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 $\mathrm{SNe}+\mathrm{CMB}+\mathrm{LSS}$ to this model; the result is well improved and still upholds the quintom dark energy conclusion. The best fit results in our analysis are $c=0.81$, ${\Omega }_m^0=0.28$, 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 $\Lambda \mathrm{CDM}$ 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.

• Received 6 June 2005

DOI:https://doi.org/10.1103/PhysRevD.72.043524