Science News

New research links black holes to dark energy

By Doug Cunningham   |   Feb. 15, 2023 at 4:05 PM
In published papers, researchers from the University of Hawaii at Manoa say they've found the first proposed astrophysical source for dark energy. It's a phenomenon known as "cosmological coupling" in which black holes couple with the evolving universe. Pictured is the first image of a black hole released on April 10, 2019, captured using Event Horizon Telescope observations of the center of the galaxy M87. NASA/UPI

Feb. 15 (UPI) -- For the first time, scientists have uncovered evidence of "cosmological coupling," linking black holes to dark energy.

Researchers at the University of Hawaii at Manoa sifted through 9 billion years of data to make the finding. In two published studies, astrophysicists Duncan Farrah and Kevin Croker combined their expertise with observations of researchers worldwide to reveal what might exist inside black holes.


They say they've found the first evidence of "cosmological coupling," a newly predicted phenomenon in Einstein's theory of gravity that's possible only when black holes exist inside an evolving universe.

Cosmological coupling, according to the researchers, is when black holes couple, or connect, to the expanding universe.

"We're really saying two things at once," lead author Farrah said. "That there's evidence the typical black hole solutions don't work for you on a long, long timescale, and we have the first proposed astrophysical source for dark energy."

In the paper published in The Astrophysical Journal Letters the researchers wrote, "We find evidence for cosmologically coupled mass growth among these black holes, with zero cosmological coupling excluded at 99.98% confidence ... we, thus, propose that stellar remnant black holes are the astrophysical origin of dark energy ...."

The researchers found that growth in the mass of black holes seem to correlate with predictions for black holes that cosmologically couple but also contain vacuum energy.

Farrah and Croker said the research also showed black holes gaining mass across billions of years that can't be explained by currently known black hole processes.

Since black holes come from dead stars, the research team found that if you can determine how many large stars are being made, you can also estimate the number of black holes and how much they grow through cosmological coupling.