Reexploration of interacting holographic dark energy model: Cases of interaction term excluding the Hubble parameter

Abstract

In this paper, we make a deep analysis for the five typical interacting holographic dark energy models with the interaction terms $Q=3βH_{0}ρ_{\rm{de}}$, $Q=3βH_{0}ρ_{\rm{c}}$, $Q=3βH_{0}(ρ_{\rm{de}}+ρ_{\rm c})$, $Q=3βH_{0}\sqrt{ρ_{\rm{de}}ρ_{\rm c}}$, and $Q=3βH_{0}\frac{ρ_{\rm{de}}ρ_{c}}{ρ_{\rm{de}}+ρ_{\rm c}}$, respectively. We obtain observational constraints on these models by using the type Ia supernova data (the Joint Light-curve Analysis sample), the cosmic microwave background data (Planck 2015 distance priors), the baryon acoustic oscillations data, and the direct measurement of the Hubble constant. We find that the values of $χ_{\rm min}^2$ for all the five models are almost equal (around~699), indicating that the current observational data equally favor these IHDE models. In addition, a comparison with the cases of interaction term involving the Hubble parameter $H$ is also made.