Testing the spherical evolution of cosmic voids
  We study the spherical evolution model for voids in $\Lambda$CDM, where the
evolution of voids is governed by dark energy at an earlier time than that for
the whole universe or in overdensities. We show that the presence of dark
energy suppresses the growth of peculiar velocities, causing void
shell-crossing to occur at progressively later epochs as $\Omega_{\Lambda}$
increases. We apply the spherical model to evolve the initial conditions of
N-body simulated voids and compare the resulting final void profiles. We find
that the model is successful in tracking the evolution of voids with radii
greater than $30 h^{-1} \rm Mpc$, implying that void profiles could be used to
constrain dark energy. We find that the initial peculiar velocities of voids
play a significant role in shaping their evolution. Excluding the peculiar
velocity in the evolution model delays the time of shell crossing.
