Ultra High Energy Neutrino Event KM3-230213A as a Signal of Electroweak Vacuum Turbulence in Merging Black Hole Binaries

TL;DR

This work proposes that electroweak vacuum turbulence triggered in the strong gravitational fields between merging BBHs can nucleate true-vacuum bubbles, form microscopic black holes, and generate bursts of ultra-high-energy neutrinos via Hawking radiation, including a potential 220 PeV event like KM3-230213A. To reconcile such rare, bright events with IceCube’s non-detections, the authors adopt a Pareto (heavy-tailed) distribution for per-merger neutrino yields and integrate over BBH redshift up to $z_*=3$, deriving detection probabilities for IceCube and KM3NeT/ARCA. The model also predicts associated electromagnetic cascades from ultra-high-energy gamma rays, with gamma-ray propagation through EBL/CMB and IGMF, showing consistency with current gamma-ray measurements for spectral indices in the range $\gamma=0.3$–$0.5$. The study systematically analyzes steady-state and single-source gamma-ray fluxes, environmental reprocessing in AGN disks and other galactic-nucleus settings, and even speculates about percolation-inspired connections between vacuum dynamics and the observed luminosity distribution. Overall, this framework links BBH mergers to multi-messenger signals and motivates future joint GW-neutrino-gamma observations to test electroweak vacuum instability in strong gravity regimes.

Abstract

The recent detection of the ultra-high-energy neutrino event KM3-230213A ($\sim$220 PeV) by KM3NeT telescope poses a challenge to conventional astrophysical models, particularly in light of the absence of similar $\gtrsim$100 PeV events in IceCube data, despite its larger exposure. We propose a novel mechanism in which binary black hole mergers act as transient neutrino sources via gravitationally induced electroweak vacuum instability. In this scenario, the extreme spacetime curvature near the horizons during the final inspiral phase destabilizes the Higgs vacuum, triggering nucleation of true-vacuum bubbles. Collisions between these bubbles produce microscopic black holes that rapidly evaporate via Hawking radiation, emitting intense, short-lived bursts of neutrinos with energies exceeding 100 PeV. The resulting neutrino fluence follows a heavy-tailed distribution, allowing rare but highly luminous sources to account for events like KM3-230213A while remaining consistent with IceCube's non-detections. This framework links gravitational wave sources to ultra-high-energy neutrino production and suggests that future multi-messenger observations may detect electromagnetic signatures from microscopic black hole evaporation.

Figures (1)

• Figure 1: MFP of gamma rays due to pair production on the EBL, computed using CRPropa 3 with the model of Ref. modelEBL1. The upper panel shows the energy-dependent MFP as a function of redshift. The middle panel presents the corresponding EBL photon number density, while the lower panel displays the characteristic interaction energy $\epsilon_{\text{char}}$ at which pair production is most efficient.