Mysterious Clouds May Offer More Clues About Dark Matter

The search for gravitational waves could help solve one of the other burning mysteries of the Universe: boson clouds and whether they are one of dark matter’s main competitors.

Researchers are using powerful instruments, such as the Advanced Laser Interferometer Gravitational Wave Observatory (LIGO), Advanced Virgo, and KAGRA, that detect gravitational waves – waves in space-time caused by major cosmic cataclysms – at billions of miles. light years away to locate possible boson clouds.

Boson clouds, made up of ultralight subatomic particles that are nearly impossible to detect, have been suggested as a possible source of dark matter, accounting for about 85 percent of all matter in the Universe.

Now a major new international study carried out in the LIGO-Virgo-KAGRA collaboration and co-led by researchers at the Australian National University (ANU), offers one of the best clues yet to hunt down these subatomic particles by searching for gravitational waves caused by boson clouds surrounding black holes.

Dr Lilli Sun of the ANU Center for Gravitational Astrophysics said the study was the first all-sky survey in the world designed to look for predicted gravitational waves coming from possible boson clouds near rapidly spinning black holes.

“It is almost impossible to detect these ultralight boson particles on Earth,” Sun said in a statement. Particles, if they exist, are extremely small in mass and rarely interact with other matter, which is one of the key properties dark matter appears to have. Dark matter is material that cannot be seen directly, but we do know that dark matter exists. by the effect it has on the objects that we can observe.

“But by looking for gravitational waves emitted by these clouds, we can track down these elusive boson particles and possibly crack the code for dark matter. Our searches could also allow us to rule out certain ultralight boson particles that, according to our theories, might exist.” but they really don’t. “

Sun, also a research associate at the ARC Center of Excellence for Gravitational Wave Discovery (OzGrav), said the gravitational wave detectors allowed researchers to examine the energy of rapidly spinning black holes mined by such clouds, if they exist.

“We believe that these black holes trap a large number of boson particles in their powerful gravitational field, creating a cloud that rotates with them. This delicate dance continues for millions of years and continues to generate gravitational waves that rush through space,” he said

While researchers have yet to detect gravitational waves from boson clouds, Sun said the science of gravitational waves has “opened doors that were previously closed to scientists.”

“The discoveries of gravitational waves not only provide information about mysterious compact objects in the Universe, such as black holes and neutron stars, but also allow us to search for new particles and dark matter,” he said.

“Future gravitational wave detectors will undoubtedly open up more possibilities. We will be able to go deeper into the Universe and discover more knowledge about these particles.

“For example, the discovery of boson clouds using gravitational wave detectors would provide important insights into dark matter and help advance other searches for dark matter. It would also improve our understanding of particle physics more broadly.”

“For example, the discovery of boson clouds using gravitational wave detectors would provide important insights into dark matter and help advance other searches for dark matter. It would also improve our understanding of particle physics more broadly.”

In another significant advance, the study also shed more light on the possibility that boson clouds exist in our own galaxy by taking their ages into account.

Sun said the strength of any gravitational wave depends on the age of the cloud, with older ones sending weaker signals. “The boson cloud shrinks as it loses energy by sending out gravitational waves,” she said.

“We learned that a particular type of boson cloud less than 1,000 years old is not likely to exist anywhere in our galaxy, whereas clouds up to 10 million years old are not likely to exist some 3,260 light-years from Earth.”