Thermodynamic analysis for Non-linear system (Van-der-Waals EOS) with viscous cosmology

TL;DR

This paper analyzes the thermodynamics of Van-der-Waals fluid cosmology with viscosity, exploring stability, cosmic phases, and singularity resolution in different models, contributing to understanding accelerating universe phenomena.

Contribution

It introduces a detailed thermodynamic analysis of viscous Van-der-Waals fluid models in cosmology, including stability and singularity considerations, which is a novel approach.

Findings

Viscous effects influence cosmic acceleration.

Different Van-der-Waals models exhibit varied thermodynamic stability.

Finite time singularities can be addressed with viscosity.

Abstract

The following paper has been motivated from recent works of Kremer, G.M [1, 4], Vardiashvili, G [2], Jantsch, R.C [3], Capozziello, S [5] on Van-Der-Waals EOS cosmology. The main aim for this paper is to analyze the thermodynamics of a Non-linear system which in this case is Van-Der-Waals fluid EOS [6]. We have investigated the Van-Der-Waals fluid system with the generalized EOS as [8]. The third term signifies viscosity which has been considered as an external parameter that only modifies pressure but not the density of the liquid. The and are the two functions of energy density and time that are different for the 3 types of Vander Waal models namely one parameter model, two parameters model and three parameters model [7, 9]. The value of EOS parameter [6, 10] will show different values for different models. We have studied the changes in the parameters for different cosmic phases [4, 5, 6]. We have also studied the thermodynamics and the stability conditions for the three models while considering viscosity [10, 12, 13, 14]. We have discussed the importance of viscosity [11] for explaining accelerating universe with negative pressure [12]. Finally, we have resolved the finite time future singularity problems [15-20] and discussed the thermodynamics energy conditions [21-31] with those models.