Observational constraints on new class dark energy parameterized EoS in Bianchi type-I universe

Abstract

This study presents an extensive study of a class of time-evolving dark energy models defined by parametrized equations of state (EoS) parameter in the context of a spatially homogeneous yet anisotropic Bianchi type-I universe. In particular, we employ two distinct parametrization of the EoS parameter and thoroughly investigate their impact on the cosmic expansion history in the model. We utilize a diverse dataset composed of the cosmic chronometers, baryon acoustic oscillations (BAO), the cosmic microwave background (CMB), and the Pantheon+SH0ES supernova type Ia sample to impose constraints on the model parameters through the Bayesian analysis with the Markov Chain Monte Carlo (MCMC) approach. We also examine the crucial cosmological quantities such as the Hubble parameter, deceleration parameter, jerk parameter, and the effective EoS parameter to provide a comprehensive understanding of the cosmic evolution in the models. Moreover, we utilize the diagnostic parameters Om(z) and the statefinder (r, s) to examine the difference between the studied models and the ΛCDM model. To further strengthen the study, we assess the statistical performance of the models using the Akaike Information Criterion (AIC) and the Bayesian Information Criterion (BIC). The isotropic models and their anisotropic extensions exhibit the accelerating universe expansion, and we demonstrate different aspects of these models with reference to the ΛCDM model and CPL parametrization based dark energy model.