Revisit of the interaction between holographic dark energy and dark matter

摘要: In this paper we investigate the possible direct, non-gravitational interaction between holographic dark energy (HDE) and dark matter. Firstly, we start with two simple models with the interaction terms Q proportional to rho(dm) and Q proportional to rho(de), and then we move on to the general form Q proportional to rho(alpha)(m)rho(beta)(de). The cosmological constraints of the models are obtained from the joint analysis of the present Union 2.1+BAO+CMB+H-0 data. We find that the data slightly favor an energy flow from dark matter to dark energy, although the original HDE model still lies in the 95.4% confidence level (CL) region. For all models we find c < 1 at the 95.4% CL. We show that compared with the cosmic expansion, the effect of interaction on the evolution ofrho(dm) and rho(de) is smaller, and the relative increment (decrement) amount of the energy in the dark matter component is constrained to be less than 9% (15%) at the 95.4% CL. By introducing the interaction, we find that even when c < 1 the big rip still can be avoided due to the existence of a de Sitter solution at z -> -1. We show that this solution cannot be accomplished in the two simple models, while for the general model such a solution can be achieved with a large beta, and the big rip may be avoided at the 95.4% CL.