Neutrino anisotropy as a probe of extreme astrophysical accelerators

Abstract

We predict that neutrino sources following the matter distribution of the universe result in an anisotropy in the neutrino sky imprinted by the local large-scale structure. We calculate the level of this anisotropy and explore how it depends on the cosmological evolution of neutrino sources. We show how the level of anisotropy can be amplified when a cutoff in the neutrino spectrum is considered, introducing an effective neutrino horizon. This effect might allow for future neutrino detectors to measure a neutrino anisotropy associated with the local large-scale structure. Measurement of the level of this anisotropy along with features of the neutrino spectrum will allow observers to constrain the cosmological evolution of neutrino sources, which at ultrahigh energies (UHEs) are also expected to be the sources of UHE cosmic rays.