Can decaying vacuum elucidate the late-time dynamics of the Universe ?

Abstract

We examine the decay vacuum model with a parameter $\epsilon$ that indicates the vacuum energy decay rate. By constraining this model with cosmic microwave background radiation, baryon acoustic oscillation, type Ia supernovae and 30 H(z) cosmic chronometer data points, we find that $\epsilon=-0.0003\pm0.00024$ with the best fitted $\chi^{2}$ value slightly smaller than that in the $\Lambda$CDM model. A negative value of $\epsilon$ suggesting dark matter energy decay into vacuum energy. We also obtain the Hubble constant $H_{0}=68.05\pm0.56$ that can alleviate the current $H_{0}$ tension between the local observation by the Hubble Space Telescope and the global measurement by the Planck Satellite. Using the effective equation of state formalism, we find this model is quintessence-like.