Cosmic voids in coupled dark energy cosmologies: the impact of halo bias
  In this work we analyse the properties of cosmic voids in standard and
coupled dark energy cosmologies. Using large numerical simulations, we
investigate the effects produced by the dark energy coupling on three
statistics: the filling factor, the size distribution and the stacked profiles
of cosmic voids. We find that the bias of the tracers of the density field used
to identify the voids strongly influences the properties of the void
catalogues, and, consequently, the possibility of using the identified voids as
a probe to distinguish coupled dark energy models from the standard $\Lambda
$CDM cosmology. In fact, on one hand coupled dark energy models are
characterised by an excess of large voids in the cold dark matter distribution
as compared to the reference standard cosmology, due to their higher
normalisation of linear perturbations at low redshifts. Specifically, these
models present an excess of large voids with $R_{eff}>20, 15, 12$ Mpc h^{-1},
at $z=0, 0.55, 1$, respectively. On the other hand, we do not find any
significant difference in the properties of the void detected in the
distribution of collapsed dark matter halos. These results imply that the
tracer bias has a significant impact on the possibility of using cosmic void
catalogues to probe cosmology.
