Utilizing the Updated Gamma-Ray Bursts and Type Ia Supernovae to Constrain the Cardassian Expansion Model and Dark Energy

作者：Wei, Jun-Jie; Ma, Qing-Bo; Wu, Xue-Feng^*

来源：Advances in Astronomy, 2015, 2015: 576093.

DOI：10.1155/2015/576093

• HUBBLE-SPACE-TELESCOPE
• PEAK ENERGY
• COSMOLOGICAL PARAMETERS
• LUMINOSITY
• REDSHIFT
• UNIVERSE
• DIAGRAM
• DECELERATION
• CALIBRATION
• DISCOVERY

We update gamma-ray burst (GRB) luminosity relations among certain spectral and light-curve features with 139 GRBs. The distance modulus of 82 GRBs at z > 1.4 can be calibrated with the sample at z <= 1.4 by using the cubic spline interpolation method from the Union2.1 Type Ia supernovae (SNe Ia) set. We investigate the joint constraints on the Cardassian expansion model and dark energy with 580 Union2.1 SNe Ia sample (z < 1.4) and 82 calibrated GRBs' data (1.4 < z <= 8.2). In Lambda CDM, we find that adding 82 high-z GRBs to 580 SNe Ia significantly improves the constraint on Omega(m)-Omega(Lambda) plane. In the Cardassian expansion model, the best fit is Omega(m) = 0.24(-0.15)(+0.15) and n = 0.16(-0.52)(+0.30) (1 sigma), which is consistent with the Lambda CDM cosmology (n = 0) in the 1 sigma confidence region. We also discuss two dark energy models in which the equation of state omega(z) is parameterized as omega(z) = omega(0) and omega(z) = omega(0) + omega(1)z/(1+z), respectively. Based on our analysis, we see that our universe at higher redshift up to z = 8.2 is consistent with the concordance model within 1 sigma confidence level.

• 出版日期2015
• 单位中国科学院紫金山天文台; 南京大学; 中国科学院大学