Probing Dark Energy in The scope of Bianchi type I Spacetime

TL;DR

This study uses Hubble parameter measurements and supernova data to constrain Bianchi type I dark energy models, comparing them with flat CDM, and evaluates model performance with AIC and Bayes factor tests.

Contribution

It provides the first constraints on Bianchi type I dark energy models using combined Hubble and supernova data, and compares their fit to flat CDM.

Findings

Joint datasets yield lower parameter values.

Bianchi I model constraints are consistent with CDM.

Model comparison favors simpler models based on AIC and Bayes factor.

Abstract

It is well known that flat FRW metric is a special case of Bianchi type I spacetime. In this paper, we use 38 Hubble parameter, $H(z)$, measurements at intermediate redshifts $0.07\leq z\leq 2.36$ and its joint combination with the latest \textgravedbl joint light curves\textacutedbl (JLA) sample, comprised of 740 type Ia supernovae in the redshift range $z \epsilon [0.01, 1.30]$ to constrain the parameters of Bianchi type I dark energy model. We also use the same datasets to constrain flat $\Lambda$CDM Model. In both cases, we specifically address the expansion rate $H_{0}$ as well as the transition redshift $z_{t}$ determinations out of these measurements. In both Models we found that using joint combination of datasets gives rise to lower values for model parameters. Also to compare the considered cosmologies, we have made Akaike information criterion (AIC) and Bayes factor ($\Psi$) tests.