ with SH0ES data.

Overall fit to data is similar to ΛCDM, with Bayesian evidence favoring ΛCDM.

Theoretical basis supports subtle low-redshift modifications.

Abstract

We investigate a modified cosmological model aimed at addressing the Hubble tension, considering revised dynamics in the late Universe. The model introduces a parameter $c$ affecting the evolution equations, motivated by a modified Poisson algebra inspired by effective Loop Quantum Cosmology. Our analysis includes diverse background datasets such as Cosmic Chronometers, Pantheon+ Type Ia Supernovae (with and without the SH0ES calibration), SDSS, DESY6 and DESI Baryon Acoustic Oscillations, and background information of the Cosmic Microwave Background. We find that the model alleviates the Hubble tension in most of the dataset combinations, with cases reducing discrepancies to below $1\sigma$ when including SH0ES. However, the model exhibits minimal improvement in the overall fit when compared to $\Lambda$CDM, and Bayesian evidence generally favors the standard model. Theoretical foundations support this approach as a subtle adjustment to low-redshift dynamics, suggesting potential for further exploration into extensions of $\Lambda$CDM. Despite challenges in data fitting, our findings underscore the promise of small-scale modifications in reconciling cosmological tensions.