Latest cosmological constraints on Cardassian expansion models including the updated gamma-ray bursts  

作　　者：Nan Liang Pu-Xun Wu Zong-Hong Zhu 

机构地区：[1]Department of Astronomy, Beijing Normal University, Beijing 100875, China [2]Center for High Energy Physics, Peking University, Beijing 100871, China [3]Center of Nonlinear Science and Department of Physics, Ningbo University, Ningbo 315211 China

出　　处：《Research in Astronomy and Astrophysics》2011年第9期1019-1030,共12页天文和天体物理学研究（英文版）

基　　金：supported by the National Science Foundation of China underthe Distinguished Young Scholar (Grant No. 10825313);the Key Project (Grant No. 10533010);the National Basic Research Program of China (973 Program;Grant No. 2007CB815401);support by the National Natural Science Foundation of China (GrantNo. 10705055);the Foundation for the Author of National Excellent Doctoral Dissertation of China(Grant No. 200922);the Century Educational Talents Plan of Chinese Education Ministry (GrantNo. 09-0144)

摘　　要：We constrain the Cardassian expansion models from the latest observa- tions, including the updated Gamma-ray bursts （GRBs）, which are calibrated using a cosmology independent method from the Union2 compilation of type Ia supernovae （SNe Ia）. By combining the GRB data with the joint observations from the Union2 SNe Ia set, along with the results from the Cosmic Microwave Background radia- tion observation from the seven-year Wilkinson Microwave Anisotropy Probe and the baryonic acoustic oscillation observation galaxy sample from the spectroscopic Sloan Digital Sky Survey Data Release. we find significant constraints on the model oarameters of the original Cardassian model ΩM0=0.282-0.014^0.015,n=0.03-0.05^＋0.05 and n=-0.16-3.26^＋0.25,β=0.76-0.58^＋0.34 of the modified polytropic Cardassian model, which are consistent with the ACDM model in a l-or confidence region. From the reconstruction of the deceleration parameter q（z） in Cardassian models, we obtain the transition redshift ZT = 0.73 ± 0.04 for the original Cardassian model and ZT = 0.68 ± 0.04 for the modified polytropic Cardassian model.We constrain the Cardassian expansion models from the latest observa- tions, including the updated Gamma-ray bursts （GRBs）, which are calibrated using a cosmology independent method from the Union2 compilation of type Ia supernovae （SNe Ia）. By combining the GRB data with the joint observations from the Union2 SNe Ia set, along with the results from the Cosmic Microwave Background radia- tion observation from the seven-year Wilkinson Microwave Anisotropy Probe and the baryonic acoustic oscillation observation galaxy sample from the spectroscopic Sloan Digital Sky Survey Data Release. we find significant constraints on the model oarameters of the original Cardassian model ΩM0=0.282-0.014^0.015,n=0.03-0.05^＋0.05 and n=-0.16-3.26^＋0.25,β=0.76-0.58^＋0.34 of the modified polytropic Cardassian model, which are consistent with the ACDM model in a l-or confidence region. From the reconstruction of the deceleration parameter q（z） in Cardassian models, we obtain the transition redshift ZT = 0.73 ± 0.04 for the original Cardassian model and ZT = 0.68 ± 0.04 for the modified polytropic Cardassian model.

关 键 词：GAMMA-RAYS bursts -- cosmology cosmological parameters 

分 类 号：P172.3[天文地球—天文学] O153.3[理学—数学]