Speaker
Description
Do neutrinos of different flavors have preferred directions of travel? If they do, it would imply a violation of Lorentz invariance, a cornerstone of modern physics. This would manifest as "flavor anisotropies"---differences in the arrival-direction distributions of astrophysical neutrinos of different flavors at Earth. In beyond-Standard-Model theories, these effects grow with neutrino energy, making TeV--PeV astrophysical neutrinos ideal probes. We search for flavor anisotropies in public IceCube data and, finding none, place constraints on hundreds of free coefficients governing Lorentz-invariance violation---many of which were previously unconstrained or only weakly constrained. As far as current observations of high-energy astrophysical neutrinos reveal, the Universe upholds Lorentz invariance.
