Nonlinear bulk viscosity and the stability of accelerated expansion in FRW spacetime

TL;DR

This paper investigates how nonlinear bulk viscosity in a viscous fluid can influence the stability of accelerated expansion in a Friedmann-Robertson-Walker universe, providing a potential explanation for dark energy effects.

Contribution

It introduces a nonlinear viscosity model into FRW cosmology and analyzes the stability of solutions, offering new insights into dark energy modeling.

Findings

Existence of stable accelerated expansion solutions.

Nonlinear viscosity can sustain cosmic acceleration.

Potential explanation for dark energy phenomena.

Abstract

In the context of dark energy solutions, we consider a Friedmann-Robertson-Walker spacetime filled with a non-interacting mixture of dust and a viscous fluid, whose bulk viscosity is governed by the nonlinear model proposed in [15]. Through a phase space analysis of the equivalent dynamical system, existence and stability of critical solutions are established and the respective scale factors are computed. The results point towards the possibility of describing the current accelerated expansion of the Universe by means of the abovementioned nonlinear model for viscosity.