Exploring the Dark Universe: constraints on dynamical Dark Energy models from CMB, BAO and growth rate measurements

TL;DR

This paper uses recent CMB, BAO, and growth rate data to constrain dynamical dark energy models, finding that interactive dark energy models are most favored by current observations, with some models fitting individual data sets better.

Contribution

It provides updated constraints on dynamical dark energy models using the latest observational data, highlighting the preference for interactive dark energy models over others.

Findings

Interactive dark energy model is most favored by data.

Slowdown of cosmic acceleration observed at low redshifts.

Some models fit individual data sets better than the standard ΛCDM.

Abstract

In order to explain the current acceleration of the Universe, the fine tuning problem of the cosmological constant $\Lambda$ and the cosmic coincidence problem, different alternative models have been proposed in the literature. We use the most recent observational data from CMB (Planck 2018 final data release) and LSS (SDSS, WiggleZ, VIPERS) to constrain dynamical dark energy (DE) models. The CMB shift parameter, which traditionally has been used to determine the main cosmological parameters of the standard model $\Lambda CDM$ is employed in addition to data from redshift-space distortions through the growth parameter $A(z)=f(z)\sigma_{8}(z)$ to constrain the mass variance $\sigma_{8}$. BAO data is also used to study the history of the cosmological expansion and the main properties of DE. From the evolution of $q(z)$ we found a slowdown of acceleration behaviour at low redshifts, and by using the Akaike and Bayesian Information Criterion (AIC, BIC) we discriminate different models those that are better suited to the observational data, finding that the interactive dark energy (IDE) model is the most favoured by observational data, including information from SNIa and Hz. The analysis shows that the IDE model is followed closely by EDE and $\Lambda CDM$ models, which in some cases fit better the observational data with individual probes.