Voids in the SDSS: from demography to cosmology

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Cosmic voids are potentially a rich source of information
for both astrophysics and cosmology. To enable such science, we produce the
most comprehensive void catalog to date using the Sloan Digital Sky Survey Data
Release 7 main sample out to redshift z = 0.2 and the Luminous Red Galaxy
sample out to z = 0.44. Using a modified version of the parameter-free void
finder ZOBOV, we fully take into account the presence of survey boundary and
masks. We discuss basic catalog statistics such as number counts and redshift
distributions, as well as describe some example data products derived from our
catalog, such as radial density profiles and projected density maps. Using this
catalog, we report on the first application of the Alcock-Paczynski test to
stacked voids in spectroscopic redshift surveys by applying the shape-fitting
procedure presented in Lavaux & Wandelt (2011) to ten void stacks out to
redshift z = 0.36. Our results are consistent with WMAP 7-year cosmological
constraints. We compare our results to alternate methods of constructing void
stacks and comment on future observational prospects.