Revisiting Chaplygin gas cosmologies with the recent observations of high-redshfit quasars

TL;DR

This study uses recent high-redshift quasar data to constrain various Chaplygin gas models as unified dark matter and dark energy candidates, comparing their consistency with the standard cosmological model through multiple statistical diagnostics.

Contribution

It provides updated constraints on several Chaplygin gas models using the latest quasar observations and applies advanced statistical methods to distinguish these models from the standard cosmological model.

Findings

Standard ruler data yields tighter parameter constraints.

Matter density and Hubble constant align with Planck 2018 results.

MCG and VGCG models are favored by statistical support.

Abstract

In this paper, we use the latest observations of quasars covering the redshift range of $0.04<z<5.1$ to investigate a series of Chaplygin gas models as candidates for unified dark matter and dark energy. Based on different combinations of available standard candle and standard ruler data, we put constraints on the generalized Chaplygin gas (GCG), modified Chaplygin gas (MCG), new generalized Chaplygin gas (NGCG) and viscous generalized Chaplygin gas (VGCG) models. Moreover, we apply Jensen-Shannon divergence (JSD), statefinder diagnostics, and the deviance information criterion (DIC) to distinguish these CG models, based on the statistical results derived from Markov chain Monte Carlo method. The results show that (1) The standard ruler data could provide more stringent constraints on the cosmological parameters of different CG models considered in this analysis. Interestingly, the matter density parameter $\Omega_{m}$ and Hubble constant $H_{0}$ derived from the available data are well consistent with those from the Planck 2018 results; (2) Based on the statistical criteria JSD, our findings demonstrate the well consistency between Chaplygin gas and the concordance $\Lambda$CDM model. However, in the framework of statefinder diagnostics, the GCG and NGCG models cannot be distinguished from $\Lambda$CDM, while MCG and VGCG models show significant deviation from $\Lambda$CDM in the present epoch; (3) According to the the statistical criteria DIC, we show that the MCG and VGCG models have substantial observational support from high-redshfit quasars, whereas the GCG and NGCG models miss out on the less observational support category but can not be ruled out.