Cosmological Constant or Variable Dark Energy?

Selection statics of the Akaike information criterion (AIC) model and the Bayesian information criterion (BIC) model are applied to the Λ-cold dark matter (ΛCDM) cosmological model, the constant equation of state of dark energy, w=constant, and the parametrized equation of state of dark energy, w(z)=w_₀+w_₁ z/(1+z), to determine which one is the better cosmological model to describe the evolution of the universe by combining the recent
cosmic observational data including Sne Ia, the size of baryonic acoustic oscillation (BAO) peak from SDSS, the three-year WMAP CMB shift parameter. The results show that AIC, BIC and current datasets are not powerful enough to discriminate one model from the others, though odds suggest differences between them.