Are the laws of physics truly the same everywhere in the universe? This fundamental principle, known as Lorentz invariance, lies at the heart of Einstein’s theory of relativity. Yet some theories that seek to reconcile gravity with quantum physics suggest that it might not always hold. To investigate this possibility, researchers from the international KM3NeT collaboration analyzed 5,828 atmospheric neutrino candidate events detected by KM3NeT/ORCA, a neutrino telescope located deep in the Mediterranean Sea.

They found no evidence of a violation, but were able to set new experimental limits on how large such effects could be, including the first direct constraints on certain possible differences in the behavior of muon and tau neutrinos. The results are published in the Journal of Cosmology and Astroparticle Physics.