Observational constraints on decaying vacuum dark energy model

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. %

Comments: 7 pages, 3 figures, accepted by European Physical Journal C