The Cardassian expansion revisited: constraints from updated Hubble
  parameter measurements and Type Ia Supernovae data
  Motivated by an updated compilation of observational Hubble data (OHD) which
consist of 51 points in the redshift range 0.07<z<2.36, we study an interesting
model known as Cardassian which drives the late cosmic acceleration without a
dark energy component. Our compilation contains 31 data points measured with
the differential age method by Jimenez & Loeb, and 20 data points obtained from
clustering of galaxies. We focus on two modified Friedmann equations: the
original Cardassian (OC) expansion and the modified polytropic Cardassian
(MPC). The dimensionless Hubble, E(z), and the deceleration parameter, q(z),
are revisited in order to constraint the OC and MPC free parameters, first with
the OHD and then contrasted with modern observations of SN Ia using the
compressed and full joint-light-analysis samples. We also perform a joint
analysis using the combination OHD plus compressed JLA. Our results show that
the OC and MPC models are in agreement with the standard cosmology and
naturally introduce a cosmological-constant-like extra term in the canonical
Friedmann equation with the capability of accelerating the Universe without
dark energy.
