Extended Spherical Collapse and the Accelerating Universe
  The influence of the shear stress and angular momentum on the nonlinear
spherical collapse model is discussed in the framework of the Einstein-de
Sitter (EdS) and $\Lambda$CDM models. By assuming that the vacuum component is
not clustering within the homogeneous nonspherical overdensities, we show how
the local rotation and shear affects the linear density threshold for collapse
of the non-relativistic component ($\delta_\mathrm{c}$) and its virial
overdensity ($\Delta_\mathrm{V}$). It is also found that the net effect of
shear and rotation in galactic scale is responsible for higher values of the
linear overdensity parameter as compared with the standard spherical collapse
model (no shear and rotation).
