Statefinder diagnostic and $w-w^{\prime}$ analysis for interacting   polytropic gas dark energy model
  The interacting polytropic gas dark energy model is investigated from the viewpoint of statefinder diagnostic tool and $w-w^{\prime}$ analysis. The dependency of the statefinder parameters on the parameter of the model as well as the interaction parameter between dark matter and dark energy is calculated. We show that different values of the parameters of model and different values of interaction parameter result different evolutionary trajectories in $s-r$ and $w-w^{\prime}$ planes. The polytropic gas model of dark energy mimics the standard $\Lambda$CDM model at the early time. 
M. Malekjani and A. Khodam-Mohammadi
gr-qc