Holographic dark energy in a universe with spatial curvature and massive neutrinos: a full Markov Chain Monte Carlo exploration

Abstract

In this paper, we report the results of constraining the holographicdark energy model with spatial curvature and massive neutrinos,based on a Markov Chain Monte Carlo global fit technique. The cosmicobservational data include the full WMAP 7-yr temperature andpolarization data, the type Ia supernova data from Union2.1 sample,the baryon acoustic oscillation data from SDSS DR7 and WiggleZ DarkEnergy Survey, and the latest measurements of H0 from HST. Todeal with the perturbations of dark energy, we adopt theparameterized post-Friedmann method. We find that, for the simplestholographic dark energy model without spatial curvature and massiveneutrinos, the phenomenological parameter c < 1 at more than4σ confidence level. The inclusion of spatial curvatureenlarges the error bars and leads to c < 1 only in about 2.5σrange; in contrast, the inclusion of massive neutrinos does not havesignificant influence on c. We also find that, for the holographicdark energy model with spatial curvature but without massiveneutrinos, the 3σ error bars of the current fractionalcurvature density Ωk0 are still in order of 10−2; forthe model with massive neutrinos but without spatial curvature, the2σ upper bound of the total mass of neutrinos is ∑mν < 0.48 eV. Moreover, there exists clear degeneracy betweenspatial curvature and massive neutrinos in the holographic darkenergy model, which enlarges the upper bound of ∑mν bymore than 2 times. In addition, we demonstrate that, making use ofthe full WMAP data can give better constraints on the holographicdark energy model, compared with the case using the WMAP ``distancepriors''.