Latest Cosmological Constraints on Cardassian expansion models including
  the updated Gamma-ray bursts
  In this paper, we constrain the Cardassian expansion models from the latest
observations including the updated Gamma-ray bursts (GRBs), which calibrated
cosmology-independently from the Union2 compilation of type Ia supernovae (SNe
Ia). By combining the GRB data to the joint observations with the Union2 SNe Ia
set, along with the Cosmic Microwave Background radiation observation from the
seven-year Wilkinson Microwave Anisotropy Probe result, the baryonic acoustic
oscillation observation from the spectroscopic Sloan Digital Sky Survey Data
Release galaxy sample, we find significant constraints on model parameters of
the original Cardassian model $\Omega_{{\rm M0}}=0.282_{-0.014}^{+0.015}$, $n=
0.03_{-0.05}^{+0.05}$; and $n= -0.16_{-3.26}^{+0.25}$,
$\beta=0.76_{-0.58}^{+0.34}$ of the modified polytropic Cardassian model, which
are consistent with the $\Lambda$CDM model in 1-$\sigma$ confidence region.
From the reconstruction of the deceleration parameter $q(z)$ in Cardassian
models, we obtain the transition redshift $z_{\rm T}=0.73\pm{0.04}$ for the
original Cardassian model, and $z_{\rm\rm T}=0.68\pm{0.04}$ for the modified
polytropic Cardassian model.
