Observational constraints on Luciano-Saridakis entropic cosmology

TL;DR

This paper tests a new entropic cosmology model based on Luciano and Saridakis's generalized entropy, showing it fits observational data well and may help resolve the Hubble tension.

Contribution

First observational constraints on Luciano-Saridakis entropic cosmology demonstrating its viability and potential to address the Hubble tension.

Findings

Model fits combined observational data robustly.

Can satisfy Pantheon+, SH0ES, and CMB constraints simultaneously.

Excludes the standard $ ext{Lambda}$CDM limit at 2$\sigma$.

Abstract

A recently proposed generalized entropy by Luciano and Saridakis extends the standard Boltzmann-Gibbs and Bekenstein-Hawking framework through a microscopically motivated construction involving two independent entropic exponents. When applied within the gravity-thermodynamics correspondence, this entropy leads to a modified cosmological dynamics that can be interpreted as an effective dark energy sector of entropic origin, while recovering $\Lambda$CDM in appropriate limits. In this work, we perform the first observational confrontation of the resulting entropic cosmology at the background level. Focusing on the case $\alpha_\delta=0$, we constrain the model using Cosmic Chronometers, Pantheon$^+$ Type Ia supernovae calibrated with SH0ES, BAO measurements from DESI DR2 and compressed Planck 2018 CMB information. We find that the model yields a statistically robust fit to the combined data sets and can simultaneously satisfy Pantheon$^+$, SH0ES and CMB shift-parameter constraints, unlike $\Lambda$CDM. Although the entropic parameters remain close to their standard values, the $\Lambda$CDM limit is excluded at the $2\sigma$ level within the restricted parameter space considered. These results indicate that the Luciano-Saridakis entropic cosmology offers a viable extension of the standard model with the potential to alleviate the Hubble tension at the background level.