Using gravitational waves to hunt for dark matter

Utilizing pc simulations, a world workforce of cosmologists have found that observations of gravitational waves from merging black holes might unveil the true nature of dark matter. Their discovering can be introduced at this time on the 2023 National Astronomy Meeting by co-author Dr. Alex Jenkins of College Faculty London.

The workforce used computer simulations to review the manufacturing of gravitational wave indicators in simulated universes with totally different sorts of dark matter. Their findings present that counting the variety of black-hole merging occasions detected by the subsequent technology of observatories might inform us whether or not or not dark matter interacts with different particles, giving us new insights into what it’s made from.

Cosmologists usually regard dark matter as one of many greatest lacking items in our understanding of the cosmos. Regardless of robust proof that dark matter makes up 85% of all of the matter within the universe, there’s at the moment no consensus on its underlying nature. This consists of questions reminiscent of whether or not dark matter particles can collide with different particles reminiscent of atoms or neutrinos, or whether or not they cross straight by means of them unaffected.

A method to check that is by how galaxies type in dense clouds of dark matter referred to as haloes. If dark matter collides with neutrinos, the dark matter construction turns into dispersed, leading to fewer galaxies being shaped. The issue with this methodology is that any galaxies that go lacking are very small and really distant from us, so it is exhausting to see whether or not they’re there or not, even with the very best telescopes obtainable.

Relatively than concentrating on the lacking galaxies immediately, the authors of this examine suggest utilizing gravitational waves as an oblique measure of their abundance. Their simulations present that in fashions the place dark matter does collide with different particles, there are considerably fewer black-hole mergers within the distant universe. Whereas this impact is just too small to be seen by present gravitational wave experiments, it will likely be a first-rate goal for the subsequent technology of observatories which are at the moment being deliberate.

The authors hope their strategies will assist stimulate new concepts for utilizing gravitational wave knowledge to discover the large-scale construction of the universe, and shine a brand new mild on the mysterious nature of dark matter.

Co-author Dr. Sownak Bose of Durham College stated, “Darkish matter stays one of many enduring mysteries in our understanding of the universe. This implies it’s particularly essential to proceed figuring out new methods to discover fashions of dark matter, combining each present and new probes to check mannequin predictions to the fullest. Gravitational wave astronomy presents a pathway to higher perceive not simply dark matter, however the formation and evolution of galaxies extra usually.”

Markus Mosbech of the College of Sydney, one other co-author, provides, “Gravitational waves provide us a novel alternative to watch the early universe, as they cross unhindered by means of the universe, and next-generation interferometers can be delicate sufficient to detect particular person occasions at enormous distances.”

One other member of the analysis workforce, Professor Mairi Sakellariadou of King’s Faculty London, stated, “Third-generation gravitational wave knowledge will provide a novel and impartial method to check the present mannequin that describes the evolution of our universe, and shed mild to the but unknown nature of dark matter.”