Explaining the PeV Neutrino Fluxes at KM3NeT and IceCube with Quasi-Extremal Primordial Black Holes

TL;DR

This paper proposes that quasi-extremal primordial black holes charged under a dark U(1) symmetry can explain the high-energy neutrino fluxes observed by KM3NeT and IceCube, aligning with various astrophysical constraints.

Contribution

It introduces a novel model of charged, quasi-extremal primordial black holes that can account for PeV neutrino observations while satisfying existing astrophysical constraints.

Findings

Charged quasi-extremal primordial black holes can suppress neutrino emission at 1PeV.

The model aligns neutrino burst rates with observational data within 1 sigma.

Black holes in this model could also make up all dark matter.

Abstract

The KM3NeT experiment has recently observed a neutrino with an energy around 100PeV, and IceCube has detected five neutrinos with energies above 1PeV. While there are no known astrophysical sources, exploding primordial black holes could have produced these high-energy neutrinos. For Schwarzschild black holes this interpretation results in tensions between the burst rates inferred from the KM3NeT and IceCube observations, with indirect constraints from the extragalactic gamma ray background and with the non-observation of an associated gamma ray signal at LHAASO. In this letter we show that if there is a population of primordial black holes charged under a new dark $u(1)$ symmetry which spend most of their time in a quasi-extremal state, the neutrino emission at 1PeV may be more suppressed than at 100PeV. The burst rates implied by the KM3NeT and IceCube observations and the indirect constraints can then all be consistent at $1\sigma$, and no associated gamma-ray signal was expected at LHAASO. Furthermore, these black holes could constitute all of the observed dark matter in the universe.