Can we expect an excess of cosmological neutrinos during detection of gravitational waves?
As is well recognized, the supernova explosions produce a great amount of neutrinos, thus we have a strong reason to believe that all violent cosmological events, such as supernova explosions, gamma bursts, black hole merging or neutron star merging would cause remarkable neutrino sprays into the open space. Recently, a very high-energy neutrino captured by the IceCube detector is believed to be radiated from a blazar. However, as the LIGO collaboration first observed gravitational wave caused by spiral approach and merging of two giant back holes, the IceCube did not see an excess of cosmological neutrinos. The reason may be due to that the source is too far away or the neutrino spectrum is not suitable for the IceCube facility detection or just missing by chance. In this work, following Hawking's picture, we suppose that neutrinos would be ejected from black holes as strong gravitational effects lower the potential barriers to enhance neutrino escape rate through quantum tunneling effects. We use the Dirac equation in the curved spacetime to describe the neutrino status and estimate the rejection rate. Then, we also adopt a simplified version where the effects of curved spacetime is ignored to clarify the physical picture. Our conclusion is drawn based on the numerical results and a discussion on the phenomenological consequence is presented.