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 Λ cold dark matter cosmology. In fact, on one hand coupled dark energy models are characterized by an excess of large voids in the cold dark matter distribution as compared to the reference standard cosmology, due to their higher normalization of linear perturbations at low redshifts. Specifically, these models present an excess of large voids with Reff > 20, 15, 12h−1 Mpc , at z = 0, 0.55, 1, respectively. On the other hand, we do not find any significant difference in the properties of the voids detected in the distribution of collapsed dark matter haloes. These results imply that the tracer bias has a significant impact on the possibility of using cosmic void catalogues to probe cosmology.