A groundbreaking study using data from the Dark Energy Spectroscopic Instrument (DESI) has unveiled a bold new theory that black holes could be converting matter into dark energy, the mysterious force accelerating the expansion of the universe.

Photo details, The Dark Energy Spectroscopic Instrument is mounted on the U.S. National Science Foundation's Nicholas U. Mayall 4-meter Telescope at Kitt Peak National Observatory - a program of NSF NOIRLab - in Arizona. Credit: KPNO/NOIRLab/NSF/AURA/B. Tafreshi (Used under a CC BY 4.0 license)

DESI is an international experiment that brings together more than 900 researchers from over 70 institutions. The project is led by Lawrence Berkeley National Laboratory, and the instrument was constructed and is operated with funding from the U.S. Department of Energy Office of Science.

What can Black Holes tell us about dark energy?

Researchers at Durham University and collaborators have combined DESI's data with observations of the cosmic microwave background (CMB) to construct a new way of understanding the components of our universe.

In the new model, stars collapsing into black holes trigger a process that gradually transforms matter into dark energy. This transformation is linked to the cosmic star formation rate, allowing the model to naturally evolve over time and match both early- and late-universe observations.

The new study follows recent findings by DESI which suggest that dark energy's influence on the universe - long believed to be constant in time - is actually changing. It proposes that black holes may be the engines behind the universe's mysterious dark energy - while also shedding light on the elusive mass of fundamental particles known as neutrinos.

The new findings stem from an isolated mountain in southern Arizona called Iolkam Du'ag. Here, the Tohono O'odham Nation stewards Kitt Peak National Observatory, where the Dark Energy Spectroscopic Instrument peers deep into the universe's past using 5,000 robotic eyes - each focused on a different galaxy, switching to new ones every 15 minutes.

A major focus of the study is the mass of fundamental particles called neutrinos, the second-most abundant particle in the universe. Scientists know these particles have masses that are greater than zero and so contribute to the amount of matter in the universe, but their exact values have yet to be measured.

When DESI's data are interpreted with the current best model of the universe (in which the dark energy is constant), the matter budget is too small and leaves no room for the neutrinos. This mismatch suggests that the mass of neutrinos is negative, contradicting what scientists already know about neutrinos.

Scientists from Durham University, led by Dr Willem Elbers, proposed in a paper last year that the evolution of dark energy could be responsible for the mismatch in the neutrino masses. This new study presents a concrete model that brings the neutrino mass back into a positive value, in agreement with known physics.

These new findings, led by the University of Michigan and published in the Physical Review Letters, could resolve several long-standing puzzles in cosmology and reshape our understanding of the universe's evolution.

Dr Willem Elbers, from Durham's Department of Physics, co-chair of DESI's Cosmological Parameter Estimation group, and contributor to the research, said: "The conversion of matter into dark energy is an intriguing mechanism. It could explain a number of puzzling findings in cosmology.

"With more data and study, we may yet rule out this specific model or develop it further into a mature theory of the cosmos."

Durham is a key partner in the DESI project, having designed and built the telescope instrument's fibre-optic system which allows light from 5,000 objects at a time, such as distant galaxies, quasars and stars, to be collected simultaneously with great precision.

To date, DESI has already mapped over 40 million galaxies. Durham researchers were also in...