Thermodynamically allowed phantom cosmology with viscous fluid

TL;DR

This paper investigates the thermodynamic properties of a viscous cosmological model in the phantom regime, incorporating chemical potential and irreversible processes to ensure positive temperature and entropy.

Contribution

It introduces a thermodynamic analysis of phantom cosmology with viscous fluids, including chemical potential and irreversible processes, ensuring positive temperature and entropy.

Findings

Negative chemical potential possible in phantom regime

Positive temperature and entropy maintained

Thermodynamic consistency achieved in viscous phantom models

Abstract

In this work we present an analysis of the phantom zone in a causal viscous cosmology from a thermodynamic point of view. In this description we consider a chemical potential and the approach of irreversible processes. We assume a flat universe filled with a single dissipative fluid described by a barotropic equation of state, $p = \omega \rho$. This model allows to construct a negative chemical potential for the phantom regime but also this construction allows us to have positive definite temperature and entropy.