Models of vacuum energy interacting with cold dark matter: Constraints and comparison

Hai-Li Li, Lu Feng, Jing-Fei Zhang, Xin Zhang

Published 2018-12-02Version 1

In this paper, we investigate the observational constraints on the models of vacuum energy interacting with cold dark matter. We consider eight typical interaction forms, i.e., $Q=\beta H_{0}\rho_{\rm{vac}}$, $Q=\beta H_{0}\rho_{\rm{c}}$, $Q=\beta H_{0}(\rho_{\rm{vac}}+\rho_{\rm c})$, $Q=\beta H_{0}\frac{\rho_{\rm{vac}}\rho_{c}}{\rho_{\rm{vac}}+\rho_{\rm c}}$, $Q=\beta H\rho_{\rm{vac}}$, $Q=\beta H\rho_{\rm{c}}$, $Q=\beta H(\rho_{\rm{vac}}+\rho_{\rm c})$, and $Q=\beta H\frac{\rho_{\rm{vac}}\rho_{c}}{\rho_{\rm{vac}}+\rho_{\rm c}}$. The observational data used in this work to constrain these models include the JLA sample of type Ia supernovae observation, the Planck 2015 distance priors data of cosmic microwave background anisotropies observation, the baryon acoustic oscillations data, and the Hubble constant direct measurement. We find that the current observational data almost equally favor these interacting vacuum energy models. We also find that for all these I$\Lambda$CDM models the case of $\beta=0$ is actually well consistent with the current observational data within 1$\sigma$ range.