A strike of luck: could the KM3-230213A event be caused by an evaporating primordial black hole?

TL;DR

This paper explores whether a primordial black hole, slowed down by quantum effects, could explain a recent ultra high energy neutrino detection, suggesting a novel dark matter candidate and testable predictions.

Contribution

It introduces the concept of memory burden slowing PBH evaporation, identifying viable parameter space for explaining the neutrino event and proposing observational tests.

Findings

Memory-burdened PBHs can have extended lifetimes, matching the event timescale.

Viable PBH parameter space consistent with dark matter constraints is identified.

Current neutrino detector configurations could test this hypothesis within a few years.

Abstract

We investigate whether the ultra high energy neutrino inferred by the recent KM3NeT observation could have originated from an evaporating black hole. Given the characteristics of black hole (BH) evaporation mechanism, any object capable of producing particles in the energy range of the detected event (around 100-800 PeV) must have a mass below 10^7 g. No known astrophysical mechanism can generate black holes of such low mass, leaving primordial black holes (PBHs)-potentially formed at the end of cosmic inflation-as the only viable candidates. Black holes with masses below 10^7 g have lifetimes shorter than 10^-5 seconds, meaning PBHs in this mass range should have fully evaporated by now. However, recent studies suggest that quantum effects, collectively referred to as the "memory burden", may slow down black hole evaporation, potentially extending the lifetimes of low-mass PBHs to timescales comparable to or exceeding the Hubble time. We systematically explore the parameter space of memory-burdened PBHs, assuming that they constitute a fraction of the dark matter (f-PBH) within current constraints, and identify viable regions that could explain the KM3-230213A event. We further predict the occurrence rate of similar events and find that KM3NeT's current configuration could test this scenario within a few years.