Scalar field descriptions of two dark energy models
  We give a scalar field description of two dark energy parameterizations, and
we analyze in detail its cosmology both at the level of background evolution
and at the level of linear perturbations. In particular, we compute the
statefinder parameters and the growth index as functions of the red-shift for
both dark energy parameterizations, and the comparison with the $\Lambda CDM$
model as well as with a few well-known geometrical dark energy models is shown.
In addition, the combination parameter $A=f \sigma_8$ of both models is
compared against current data.
