A high-energy neutrino detected by an underwater observatory in February 2025 may provide the first real evidence supporting one of Stephen Hawking’s most famous black hole theories. The KM3NeT collaboration, a network of deep-sea detectors located off the coasts of France, Italy, and Greece, registered a 100 PeV neutrino, an incredibly energetic particle that has left physicists searching for an explanation.
A new study, published on arXiv in February 2025, proposes that this neutrino may have been produced by an exploding primordial black hole, a concept Hawking first theorized five decades ago. If confirmed, this could revolutionize our understanding of black holes, dark matter, and the origins of the universe.
The research, currently under review, suggests that the neutrino could be a signature of Hawking radiation, a process in which black holes slowly lose energy over time. This supports Hawking’s idea that small black holes from the Big Bang could still exist today and eventually “evaporate” in a burst of high-energy particles.
Hawking Radiation and the Mystery of Primordial Black Holes
In the 1970s, Stephen Hawking proposed that black holes are not completely black but instead emit a faint stream of energy due to quantum effects at their event horizons. Over billions of years, this Hawking radiation should cause black holes to shrink and eventually disappear. However, no direct evidence for this process has ever been observed—until now.
The neutrino detected by KM3NeT is far more energetic than anything produced by human-made particle accelerators, raising the question: What could create such a powerful particle?
The new study suggests that it could have come from a primordial black hole, a theoretical type of black hole formed during the chaotic conditions of the early universe. These black holes, much smaller than those formed by collapsing stars, would have gradually shrunk over time until they exploded in a burst of radiation and high-energy particles—exactly the kind of event that could explain the detected neutrino.
However, there’s a problem: a primordial black hole of this size—about 22,000 pounds (10,000 kg), the weight of two elephants—should not have survived since the Big Bang. The new study introduces a possible solution, suggesting that an unknown quantum mechanism, called “memory burden,” could slow down black hole evaporation, allowing them to survive for billions of years before exploding.
Could Primordial Black Holes Explain Dark Matter?
Primordial black holes have long been considered a potential candidate for dark matter, the mysterious invisible substance that makes up about 85% of the universe’s total mass. If these ancient black holes still exist and are evaporating as predicted, then we should expect more high-energy neutrinos to be detected in the coming years.
The researchers calculated that if primordial black holes truly account for dark matter, then KM3NeT and other neutrino detectors like IceCube in Antarctica should observe similar high-energy events at least once every few years.
If another neutrino of this type is detected soon, it could mean a major breakthrough in both astrophysics and cosmology—potentially proving the existence of Hawking radiation, primordial black holes, and their role in the universe’s evolution.
