Holographic dark energy models: A comparison from the latest
  observational data
  The holographic principle of quantum gravity theory has been applied to the
dark energy (DE) problem, and so far three holographic DE models have been
proposed: the original holographic dark energy (HDE) model, the agegraphic dark
energy (ADE) model, and the holographic Ricci dark energy (RDE) model. In this
work, we perform the best-fit analysis on these three models, by using the
latest observational data including the Union+CFA3 sample of 397 Type Ia
supernovae (SNIa), the shift parameter of the cosmic microwave background (CMB)
given by the five-year Wilkinson Microwave Anisotropy Probe (WMAP5)
observations, and the baryon acoustic oscillation (BAO) measurement from the
Sloan Digital Sky Survey (SDSS). The analysis shows that for HDE,
$\chi_{min}^{2}=465.912$; for RDE, $\chi_{min}^{2}=483.130$; for ADE,
$\chi_{min}^{2}=481.694$. Among these models, HDE model can give the smallest
$\chi^2_{min}$. Besides, we also use the Bayesian evidence (BE) as a model
selection criterion to make a comparison. It is found that for HDE, ADE, and
RDE, $\Delta \ln \mathrm{BE}= -0.86$, -5.17, and -8.14, respectively. So, it
seems that the HDE model is more favored by the observational data.
