Evolution of Spherical Overdensity in Thawing Dark energy Models
  We study the general evolution of spherical over-densities for thawing class
of dark energy models. We model dark energy with scalar fields having canonical
as well as non-canonical kinetic energy. For non-canonical case, we consider
models where the kinetic energy is of the Born-Infeld Form. We study various
potentials like linear, inverse-square, exponential as well as PNGB-type. We
also consider the case when dark energy is homogeneous as well as the case when
it is inhomogeneous and virializes together with matter. Our study shows that
models with linear potential in particular with Born-Infeld type kinetic term
can have significant deviation from the $\Lambda$CDM model in terms of density
contrast at the time of virialization. Although our approach is a simplified
one to study the nonlinear evolution of matter overdensities inside the cluster
and is not applicable to actual physical situation, it gives some interesting
insights into the nonlinear clustering of matter in the presence of thawing
class of dark energy models.
