The high-energy neutrino background from gamma-ray bursts

High-energy neutrinos from gamma-ray bursts (GRBs) have been expected in various scenarios. Many predictions for the prompt emission and afterglow emission were done in the pre-Swift era. In this paper, we see predictions of the high-energy neutrino emission in the Swift era. Recently, Swift has shown several novel phenomena such as flares, which allows new possibilities for the high-energy neutrino emission from GRBs. High-energy neutrino signals may be detected by future-coming large neutrino detectors such as IceCube and KM3Net. If detected, they are useful for revealing the nature of GRBs and connection between ultra-high-energy cosmic rays (UHECRs) and GRBs.