BUFFALO, N.Y. -- Imagine the formation of a black hole and you'll probably envision a massive star running out of fuel and collapsing in on itself. Yet the chaotic conditions of the early universe may have also allowed many small black holes to form long before the first stars.
These primordial black holes have been theorized for decades and could even be ever-elusive dark matter, the invisible matter that accounts for 85% of the universe's total mass.
Still, no primordial black hole has ever been observed.
New research co-led by the University at Buffalo proposes thinking both big and small to confirm their existence, suggesting that their signatures could range from very large -- hollow planetoids in space -- to minute -- microscopic tunnels in everyday materials found on Earth, like rocks, metal and glass.
Set to be published in the December issue of Physics of the Dark Universe and available online now, the theoretical study posits that a primordial black hole trapped within a large rocky object out in the cosmos would consume its liquid core and leave it hollow. Alternatively, a faster primordial black hole might leave behind straight tunnels large enough to be visible by a microscope if passing through solid material, including material right here on Earth.
"The chances of finding these signatures are small, but searching for them would not require much resources and the potential payoff, the first evidence of a primordial black hole, would be immense," says the study's co-author, Dejan Stojkovic, PhD, professor of physics in the UB College of Arts and Sciences. "We have to think outside of the box because what has been done to find primordial black holes previously hasn't worked."
The study calculated how large a hollow planetoid could be without collapsing in on itself, and the likelihood of a primordial black hole passing through an object on Earth. (If you're worried about a primordial black hole passing through you, don't be. The study concluded it would not be fatal.)
"Because of these long odds, we have focused on solid marks that have existed for thousands, millions and even billions of years," says co-author De-Chang Dai, PhD, of National Dong Hwa University and Case Western Reserve University.
Stojkovic's work was supported by the National Science Foundation, while Dai's work by the National Science and Technology Council (Taiwan).