Reexamining generalized Chaplygin gas with the sign-changeable interaction

TL;DR

This paper reexamines the generalized Chaplygin gas cosmology with a sign-changing interaction, revealing stable late-time de-Sitter attractors and oscillating interactions that address the coincidence problem.

Contribution

It introduces a detailed dynamical analysis of the GCG model with sign-changeable interaction, highlighting its late-time stability and oscillatory behavior.

Findings

Existence of de-Sitter attractors in the model

Interaction oscillates and tends to zero over time

Interaction switches from positive to negative depending on redshift

Abstract

In this paper, we reexamine the generalized Chaplygin gas (GCG) cosmology with the sign-changeable interaction. The dynamical analysis show that there exists de-Sitter attractors in this model, which means that the late-time behaviors of the model is insensitive to the initial condition and thus alleviates the coincidence problem. Furthermore, we find that this interaction oscillates and tends to zero finally by numerical calculations of the nonlinear equations. In some specific cases of initial conditions, the interaction is positive (the energy transition from dark energy to dark matter) at high redshift while it is negative (the energy transition from dark matter to dark energy) at low redshift for suitable ranges of the parameters.