Cosmological constraints on generalized Chaplygin gas model: Markov Chain Monte Carlo approach

We use the Markov Chain Monte Carlo method to investigate a global constraints on the generalized Chaplygin gas (GCG) model as the unification of dark matter and dark energy from the latest observational data: the Constitution dataset of type supernovae Ia (SNIa,), the observational Hubble data (OHD), the cluster X-ray gas mass fraction, the baryon acoustic oscillation (BAO), and the cosmic microwave background (CMB) data. In a non-flat universe, the constraint results for GCG model are, Omega(b)h(2) = 0.0235(-0.0018)(+0.00221) (1 sigma) (+0.0028)(-0.0022) (2 sigma), Omega(k) = 0.0035(-0.0182)(+0.0172) (1 sigma) (+0.0226)(-0.0204) (2 sigma), A(s) = 0.753(-0.035)(+0.037) (1 sigma) (+0.045)(-0.044) (2 sigma), alpha = 0.043(-0.016)(+0.102) (1 sigma) (+0.0134)(-0.117) (2 sigma), and H-0 = 70.00(-2.92)(+3.25) (1 sigma) (+3.77)(-3.67) (2 sigma), which is more stringent than the previous results for constraint on GCG model parameters. Furthermore, according to the information criterion, it seems that the current observations much support ACDM model relative to the GCG model.