Revisit of the interacting holographic dark energy model after Planck 2015

TL;DR

This paper evaluates five interacting holographic dark energy models using recent observational data, finding that one model is most favored and detecting positive coupling in some models at over 2 sigma significance.

Contribution

It provides a comparative analysis of five specific interacting holographic dark energy models with updated observational constraints after Planck 2015.

Findings

The $Q=3\beta H\frac{\rho_{\rm{de}}\rho_{\rm{c}}}{\rho_{\rm{de}}+\rho_{\rm{c}}}$ model is most favored by current data.

The $Q=3\beta H\rho_{\rm{c}}$ model is less favored.

Positive coupling $\beta$ detected at >2$\sigma$ in some models.

Abstract

We investigate the observational constraints on the interacting holographic dark energy model. We consider five typical interacting models with the interaction terms $Q=3\beta H\rho_{\rm{de}}$, $Q=3\beta H\rho_{\rm{c}}$, $Q=3\beta H(\rho_{\rm{de}}+\rho_{\rm c})$, $Q=3\beta H\sqrt{\rho_{\rm{de}}\rho_{\rm c}}$, and $Q=3\beta H\frac{\rho_{\rm{de}}\rho_{c}}{\rho_{\rm{de}}+\rho_{\rm c}}$, respectively, where $\beta$ 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 $Q=3\beta H\frac{\rho_{\rm{de}}\rho_{\rm c}}{\rho_{\rm{ de}}+\rho_{\rm c}}$ model is most favored by current data, and the $Q=3\beta H\rho_{\rm c}$ model is relatively not favored by current data. For the $Q=3\beta H\rho_{\rm{de}}$ and $Q=3\beta H\frac{\rho_{\rm{de}}\rho_{\rm c}}{\rho_{\rm{ de}}+\rho_{\rm c}}$ models, a positive coupling $\beta$ can be detected at more than 2$\sigma$ significance.