A simplified version of generalized Chaplygin gas (GCG) as a dark energy model is studied. By using the latest 162 ESSENCE type Ia supernovae (She Ia) data, 30 high redshift She Ia data, the baryonic acoustic osci...A simplified version of generalized Chaplygin gas (GCG) as a dark energy model is studied. By using the latest 162 ESSENCE type Ia supernovae (She Ia) data, 30 high redshift She Ia data, the baryonic acoustic oscillation peak from SDSS and the CMB data from WMAP3, a strong constraint on this simplified GCG model is obtained. At the 95.4% confidence level we obtain 0.21 ≤ Ωm ≤ 0.31 and 0.994 〈 α 〈 1.0 with the best fit Ωm = 0.25 and a = 1. This best fit scenario corresponds to an accelerating universe with qo ≈-0.65 and z ≈ 0.81 (a redshiR of cosmic phase transition from deceleration to acceleration).展开更多
文摘A simplified version of generalized Chaplygin gas (GCG) as a dark energy model is studied. By using the latest 162 ESSENCE type Ia supernovae (She Ia) data, 30 high redshift She Ia data, the baryonic acoustic oscillation peak from SDSS and the CMB data from WMAP3, a strong constraint on this simplified GCG model is obtained. At the 95.4% confidence level we obtain 0.21 ≤ Ωm ≤ 0.31 and 0.994 〈 α 〈 1.0 with the best fit Ωm = 0.25 and a = 1. This best fit scenario corresponds to an accelerating universe with qo ≈-0.65 and z ≈ 0.81 (a redshiR of cosmic phase transition from deceleration to acceleration).