Fundamental physics with high-energy cosmic neutrinos today and in the future

Understand

The astrophysical neutrinos discovered by IceCube have the highest detected neutrino energies --- from TeV to PeV --- and likely travel the longest distances --- up to a few Gpc, the size of the observable Universe.

• These features make them naturally attractive probes of fundamental particle-physics properties, possibly tiny in size, at energy scales unreachable by any other means.
• The decades before the IceCube discovery saw many proposals of particle-physics studies in this direction.
• Today, those proposals have become a reality, in spite of astrophysical unknowns.