A Cross-Correlation Study of High-energy Neutrinos and Tracers of
  Large-Scale Structure
  The origin of the bulk of the astrophysical neutrinos detected by the IceCube
Observatory remains a mystery. Previous source-finding analyses compare the
directions of IceCube events and individual sources in astrophysical catalogs.
The source association method is technically challenging when the number of
source candidates is much larger than the number of the observed astrophysical
neutrinos. We show that in this large source number regime, a cross-correlation
analysis of neutrino data and source catalog can instead be used to constrain
potential source populations for the high-energy astrophysical neutrinos, and
provide spatial evidence for the existence of astrophysical neutrinos. We
present an analysis of the cross-correlation of the IceCube 2010-2012
point-source data and a WISE-2MASS galaxy sample. While we find no significant
detection of cross-correlation with the publicly available neutrino dataset, we
show that, when applied to the full IceCube data, which has a longer
observation time and higher astrophysical neutrino purity, our method has
sufficient statistical power to detect a cross-correlation signal if the
neutrino sources trace the Large Scale Structure of the Universe.
