Thawing Versus. Tracker Behaviour: Observational Evidence

TL;DR

This study compares thawing and tracker scalar field dark energy models using observational data, finding no clear evidence for either in background cosmology but supporting thawing behavior when considering inhomogeneities.

Contribution

It introduces a Bayesian analysis of scalar field models with GCG parametrization, highlighting the importance of inhomogeneity evolution in distinguishing dark energy behaviors.

Findings

No clear evidence for thawing or tracker behavior in background cosmology.

Significant evidence supporting thawing behavior when inhomogeneities are considered.

Inhomogeneity evolution provides crucial insights into dark energy models.

Abstract

Currently there is a variety of scalar field models to explain the late time acceleration of the Universe. This includes the standard canonical and non-canonical scalar field models together with recently proposed Galileon scalar field models. One can divide all these scalar field models into two broad categories, namely the thawing and the tracker class. In this work we investigate the evidence for these models with the presently available observational data using the Bayesian approach. We use the Generalized Chaplygin Gas (GCG) parametrization for dark energy equation of state (EoS) as it gives rise to both the thawing and tracking behaviours for different values of the parameters. Analysis of the observational data does not give any clear evidence for either thawing or tracking behaviour within the context of background cosmology, However, if we consider the evolution of inhomogenities and analyze the data in this context then there is a significant evidence in favour of thawing behaviour.