CCAST, World Lab, Beijing 100080, Peoples R China
; Chinese Acad Sci, Inst High Energy Phys, Beijing 100049, Peoples R China
In this paper, we use the type Ia supernovae data to constrain the holographic dark energy model proposed by Li. We also apply a cosmic age test to this analysis. We consider in this paper a spatially flat Friedmann-Robertson-Walker universe with a matter component and a holographic dark energy component. The fit result shows that the case c < 1 (c=0.21) is favored, which implies that the holographic dark energy behaves as a quintom-type dark energy. Furthermore, we also perform a joint analysis of SNe+CMB+LSS to this model; the result is well improved and still upholds the quintom dark energy conclusion. The best fit results in our analysis are c=0.81, Omega(0)(m)=0.28, and h=0.65, which lead to the present equation of state of dark energy w(0)=-1.03 and the deceleration/acceleration transition redshift z(T)=0.63. Finally, an expected supernova/acceleration probe simulation using Lambda CDM as a fiducial model is performed on this model, and the result shows that the holographic dark energy model takes on c < 1 (c=0.92) even though the dark energy is indeed a cosmological constant.