A hybrid model of viscous and Chaplygin gas to tackle the Universe acceleration

TL;DR

This paper introduces a hybrid viscous generalized Chaplygin gas model to explain the Universe's acceleration, constraining its parameters with multiple cosmological datasets and analyzing its potential to address the Hubble tension.

Contribution

It proposes a novel hybrid model combining viscosity and Chaplygin gas, and constrains its parameters using comprehensive observational data.

Findings

The VGCG model differs significantly from the standard cosmological model.

The model can potentially alleviate the Hubble constant tension.

Constraints on model parameters are obtained through Bayesian analysis.

Abstract

Motivated by two seminal models proposed to explain the Universe acceleration, this paper is devoted to study a hybrid model which is constructed through a generalized Chaplygin gas with the addition of a bulk viscosity. We call the model a Viscous Generalized Chaplygin Gas (VGCG) and its free parameters are constrained through several cosmological data like the Observational Hubble Parameter, Type Ia Supernovae, Baryon Acoustic Oscillations, Strong Lensing Systems, HII Galaxies and using Joint Bayesian analysis. In addition, we implement a Om-diagnostic to analyze the VGCC dynamics and its difference with the standard cosmological model. The hybrid model shows important differences when compared with the standard cosmological model. Finally, based on our Joint analysis we find that the VGCG could be an interesting candidate to alleviate the well-known Hubble constant tension.