Multi-messenger Constraints on a Primordial Black Hole Origin of the KM3-230213A Event

Abstract

Black holes are expected to end their lifetime in a burst of Hawking radiation, emitting all Standard Model particles at ultra-high energies. The evaporation of a nearby primordial black hole (PBH) has been proposed as an explanation for the high-energy neutrino-like event reported by KM3NeT. Such a scenario requires the source to be extremely close to Earth, implying detectable gamma-ray and cosmic-ray emission. Accounting for the time-dependent field of view of gamma-ray observatories, we find that current experiments should have observed a pre-burst signal, while neutrino telescopes would also detect lower-energy events before the burst. The absence of such multimessenger signals strongly disfavors a PBH origin of the KM3-230213A event in the minimal 4D Schwarzschild scenario.

Comments: Contribution to the 2026 Very High Energy Phenomena in the Universe session of the 60th Rencontres de Moriond. Included determination of DM fraction compatible with the KM3NeT event in a diffuse PBH population scenario