Reconstructing the properties of dark energy from recent observations

Abstract

We explore the properties of dark energy from recent observational data, including the Gold Sne Ia, the baryonic acoustic oscillation peak from SDSS, the CMB shift parameter from WMAP3, the X-ray gas mass fraction in cluster and the Hubble parameter versus redshift. The $ΛCDM$ model with curvature and two parameterized dark energy models are studied. For the $ΛCDM$ model, we find that the flat universe is consistent with observations at the $1σ$ confidence level and a closed universe is slightly favored by these data. For two parameterized dark energy models, with the prior given on the present matter density, $Ω_{m0}$, with $Ω_{m0}=0.24$, $Ω_{m0}=0.28$ and $Ω_{m0}=0.32$, our result seems to suggest that the trend of $Ω_{m0}$ dependence for an evolving dark energy from a combination of the observational data sets is model-dependent.