Exact solutions of a Flat Full Causal Bulk viscous FRW cosmological model through factorization

TL;DR

This paper derives exact solutions for a flat causal bulk viscous FRW cosmological model using the factorization method, revealing relationships between parameters and finding solutions for specific cases like s=1/2.

Contribution

It introduces the factorization method to find new exact solutions and explores the special case s=1/2 with scaling symmetries in the model.

Findings

Existence of a relationship between viscosity parameter s and equation of state parameter γ.

Derivation of new exact parametric solutions for different s values.

Identification of scaling symmetries for s=1/2 case.

Abstract

We study the classical flat full causal bulk viscous FRW cosmological model through the factorization method. The method shows that there exists a relationship between the viscosity parameter $s$ and the parameter $\gamma$ entering the equations of state of the model. Also, the factorization method allows to find some new exact parametric solutions for different values of the viscous parameter $s$. Special attention is given to the well known case $s=1/2$, for which the cosmological model admits scaling symmetries. Furthermore, some exact parametric solutions for $s=1/2$ are obtained through the Lie group method.