High energy neutrino astronomy

Neutrinos are very promising probes for high energy astrophysics. Indeed, many indications suggest that cosmic objects where acceleration of charged particles takes place, e.g. GRBs and AGNs, are the sources of the detected UHECRs. Accelerated hadrons, interacting with ambient gas or radiation, can produce HE neutrinos. Contrarywise to charged particles and TeV gamma rays, neutrinos can reach the Earth from far cosmic accelerators, traveling in straight line, therefore carrying direct information on the source. Theoretical models indicate that a detection area of ≈1 km2 is required for the measurement of HE cosmic ν fluxes. The detection of Cherenkov light emitted by the secondary leptons produced by neutrino intercation in large volume transparent natural media (water or ice) is today considered the most promising experimental approach to build high energy neutrino detectors. The experimental efforts towards the opening of the high energy neutrino astronomy are also reviewed.