Viscous {\Lambda}CDM Universe Models

TL;DR

This paper investigates flat { extLambda}CDM cosmological models incorporating bulk viscosity, deriving and solving their dynamical equations, and analyzing their evolution and statefinder parameters to understand the impact of viscosity.

Contribution

It introduces analytical and numerical solutions for viscous { extLambda}CDM models and evaluates their evolution using statefinder diagnostics.

Findings

Analytical solutions for specific bulk viscosity cases.

Numerical solutions for the general case.

Statefinder analysis in the s-r-plane.

Abstract

We explore flat {\Lambda}CDM models with bulk viscosity, and study the role of the bulk viscosity in the evolution of these universe models. The dynamical equations for these models are obtained and solved for some cases of bulk viscosity. We obtain differential equations for the Hubble parameter H and the energy density of dark matter {\rho}, for which we give analytical solutions for some cases and for the general case we give a numerical solution. Also we calculate the statefinder parameters for this model and display them in the s-r-plane.