Dynamical stability in scalar-tensor cosmology

TL;DR

This paper investigates the stability and evolution of a double scalar-tensor cosmological model, showing it can mimic dark energy behaviors and transition between different cosmic acceleration phases.

Contribution

It introduces a phase space analysis of a double scalar-tensor theory, constrained by observational data, revealing its potential to describe dark energy dynamics.

Findings

Model behaves like quintom dark energy

Predicts transition from quintessence to phantom

Constrained parameters with observational data

Abstract

We study FRW cosmology for a double scalar - tensor theory of gravity where two scalar fields are nonminimally coupled to the geometry. In a framework to study stability and attractor solutions of the model in the phase space, we constraint the model parameters with the observational data. For an accelerating universe, the model behaves like quintom dark energy models and predicts a transition from quintessence era to phantom era.