Cosmography: Supernovae Union2, Baryon Acoustic Oscillation,
  Observational Hubble Data and Gamma Ray Bursts
  In this paper, a parametrization describing the kinematical state of the
universe via cosmographic approach is considered, where the minimum input is
the assumption of the cosmological principle, i.e. the
Friedmann-Robertson-Walker metric. A distinguished feature is that the result
does not depend on any gravity theory and dark energy models. As a result, a
series of cosmographic parameters (deceleration parameter $q_0$, jerk parameter
$j_0$ and snap parameter $s_0$) are constrained from the cosmic observations
which include type Ia supernovae (SN) Union2, the Baryon Acoustic Oscillation
(BAO), the observational Hubble data (OHD), the high redshift Gamma ray bursts
(GRBs). By using Markov Chain Monte Carlo (MCMC) method, we find the best fit
values of cosmographic parameters in $1\sigma$ regions:
$H_0=74.299^{+4.932}_{-4.287}$, $q_0=-0.386^{+0.655}_{-0.618}$,
$j_0=-4.925^{+6.658}_{-7.297}$ and $s_0=-26.404^{+20.964}_{-9.097}$ which are
improved remarkably. The values of $q_0$ and $j_0$ are consistent with flat
$\Lambda$CDM model in $1\sigma$ region. But the value of $s_0$ of flat
$\Lambda$CDM model will go beyond the $1\sigma$ region.
