Evolution of density perturbations in double exponential quintessence models

TL;DR

This paper studies how matter density perturbations evolve in double exponential quintessence models within Einstein and Brans-Dicke gravity frameworks, constrained by galaxy survey data.

Contribution

It introduces and analyzes double exponential quintessence models in both Einstein and Brans-Dicke theories, constrained by observational growth rate data.

Findings

Models are consistent with galaxy survey data.

Evolution of perturbations depends on the potential parameters.

Constraints limit the parameter space of the models.

Abstract

In this work we investigate the evolution of matter density perturbations for quintessence models with a self-interaction potential that is a combination of exponentials. One of the models is based on the Einstein theory of gravity, while the other is based on the Brans-Dicke scalar tensor theory. We constrain the parameter space of the models using the determinations for the growth rate of perturbations derived from data of the 2-degree Field Galaxy Redshift Survey.