Hunting for dark matter through gravitational waves
A study presented at the National Astronomy Meeting in Cardiff by cosmologists has revealed a new method to uncover the secrets of dark matter by observing gravitational waves produced by merging black holes.
As reported by the Royal Astronomy Society, Dr. Alex Jenkins from University College London led an international team of researchers who used computer simulations to investigate the behavior of gravitational wave signals in simulated universes with different types of dark matter.
Dark matter accounts for a staggering 85 percent of all matter in the Universe. It remains one of the greatest mysteries in cosmology. Scientists are still uncertain about its fundamental properties, including whether it interacts with other particles or passes through them unaffected. Researchers hope to shed light on these questions by studying the formation of galaxies in dense clouds of dark matter, known as haloes.
Traditionally, scientists have attempted to observe missing galaxies directly. However, these galaxies are often small and located at great distances, making them extremely challenging to detect, even with advanced telescopes. In the study presented at the meeting, the researchers proposed a novel approach, suggesting that gravitational waves could indirectly measure the abundance of missing galaxies.
The team's simulations revealed that in models where dark matter interacts with other particles, there are significantly fewer mergers between black holes in the distant universe. While this effect is currently too subtle to be observed by existing gravitational wave experiments, it will be a prime target for the next generation of observatories currently in development.
The importance of exploring new avenues to study dark matter.
Dr. Sownak Bose of Durham University, one of the co-authors, expressed the importance of exploring new avenues to study dark matter, stating, "Dark matter remains one of the enduring mysteries in our understanding of the Universe. It is crucial to continue identifying new ways to explore dark matter models and test their predictions using existing and new probes." The team hopes that by utilizing gravitational wave data, they can gain valuable insights not only into dark matter but also into the formation and evolution of galaxies.

Markus Mosbech from the University of Sydney, another co-author, highlighted the unique opportunity presented by gravitational waves, stating, "Gravitational waves allow us to observe the early Universe as they traverse it unhindered. The next-generation interferometers will be sensitive to detect individual events at immense distances."
Professor Mairi Sakellariadou of King's College London, also a member of the research team, emphasized the potential of third-generation gravitational wave data. She said, "Third-generation gravitational wave data will offer a novel and independent way to test the current model that describes the evolution of our Universe and shed light on the yet unknown nature of dark matter."
As scientists continue to explore the vast mysteries of the cosmos, using gravitational waves to hunt for dark matter presents an exciting opportunity to unlock some of the universe's most elusive secrets. The research team's findings have opened up a new frontier in our understanding of dark matter, offering hope for a brighter future in unraveling the enigmatic nature of the cosmos.