KM3NeT Neutrino Spurs 5th-Dimension Black Hole Theory After 35-Fold Energy Record
Updated
Updated · Scientific American · Oct 2
KM3NeT Neutrino Spurs 5th-Dimension Black Hole Theory After 35-Fold Energy Record
2 articles · Updated · Scientific American · Oct 2
Summary
A February 2023 neutrino detected by KM3NeT off Sicily remains unexplained after arriving with about 35 times the energy of any previously seen neutrino.
A Sept. 28 Physical Review D paper argues the particle may have come from a primordial black hole formed by cosmic strings and hidden in a fifth dimension, where only neutrinos—not photons—could escape.
That scenario aims to solve two puzzles at once: other instruments saw no accompanying photons, and IceCube—roughly 20 times larger than KM3NeT in early 2023—found no matching high-energy neutrino in 15 years of data.
Researchers called the idea plausible but highly speculative, with some favoring more conventional sources such as blazars or cosmogenic neutrinos from cosmic-ray collisions.
The debate matters beyond one event because primordial black holes could also bear on dark matter and early supermassive black holes, while new radio-based neutrino observatories in Greenland and a larger IceCube design may test such explanations.