A pressure parametric dark energy model
  In this paper, we propose a new pressure parametric model of the total cosmos
energy components in a spatially flat Friedmann-Robertson-Walker (FRW) universe
and then reconstruct the model into quintessence and phantom scenarios,
respectively. By constraining with the datasets of the type Ia supernova (SNe
Ia), the baryon acoustic oscillation (BAO) and the observational Hubble
parameter data(OHD), we find that $\Omega_{m0}=0.270^{+0.039}_{-0.034}$ at the
1$\sigma$ level and our universe slightly biases towards quintessence behavior.
Then we use two diagnostics including $Om(a)$ diagnostic and statefinder to
discriminate our model from the cosmology constant cold dark matter
($\Lambda$CDM) model. From $Om(a)$ diagnostic, we find that our model has a
relatively large deviation from the $\Lambda$CDM model at high redshifts and
gradually approaches the $\Lambda$CDM model at low redshifts and in the future
evolution, but they can be easily differentiated from each other at the
1$\sigma$ level all along. By the statefinder, we find that both of
quintessence case and phantom case can be well distinguished from the
$\Lambda$CDM model and will gradually deviate from each other. Finally, we
discuss the fate of universe evolution (named the rip analysis) for the phantom
case of our model and find that the universe will run into a little rip stage.
