A FRW Dark Fluid with a Non-Linear Inhomogeneous Equation of State

TL;DR

This paper explores a dark fluid model governed by a non-linear inhomogeneous equation of state, capable of describing phase transitions, cosmic acceleration, and potentially explaining early universe anisotropies.

Contribution

It introduces a novel dark fluid model with a non-linear inhomogeneous equation of state that unifies phase transition behavior and cosmic acceleration phenomena.

Findings

Model exhibits phase transitions from non-phantom to phantom regimes

Can describe quintessence-like cosmic acceleration

Suggests dark fluid origin of early universe anisotropies

Abstract

A dark Friedman-Robertson-Walker fluid governed by a non-linear inhomogeneous equation of state is considered which can be viewed as a conveniently simple paradigm for a whole class of models which exhibit phase transitions from a non-phantom towards a phantom era (superacceleration transition). From another side, such dark fluid models may describe also quintessence-like cosmic acceleration. Thermodynamical considerations for the processes involved, which are of great importance in the characterization of the global evolution of the corresponding universe, are given too. Connecting the proposed equation of state with an anisotropic Kasner universe with viscosity, we are led to the plausible conjecture of a dark fluid origin of the anisotropies in the early universe.