Probing interaction and spatial curvature in the holographic dark energy model

Abstract

In this paper we place observational constraints on the interactionand spatial curvature in the holographic dark energy model. Weconsider three kinds of phenomenological interactions betweenholographic dark energy and matter, i.e., the interaction term Qis proportional to the energy densities of dark energy(ρΛ), matter (ρm), and matter plus dark energy(ρm+ρΛ). For probing the interaction and spatialcurvature in the holographic dark energy model, we use the latestobservational data including the type Ia supernovae (SNIa)Constitution data, the shift parameter of the cosmic microwavebackground (CMB) given by the five-year Wilkinson MicrowaveAnisotropy Probe (WMAP5) observations, and the baryon acousticoscillation (BAO) measurement from the Sloan Digital Sky Survey(SDSS). Our results show that the interaction and spatial curvaturein the holographic dark energy model are both rather small. Besides,it is interesting to find that there exists significant degeneracybetween the phenomenological interaction and the spatial curvaturein the holographic dark energy model.