The darkness that shaped the void: dark energy and cosmic voids
  Aims: We assess the sensitivity of void shapes to the nature of dark energy
that was pointed out in recent studies. We investigate whether or not void
shapes are useable as an observational probe in galaxy redshift surveys. We
focus on the evolution of the mean void ellipticity and its underlying physical
cause. Methods: We analyse the morphological properties of voids in five sets
of cosmological N-body simulations, each with a different nature of dark
energy. Comparing voids in the dark matter distribution to those in the halo
population, we address the question of whether galaxy redshift surveys yield
sufficiently accurate void morphologies. Voids are identified using the
parameter free Watershed Void Finder. The effect of redshift distortions is
investigated as well. Results: We confirm the statistically significant
sensitivity of voids in the dark matter distribution. We identify the level of
clustering as measured by \sigma_8(z) as the main cause of differences in mean
void shape <\epsilon>. We find that in the halo and/or galaxy distribution it
is practically unfeasible to distinguish at a statistically significant level
between the various cosmologies due to the sparsity and spatial bias of the
sample.
