Coupling dark-baryonic matter density profile for vacuum decay scenarios

TL;DR

This paper investigates a cosmological model where vacuum decay influences dark matter and baryonic matter evolution, constrained by observational data on cosmic structure growth, CMB-BAO ratio, and galaxy cluster gas fractions.

Contribution

It introduces a coupled dark-baryonic matter density profile in vacuum decay scenarios and constrains the model using multiple observational datasets.

Findings

Best-fit dark matter density parameter: 0.269

Decay parameter epsilon: 0.02

Model consistent with growth rate and CMB-BAO data

Abstract

The cosmological consequences of an interacting model in which vacuum decay law is deducted from the effect that vacuum decay has on the dark matter evolution are investigated. Here, the baryonic matter is also considered as a fluid gravitationally coupled with dark matter. It is made a careful analysis to constrain this model with the observational data of growth rate of cosmic structures. The theoretical growth rate is followed since the primordial recombination and the main physical processes on the baryonic component are considered. As a complementary constraint, this model is compared with the observed CMB-BAO ratio as well with the gas mass fraction of cluster of galaxies. We found the best fit values for dark matter $\Omega_{d0} = 0.269 ^{+0.023}_{-0.023}$ and for the decay parameter $\epsilon = 0.02 ^{+0.04}_{-0.05}$.