Constraints on the holographic dark energy model via type Ia supernovae, baryon acoustic oscillation, and WMAP7

In this paper, the holographic dark energy model, where the future event horizon is taken as an IR cutoff, is confronted by using currently available cosmic observational data sets which include type Ia supernovae, baryon acoustic oscillation, and cosmic microwave background radiation from full information of WMAP 7-yr data. Via the Markov chain Monte Carlo method, we obtain the values of model parameter c = (0.696-0.0737-0.132-0.190) (+0.0737+0.159+0.264) with 1, 2, 3 sigma regions. Therefore, one can conclude that at at least 3 sigma level the future Universe will be dominated by phantom-like dark energy. It is not consistent with positive energy condition, however this condition must be satisfied to derive the holographic bound. It implies that the current cosmic observational data points disfavor the holographic dark energy model.