Cosmic Voids in Evolving Dark Sector Cosmologies: the High Redshift
  Universe
  We compare the evolution of voids formed under the standard cosmological
model and two alternative cosmological models. The two models are a
quintessence model ($\phi$CDM) and a Coupled Dark Matter-Dark Energy (CDE)
model, both of which have evolving and interacting dark sectors. From $N$-body
adiabatic hydrodynamical simulations of these models, we measure the statistics
and quantify the properties of voids over the redshift range $z=1.5-12$: these
include their population size, volumes, shapes and average densities. We find
that the latter property has potential as a probe of cosmology, particularly
dark energy, as significant differences in average void densities exist between
the alternative models and the standard model. We postulate that this signature
arises from an increased evacuation rate of particles out of voids, or an
earlier start to void evacuation, in the alternative models as a direct
consequence of the dynamical scalar field, which also leads to greater void
merger rates. Additionally, differences between the two alternative models are
likely due to the drag force arising from dark sector coupling, acting on dark
matter particles in our coupled model.
