Extended $\Lambda$CDM model and viscous dark energy: A Bayesian analysis

TL;DR

This paper introduces an extended $\\Lambda$CDM cosmological model incorporating viscous dark energy effects via a Bayesian analysis, utilizing multiple observational datasets to evaluate its viability and impact on universe expansion.

Contribution

It proposes a novel extended cosmological model with viscous dark energy based on nonextensive effects and Bayesian analysis of observational data to test its validity.

Findings

The extended model slightly modifies the universe's expansion dynamics.

Bayesian analysis constrains viscosity parameters consistent with observational data.

The model's fit compares favorably with standard $\Lambda$CDM in certain datasets.

Abstract

We propose an approach considering the nonextensive effects in the context of the Verlinde theory in order to address an extended cosmological model in the context of viscous dark energy. Specifically, this model leads to a tiny perturbation in the dynamics of the expansion of the universe through the generalized Friedmann equations so-called the extended $\Lambda$CDM model. From the observational test standpoint, we make a Bayesian analysis of the models of bulk viscosity for dark energy which follows the Eckart theory of bulk viscosity. These models are investigated through the context of both models $\Lambda$CDM and extended $\Lambda$CDM. The Bayesian analysis is performed using the data of CMB Distance priors, Baryon Acoustic Oscillations Measurements, Cosmic Chronometers, and SNe Ia distance measurements.