A recent study published in the Journal of Cosmology and Astroparticle Physics suggests that the matter from massive stars may transform back into dark energy during gravitational collapse, akin to a small reverse Big Bang. This conclusion stems from observations made by the Dark Energy Spectroscopic Instrument (DESI), which features 5,000 robotic eyes mounted on the Mayall telescope at Kitt Peak Observatory in the United States.
Approximately 14 billion years ago, a mysterious energy propelled an exponential expansion of the early universe, generating all known matter, according to the prevailing inflationary theory. This ancient energy shares crucial characteristics with the dark energy present in today’s universe, which constitutes about 70% of the cosmos but remains poorly understood.
Kevin Croker, lead author of the study and assistant research scientist at Arizona State University, noted, “If black holes contain dark energy, they may couple with and grow alongside the expanding universe, accelerating their growth.” Preliminary data from DESI's first year of a planned five-year study indicates a tantalizing increase in dark energy density over time, supporting the hypothesis regarding its nature.
The research team analyzed data from tens of millions of distant galaxies measured by DESI, which looks billions of years into the past to determine the universe's expansion rate with high precision. This data can also infer changes in dark energy over time.
By comparing these findings to the formation rates of black holes from massive star deaths throughout the universe's history, the researchers observed a correlation: as new black holes formed, the amount of dark energy in the universe increased accordingly.
Duncan Farrah, an associate professor of physics at the University of Hawaii and co-author of the study, stated, “Both phenomena were consistent: as new black holes formed, the amount of dark energy in the universe increased in the right manner.” This suggests a plausible link between black holes and dark energy.
This research complements a growing body of literature exploring the potential cosmological coupling in black holes. A 2023 study involving many authors of the current article reported on cosmological coupling in supermassive black holes at galactic centers, prompting further investigations into this effect across various black hole types throughout the universe.
Brian Cartwright, an astrophysicist and co-author, highlighted that the new research connects black holes to dark energy based on their formation timing, rather than their growth rates as previously studied. Notably, the majority of the relevant black holes are younger, having formed during a period of active star formation.
The next steps involve determining the locations of these black holes and their movements over the past 8 billion years, a task scientists are currently addressing.