Relying on computational models, a global group of cosmologists has revealed that scrutinizing gravitational waves emitted from coalescing black holes could disclose the genuine essence of dark matter. These discoveries were showcased at the 2023 National Astronomy Assembly in Cardiff by collaborator Dr. Alex Jenkins from University College London. The squad utilized computational models to analyze the generation of gravitational wave signals in fictitious universes with varied forms of dark matter. Their findings suggest that the tally of black-hole fusion events detected by the forthcoming generation of observatories could disclose if dark matter interacts with other particles, granting us fresh perspectives into its composition.
Generally, cosmologists consider dark matter as one of the paramount unresolved segments in our comprehension of the universe. Although there’s compelling proof that dark matter constitutes 85% of all matter in the Universe, there’s currently no unified view on its intrinsic nature. This encompasses queries like whether dark matter particles can bump into other particles such as atoms or neutrinos, or if they merely glide through them unaffected. One method to verify this is by observing how galaxies emerge in dense clusters of dark matter termed haloes. If dark matter collides with neutrinos, the dark matter framework becomes scattered, leading to fewer galaxies being shaped. The hitch with this technique is that any galaxies that vanish are minuscule and extremely remote from us, making it challenging to ascertain whether they exist or not, even with the most advanced telescopes at hand.
Instead of directly targeting the absent galaxies, the authors of this research suggest employing gravitational waves as a secondary gauge of their profusion. Their models indicate that in scenarios where dark matter does interact with other particles, there are significantly fewer black-hole fusions in the distant cosmos. While this impact is too minute to be observed by current gravitational wave experiments, it will be a prime objective for the upcoming generation of observatories that are presently being conceptualized. The authors anticipate their methodologies will help instigate fresh concepts for utilizing gravitational wave data to examine the large-scale arrangement of the Universe, and cast new illumination on the enigmatic character of dark matter.
Contributor Dr. Sownak Bose of Durham University stated, “Dark matter continues to be one of the persistent puzzles in our understanding of the Universe. This signifies it is particularly crucial to persist in uncovering new ways to investigate models of dark matter, merging both current and novel probes to test model forecasts to the maximum. Gravitational wave astronomy presents a route to deepen our grasp not just of dark matter, but also the genesis and development of galaxies more broadly.” Markus Mosbech from the University of Sydney, another contributor, chimes in, “Gravitational waves provide us with a unique chance to observe the early Universe, as they traverse unhindered through the Universe, and next-generation interferometers will be adequately sensitive to identify individual occurrences at vast distances.” Another participant in the research team, commented, “Data from third-generation gravitational waves will offer an innovative and autonomous method to test the current model that delineates the evolution of our Universe, and shed brightness on the still undisclosed nature of dark matter.”