A new study led by UC Riverside graduate student Yash Aggarwal argues that decays of dark matter could help explain very large black holes seen less than a billion years after the Big Bang. The paper appears in the Journal of Cosmology and Astroparticle Physics.
The researchers show that energy from decaying dark matter can alter the thermo-chemical state of gas in the first galaxies. These changes can allow some gas clouds to collapse directly into black holes rather than forming stars. Previously, astronomers thought direct collapse needed a rare nearby star to shine on the gas.
The team modelled the gas behaviour with decaying axions and found a window of dark matter masses between 24 and 27 electronvolts could favour direct collapse. The work involved several collaborators and received support from research funders.
Difficult words
- decay — process where a particle breaks down over timedecays, decaying
- dark matter — invisible matter that affects gravity in space
- thermo-chemical — relating to heat and chemical processes in gas
- collapse — fall together quickly into a smaller object
- axion — a hypothetical very light particle in physicsaxions
- electronvolt — unit that measures very small energy amountselectronvolts
- galaxy — a large system of stars, gas and dustgalaxies
Tip: hover, focus or tap highlighted words in the article to see quick definitions while you read or listen.
Discussion questions
- Do you think decaying dark matter is a convincing explanation for early large black holes? Why or why not?
- If some gas clouds collapse directly into black holes, how might that change the first galaxies?
- What other observations or evidence would you want to see to support this study's idea?
Related articles
Engineered bacteria produce tagatose sweetener
Tufts researchers engineered Escherichia coli to make tagatose, a rare sugar that can substitute for table sugar. They used a slime mold enzyme and another enzyme to convert glucose, producing higher yields; tagatose is low‑calorie and FDA‑recognized as safe.
Ice storm damages power systems in eastern US
A massive winter storm with ice and freezing rain is hitting the eastern United States and has cut electricity for more than a million customers. Officials, utilities and researchers are working to restore power and study grid resilience.
Study: Low numbers of women in science academies
An international analysis finds women made up about 19% of academy members in 2025, with little change in recent years. The report highlights leadership gaps, higher reports of harassment, and calls for stronger gender equality measures.
