Observational constraints on decaying vacuum dark energy model

TL;DR

This paper constrains a decaying vacuum dark energy model using diverse observational data, revealing a higher matter density contrast than the standard Lambda-CDM model and providing confidence contours for key parameters.

Contribution

It offers new observational constraints on the decaying vacuum dark energy model, highlighting differences from the Lambda-CDM model and presenting detailed parameter likelihoods.

Findings

Best-fit matter density contrast is much larger than in Lambda-CDM.

Confidence contours in the Ω_m-h plane are provided up to 3σ.

Normalized likelihoods for Ω_m and h are analyzed.

Abstract

The decaying vacuum model (DV), treating dark energy as a varying vacuum, has been studied well recently. The vacuum energy decays linearly with the Hubble parameter in the late-times, $\rho_\Lambda(t) \propto H(t)$, and produces the additional matter component. We constrain the parameters of the DV model using the recent data-sets from supernovae, gamma-ray bursts, baryon acoustic oscillations, CMB, the Hubble rate and x-rays in galaxy clusters. It is found that the best fit of matter density contrast $\Omega_m$ in the DV model is much lager than that in $\Lambda$CDM model. We give the confidence contours in the $\Omega_m-h$ plane up to $3\sigma$ confidence level. Besides, the normalized likelihoods of $\Omega_m$ and $h$ are presented, respectively. %