Viscous coupled fluids in terms of a log-corrected equation of state

TL;DR

This paper introduces a viscous, log-corrected power-law equation of state for cosmological fluids, modeling late-time acceleration and dark matter interaction, providing new insights into cosmic evolution.

Contribution

It develops a coupled viscous log-corrected fluid model with dark matter, extending previous nonviscous, non-interacting models to better explain cosmic acceleration.

Findings

Derived expressions for energy densities of coupled fluids.

Compared viscous and nonviscous models, highlighting differences.

Showed the model's potential to explain late-time acceleration.

Abstract

We consider a class of cosmological fluids that possess properties analogous to those of crystalline solids undergoing isotropic deformations. Our research is based on a modified log-corrected power-law equation of state in the presence of a bulk viscosity. This formalism represents a class of so-called logotropic fluids, and allows explaining an accelerating late-time universe. In order to obtain a more detailed picture of its evolution, we add in our model a coupling of the log-corrected power-law fluid to dark matter, and study various interacting forms between them. We solve the system of equations for a modified log-power-law fluid coupled to dark matter, and obtain expressions for the log-corrected power-law energy density, and the energy density for dark matter. A comparative analysis is made with the model of a nonviscous log-corrected power-law fluid without interaction with dark matter.