Barrow Entropy Cosmology: an observational approach with a hint of stability analysis

TL;DR

This paper investigates a modified entropy-based cosmological model using observational data and dynamical systems analysis, finding results consistent with standard cosmology within 2σ confidence levels.

Contribution

It introduces a novel application of Barrow entropy to cosmology and combines observational constraints with stability analysis to explore its viability.

Findings

Constraints consistent with standard cosmology within 2σ

De Sitter solution identified at late times

Model explains late cosmic acceleration with new entropy terms

Abstract

In this work, we use an observational approach and dynamical system analysis to study the cosmological model recently proposed by Saridakis (2020), which is based on the modification of the entropy-area black hole relation proposed by Barrow (2020). The Friedmann equations governing the dynamics of the Universe under this entropy modification can be calculated through the gravity-thermodynamics conjecture. We investigate two models, one considering only a matter component and the other including matter and radiation, which have new terms compared to the standard model sourcing the late cosmic acceleration. A Bayesian analysis is performed in which we use five cosmological observations (observational Hubble data, type Ia supernovae, HII galaxies, strong lensing systems, and baryon acoustic oscillations) to constrain the free parameters of both models. From a joint analysis, we obtain constraints that are consistent with the standard cosmological paradigm within $2\sigma$ confidence level. In addition, a complementary dynamical system analysis using local and global variables is developed which allows obtaining a qualitative description of the cosmology. As expected, we found that the dynamical equations have a de Sitter solution at late times.