Cardassian Universe Constrained by Latest Observations
  Several Cardassian universe models including the original, modified
polytropic and exponential Cardassian models are constrained by the latest
Constitution Type Ia supernova data, the position of the first acoustic peak of
CMB from the five years WMAP data and the size of baryonic acoustic oscillation
peak from the SDSS data. Both the spatial flat and curved universe are studied,
and we also take account of the possible bulk viscosity of the matter fluid in
the flat universe case.
