New Research Links Primordial Black Holes to Dark Matter: Implications for the Early Universe and Gravitational Waves

Black holes are one of the most disturbing objects in the universe, because their gravity is so strong that even light cannot escape them, making them difficult to study.

Now, a team of researchers has taken that frustration to the next level, by showing that black holes in the early universe could be responsible for dark matter, a large percentage of the universe’s content that scientists cannot see.

Dark matter is a general term for the approximately 27% of the universe’s mass that is invisible to any man-made instruments. Instead, the existence of dark matter is discovered through its gravitational effects on other objects – for example, in galaxy clusters. There are many candidates for dark matter, including dark photons, axioms, and Large Interacting Particles (or WIMPs). However, another long-standing candidate is primordial black holes, or very small black holes from the early universe, which drift through space and are difficult to see because there is nothing significant about them. ‘ orbit them.

team research, published earlier this month in D Physical Reviewstates that the abundance of primordial black holes “will be large enough for at least one object to cross the inner solar system every decade.” Therefore, the team concluded that this flyby event would be seen as a gravitational wave.

The team’s decisions are timely; earlier this month, another team suggested that traces of dark matter may be hidden in gravitational wave data collected by the Laser Interferometer Gravitational-Wave Observatory, or LIGO.

The idea that some black holes are “primordial” refers to the idea that they were born in the earliest times of the universe, as random fluctuations caused clumps of matter to collapse into themselves, creating rather small units, without light. The black holes we see range from stellar masses (about the size of our sun and similar stars) to billions of times larger. So asteroid-sized black holes are tiny on a relative scale, but they can be much smaller – even the size of an atom.

Sarah Geller, a theoretical physicist at the University of California at Santa Cruz and one of the authors of the paper, told LiveScience that “we are not making the following claims – that primordial black holes really exist, that they are ‘ make up most or all of them. dark matter; or that they actually exist in our solar system.” Instead, the team said If so all of the above is true, it means that one such object travels through the inner solar system every one to 10 years.

With new gravitational wave discoveries occurring regularly – and LISA, the next generation gravitational wave observatory in space currently under construction – we are in exciting times for primordial black holes.