Black holes could be the origin and the end of the universe • Trends 21

A new theory suggests that the dark matter that formed the universe originated in primordial black holes that scattered throughout the universe. According to Navruz, black holes will also be the final destination of the universe.

A new cosmological theory could explain why dark matter dominates the universe.

Dark matter, which accounts for 80% of the entire mass of cosmic structures, is a mysterious substance that exerts gravity but does not interact with light.

According to the new theory, dark matter could consist of tiny black holes permeating the universe.

The suggestion is difficult to understand at first, because dark matter was already dominating the universe when black holes could not exist.

The new theory consists of explaining how this dark matter, which is responsible for the formation of large structures such as the cosmic web or groups of galaxies, which appeared before the formation of the first galaxies, may have something to do with holes. It does not appear in the inventory of what was there in the first moments of the universe.

Related topic: Beyond the extreme darkness of the universe hides the light

Primordial black holes

The key will be hypothetical primordial black holes, the existence of which has not yet been proven.

The authors of this study, published so far only in arXiv, Ke-Pan Xie and Kiyoharu Kawana, researchers at the Center for Theoretical Physics at Seoul University, in South Korea, propose a new view of the universe’s first moments.

In those first moments, quantum processes occurred that no longer occur today because the current universe is very different: it was originally hot and dense, today it is getting colder and less dense, so it is expanding more and more.

What the authors of this study made clear is that these changes in quantum processes did not all occur at the same time and that this time period was sufficient for a large amount of black holes The primordial ones, which are the ones that made up the dark matter that made up the universe.

new particles

They propose, as a hypothesis, that in the midst of an astonishing transformation that occurred when the universe was less than a second old, a new type of particle was trapped, and collapsed to a point so small that they became black holes. Then those black holes flooded the universe, providing the weight needed to explain dark matter, explain Astrophysicist Paul Sutter in Space magazine.

Perhaps whatever was going on at the time generated trillions of smaller black holes. These black holes can persist to this day, potentially solving the mystery of dark matter,” says Sutter.

The new theory reinforces the idea that has been talked about since 1966, when Russian scientists Yakov Borisovich Zeldovich and Igor Dmitrievich Novikov first proposed the existence of so-called primordial black holes.

They would be black holes that formed shortly after the Big Bang, when high densities and other cosmic conditions led to regions dense enough in the primordial universe to undergo gravitational collapse.

radical suggestion

In this way, primordial black holes were formed, which did not arise from the gravitational collapse of a star, but from the extreme density that the Universe had at the beginning of its expansion.

For nearly five decades, primordial black holes have been candidates for dark matter, and the new theory provides a new theoretical framework explaining how it might have happened.

This is a radical suggestion, says Sutter, “but when it comes to the physics of the early universe, and the mystery surrounding dark matter, we need some radical suggestions, along with a good dose of observations, to move forward,” he adds. ..

beginning and end?

The new study could also feed into another theory proposed by Roger Penrose in 2010, known as cyclic conformal cosmology (CCC).

According to this theory, much of the matter in the universe will at some point be drawn into supermassive black holes, which have a mass of millions or tens of billions of solar masses.

If both theories are correct, this means that the beginning and end of the universe will revolve around black holes, mysterious cosmic bodies whose role in the evolution of galaxies and the universe is not known.

reference

Primordial black holes from a cosmic phase transition: the collapse of Fermi balls. Kiyoharu Kawana, Ke-Pan Xie. arXiv: 2106.000111 [astro-ph.CO].

Top image: a runaway quasar fleeing from the central axis of its galaxy. The quasar is the visible and vital signature of a black hole. Source: NASA, ESA, and M. Chiaberge (STScI and JHU).