Did We Just See a Black Hole Explode? Physicists at UMass Amherst Think So—and It Could Explain (Almost) Everything : UMass Amherst

So far, so theoretical.

Then, in 2023, an experiment called the KM3NeT Collaboration captured that impossible neutrino—exactly the kind of evidence the UMass Amherst team hypothesized we might soon see.

But there was a hitch: A similar experiment, called IceCube, also set up to capture high-energy cosmic neutrinos, not only didn’t register the event, it had never clocked anything with even one hundredth of its power. If the universe is relatively thick with PBHs, and they are exploding frequently, shouldn’t we be showered in high-energy neutrinos? What can explain the discrepancy?

“We think that PBHs with a ‘dark charge’—what we call quasi-extremal PBHs—are the missing link,” says Joaquim Iguaz Juan, a postdoctoral researcher in physics at UMass Amherst and one of the paper’s co-authors. The dark charge is essentially a copy of the usual electric force as we know it, but which includes a very heavy, hypothesized version of the electron, which the team calls a “dark electron.”

“There are other, simpler models of PBHs out there,” says Michael Baker, co-author and an assistant professor of physics at UMass Amherst; “our dark-charge model is more complex, which means it may provide a more accurate model of reality. What’s so cool is to see that our model can explain this otherwise unexplainable phenomenon.”

“A PBH with a dark charge,” adds Thamm, “has unique properties and behaves in ways that are different from other, simpler PBH models.  We have shown that this can provide an explanation of all of the seemingly inconsistent experimental data.”

The team is confident that, not only can their dark-charge model PBHs explain the neutrino, it can also answer the mystery of dark matter. “Observations of galaxies and the cosmic microwave background suggest that some kind of dark matter exists,” says Baker.

“If our hypothesized dark charge is true,” adds Iguaz Juan, “then we believe there could be a significant population of PBHs, which would be consistent with other astrophysical      observations, and account for all the missing dark matter in the universe.”

“Observing the high-energy neutrino was an incredible event,” Baker concludes. “It gave us a new window on the universe. But we could now be on the cusp of experimentally verifying

Hawking radiation, obtaining evidence for both primordial black holes and new particles beyond the Standard Model, and explaining the mystery of dark matter.”