Title: On the origin of high-energy cosmic neutrinos
Abstract: Recently, the IceCube collaboration made a big announcement of the first discovery of high-energy cosmic neutrinos. Their origin is a new interesting mystery in astroparticle physics. The present multimessenger data may give us hints of connection to cosmic-ray and/or gamma-ray sources. We look over possible scenarios for the cosmic neutrino signal, and emphasize the importance of multimessenger approaches in identifying the PeV neutrino sources and obtaining crucial clues to the cosmic-ray origin. We also discuss some possibilities to study neutrino properties and probe new physics.