Cosmology with Void-Galaxy Correlations
  Galaxy bias, the unknown relationship between the clustering of galaxies and
the underlying dark matter density field is a major hurdle for cosmological
inference from large-scale structure. While traditional analyses focus on the
absolute clustering amplitude of high-density regions mapped out by galaxy
surveys, we propose a relative measurement that compares those to the
underdense regions, cosmic voids. On the basis of realistic mock catalogs we
demonstrate that cross correlating galaxies and voids opens up the possibility
to calibrate galaxy bias and to define a static ruler thanks to the observable
geometric nature of voids. We illustrate how the clustering of voids is related
to mass compensation and show that volume-exclusion significantly reduces the
degree of stochasticity in their spatial distribution. Extracting the
spherically averaged distribution of galaxies inside voids from their cross
correlations reveals a remarkable concordance with the mass-density profile of
voids.
