Decaying Dark Matter May Have Seeded the Earliest Supermassive Black Holes

by Clarence Oxford
Los Angeles CA (SPX) Apr 16, 2026
A growing mystery in astronomy is the presence of gargantuan black holes - some weighing as much as a billion suns - existing less than a billion years after the Big Bang. According to standard theory, these black holes simply should not have had enough time to grow so large. New research from the University of California, Riverside now offers a compelling explanation: decaying dark matter may have altered the chemistry of early galaxies enough to allow some of them to collapse directly into black holes rather than forming stars.

The study, led by UCR graduate student Yash Aggarwal and published in the Journal of Cosmology and Astroparticle Physics, shows that energy released from dark matter decay could supercharge a process known as direct collapse - bypassing the normal stellar formation pathway entirely.

NASA's James Webb Space Telescope has continued to observe unusually large black holes in the early universe that could have formed by direct collapse. Astronomers had previously believed this process required a coincidence of nearby stars shining onto pre-stellar gas, making it rare. The new research proposes a far more widespread trigger.

Dark matter makes up roughly 85 percent of all matter in the universe and plays a central role in galaxy formation. Aggarwal's team shows that if dark matter decays, it can leak a small amount of energy into surrounding gas and dramatically increase the rate of direct collapse events. Each decaying dark matter particle would need to inject only a tiny fraction of energy - equivalent to a billion trillionth of the energy in a single AA battery.

"Our study suggests that decaying dark matter could profoundly reshape the evolution of the first stars and galaxies, with widespread effects across the universe," Aggarwal said. "With the James Webb Space Telescope now revealing more supermassive black holes in the early universe, this mechanism may help bridge the gap between theory and observation."

Flip Tanedo, associate professor of physics and astronomy at UCR and Aggarwal's doctoral co-advisor, explained why the earliest galaxies are such sensitive environments. "The first galaxies are essentially balls of pristine hydrogen gas whose chemistry is incredibly sensitive to atomic-scale energy injection," Tanedo said. "These are the properties that we want for a dark matter detector - the signature of these 'detectors' might be the supermassive black holes that we see today."

The research team - which also included James Dent of Sam Houston State University and Tao Xu of the University of Oklahoma - modeled the thermo-chemical dynamics of early galactic gas in the presence of decaying axions. They found that a window of dark matter masses between 24 and 27 electronvolts could produce the conditions necessary to seed direct collapse black holes.

Tanedo noted that the work stemmed from interdisciplinary collaboration connecting particle physicists, cosmologists, and astrophysicists through a series of workshops focused on the big questions in their fields.

"We showed that the right dark matter environment can help make the coincidence of direct collapse black holes much more likely," he said. "In the same way, the support for interdisciplinary work helped make the coincidence leading to this work possible."

Research Report:Direct collapse black hole candidates from decaying dark matter