Eur. Phys. J. C 69, 509-519 (2010)
https://doi.org/10.1140/epjc/s10052-010-1408-1

Couplings between holographic dark energy and dark matter

¹ Kavli Institute for Theoretical Physics China, Institute of Theoretical Physics, Chinese Academy of Sciences, P.O. Box 2735, Beijing, 100080, China
² Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge, CB3 0HA, UK
³ National Astronomical Observatories, Chinese Academy of Sciences, Beijing, 100012, China
⁴ Graduate School of Chinese Academy of Sciences, Beijing, 100049, China

xuelei@cosmology.bao.ac.cn

Received: 3 March 2010
Revised: 8 July 2010
Published online: 14 August 2010

Abstract

We consider the interaction between dark matter and dark energy in the framework of holographic dark energy, and propose a natural and physically plausible form of interaction, in which the interacting term is proportional to the product of the powers of the dark matter and dark energy densities. We investigate the cosmic evolution in such models. The impact of the coupling on the dark matter and dark energy components may be asymmetric. While the dark energy decouples from the dark matter at late time, just as other components of the cosmic fluid become decoupled as the universe expands, interestingly, the dark matter may actually become coupled to the dark energy at late time. We shall call such a phenomenon incoupling. We use the latest type Ia supernovae data from the SCP team, baryon acoustics oscillation data from SDSS and 2dF surveys, and the position of the first peak of the CMB angular power spectrum to constrain the model. We find that the interaction term which is proportional to the first power product of the dark energy and dark matter densities gives an excellent fit to the current data.