Stability of accelerating cosmology in two scalar-tensor theory: Little Rip versus de Sitter

TL;DR

This paper develops a reconstruction scheme for two scalar-tensor theories to describe non-singular Little Rip and de Sitter cosmologies, analyzing their stability and the implications for cosmic evolution.

Contribution

It introduces a general reconstruction method for two scalar models capable of describing Little Rip and de Sitter universes, and studies their stability and transition properties.

Findings

Little Rip universe stability indicates no classical transition to de Sitter space.

The model can describe non-singular cosmologies with different late-time behaviors.

Stability analysis reveals conditions under which these cosmologies persist or dissolve.

Abstract

We develop the general reconstruction scheme in two scalar model. The quintom-like theory which may describe (different) non-singular Little Rip or de Sitter cosmology is reconstructed. (In)stability of such dark energy cosmologies as well as the flow to fixed points is studied. The stability of Little Rip universe which leads to dissolution of bound objects sometime in future indicates that no classical transition to de Sitter space occurs.