Cosmological constraints on the variable modified Chaplygin gas model by using MCMC approach

We investigate the cosmological constraints on the variable modified Chaplygin gas (VMCG) model from the latest observational data: Union2 dataset of Type Ia supernovae (SNIa), the observational Hubble data (OHD), the baryon acoustic oscillations (BAO) and the cosmic microwave background (CMB) data. By using the Markov chain Monte Carlo (MCMC) method, we obtain the mean values of parameters in the flat model: Omega(b)h(2) = 0.02257(-0.00055)(+0.00054) (1 sigma)(-0.00108)(+0.00111) (2 sigma), B-s = 0.6701(-0.0757)(+0.3299) (1 sigma)(-0.3810)(+0.3299) (2 sigma), alpha = -0.0254(-0.3339)(+0.1628) (1 sigma)(-0.7355)(+1.1101) (2 sigma), n = -0.3118(-0.9920)(+0.9759) (1 sigma)(-1.5448)(+2.5036) (2 sigma), A =0.00217(-0.00229)(+0.00232) (1 sigma)(-0.00499)(+0.00425) (2 sigma), Omega(m) = 0.2502 (+0.0124)(-0.0122) (1 sigma)(-0.0229)(+0.0250) (2 sigma) and H-0 = 71.466(-1.818)(+1.793) (1 sigma)(-3.490)(+3.565) (2 sigma). Furthermore, we investigate the thermodynamical properties of VMCG model at apparent horizon, event horizon and particle horizon respectively.