Revisit of the interacting holographic dark energy model after Planck 2015

Abstract

We investigate the observational constraints on the interacting holographic dark energy model. We consider five typical interacting models with the interaction terms $Q=3βHρ_{\rm{de}}$, $Q=3βHρ_{\rm{c}}$, $Q=3βH(ρ_{\rm{de}}+ρ_{\rm c})$, $Q=3βH\sqrt{ρ_{\rm{de}}ρ_{\rm c}}$, and $Q=3βH\frac{ρ_{\rm{de}}ρ_{c}}{ρ_{\rm{de}}+ρ_{\rm c}}$, respectively, where $β$ is a dimensionless coupling constant. The observational data we use in this paper include the JLA compilation of type Ia supernovae data, the Planck 2015 distance priors data of cosmic microwave background observation, the baryon acoustic oscillations measurements, and the Hubble constant direct measurement. We make a comparison for these five interacting holographic dark energy models by employing the information criteria, and we find that, within the framework of holographic dark energy, the $Q=3βH\frac{ρ_{\rm{de}}ρ_{\rm c}}{ρ_{\rm{ de}}+ρ_{\rm c}}$ model is most favored by current data, and the $Q=3βHρ_{\rm c}$ model is relatively not favored by current data. For the $Q=3βHρ_{\rm{de}}$ and $Q=3βH\frac{ρ_{\rm{de}}ρ_{\rm c}}{ρ_{\rm{ de}}+ρ_{\rm c}}$ models, a positive coupling $β$ can be detected at more than 2$σ$ significance.

17 pages, 6 figures; accepted for publication in JCAP