End of the cosmic neutrino energy spectrum

Understand

There may be a high-energy cutoff of neutrino events in IceCube data.

• In particular, IceCube does not observe either continuum events above 2 PeV, or the Standard Model Glashow-resonance events expected at 6.3 PeV.
• There are also no higher energy neutrino signatures in the ANITA and Auger experiments.
• This absence of high-energy neutrino events motivates a fundamental restriction on neutrino energies above a few PeV.