Thermodynamic parametrization of dark energy

TL;DR

This paper introduces a thermodynamics-inspired, model-independent parametrization of dark energy using Padé polynomials, compatible with cosmic history and structure formation, and tests it against recent observational data.

Contribution

It presents a novel, divergence-free parametrization of dark energy based on thermodynamics, encompassing the mbda CDM model as a special case, and performs comprehensive data analysis.

Findings

The model fits current cosmic data well.

Dark energy evolution features are consistent with standard cosmology.

The approach provides a flexible framework for future dark energy studies.

Abstract

We propose a model-independent parametrization of dark energy motivated by thermodynamics. To this aim, we consider Pad\'e polynomials to reconstruct the form of deceleration parameter adequate to describe different epochs of cosmic history and divergence-free in the far future. The proposed scenario also fulfills the demand of structure formation and contains the $\Lambda$CDM model as a limiting case. Thus, a numerical analysis at both background and perturbation levels is performed through the Markov Chain Monte Carlo method in view of the most recent cosmic data. We then use the observational constraints to explore the features of dark energy evolution and compare our findings with the predictions of the standard cosmological model.