Cosmological constrains on new generalized Chaplygin gas model

TL;DR

This study investigates the new generalized Chaplygin gas model using cosmological data, constraining its parameters and comparing its fit to observations against the standard CDM model, with implications for dark energy and the Hubble constant tension.

Contribution

The paper provides the first comprehensive parameter constraints on the NGCG model using multiple data sets and compares its performance to the standard CDM cosmology.

Findings

NGCG model's matter density aligns with CDM.

DE equation of state slightly favors phantom regime.

NGCG alleviates Hubble tension but fits data less well than CDM.

Abstract

We use different combinations of data samples to investigate the new generalized Chaplygin gas (NGCG) model in the context of dark energy (DE) cosmology. Using the available cosmological data, we put constraints on the the free parameters of NGCG model based on the statistical Markov chain Monte Carlo method. We then find the best fit values of cosmological parameters and those confidence regions in NGCG cosmology. Our result for the matter density parameter calculated in NGCG model is in excellent agreement with that of the standard CDM cosmology. We also find that the equation of state of DE of the model slightly favors the phantom regime. We show that the big tension between the low- and high-redshift observations appearing in CDM universe to predict the Hubble constant H 0 can be alleviated in NGCG model. However, from the statistical point of view, our results show that the standard CDM model fits the observations better than the NGCG cosmology.