In the first quintillionth of a second, the universe may have generated microscopic black holes with enormous amounts of nuclear charge, MIT physicists propose.
For every kilogram of matter we can see—from your desktop computer to distant stars and galaxies—there are 5 kilograms of invisible matter permeating our environment. This “dark matter” is a mysterious entity that eludes all forms of direct observation, but makes its presence felt through its invisible attraction on visible objects.
Fifty years ago, physicist Stephen Hawking proposed an idea of what dark matter could be: a population of black holes, which could have formed very soon after the Big Bang. Those “primordial” black holes would not have been the giants we detect today, but rather microscopic regions of ultradense matter that would have formed in the first quintillionth of a second after the Big Bang and then would have collapsed and dispersed across the cosmos, pulling the surrounding space-time in ways that could explain the dark matter we know today.
Now, MIT physicists have discovered that this primordial process would have also produced some unexpected companions: even smaller black holes with unprecedented amounts of a property of nuclear physics known as “color charge.”
These smaller, “supercharged” black holes would have been a completely new state of matter, which likely evaporated a fraction of a second after their generation. However, they could still have influenced a key cosmological transition: the moment when the first atomic nuclei were forged. Physicists postulate that the color-charged black holes could have affected the balance of the merging nuclei, in a way that astronomers could one day detect with future measurements. Such an observation would convincingly point to primordial black holes as the root of all current dark matter.
“Although these exotic, short-lived creatures no longer exist today, they could have affected cosmic history in ways that could appear in subtle signals today,” David Kaiser, Germeshausen Professor of the History of Science and professor of science, says in a statement. of Physics at MIT. “Within the framework of the idea that all dark matter could be due to black holes, this gives us new elements to look for.”
The research has been published in the journal Physical Review Letters.
