Energy conditions and entropy density of the universe

TL;DR

This paper explores the relationship between energy conditions and the entropy density of the universe within the FLRW model, comparing theoretical predictions with observational data to assess the validity of different energy conditions.

Contribution

It introduces an extended analysis linking energy conditions to entropy density and compares theoretical and observational entropy densities using multiple cosmological probes.

Findings

Dominant energy condition fits observational data better.

Entropy density depends on the Hubble parameter H(z).

Theoretical and observational entropy densities show consistency.

Abstract

In the standard Friedmann-Lemaitre-Robertson-Walker (FLRW) cosmological model, the energy conditions provides model-independent bounds on the behavior of the distance modulus. However, this method can not provide us the detailed information about the violation between the energy conditions and the observation. In this paper, we present an extended analysis of the energy conditions based upon the entropy density of the universe. On the one hand, we find that these conditions imply that entropy density s depends on Hubble parameter H(z). On the other hand, we compare the theoretical entropy density from the conservation law of energy-momentum tensor with that from the energy conditions using the observational Hubble parameter. When we consider a FLRW universe, according to the theoretical prediction, OHD, thermodynamics and several independent cosmological probes, show that the dominant energy condition is fitter than other energy conditions.