Black holes, these cosmic giants long considered simple gravitational wells, could hold the key to accelerated expansion of our Universe. An international team of astrophysicists proposes a new hypothesis linking these celestial bodies to enigmatic dark energy, a hypothetical form of energy that uniformly fills our entire cosmos and accelerates its expansion. Their work were published in the journal Journal of Cosmology and Astroparticle Physics on October 28.
Black holes, unsuspected architects of cosmic expansion
Imagine a balloon that inflates faster and faster, without more air being injected into it. This is precisely what intrigues scientists on the scale of our universe. According to known physical laws, its expansion should slow down under the influence of gravity. However, the opposite is happening.. Even more surprising, this expansion is accelerating, defying established physical models that predicted its gradual slowdown.
Kevin Croker, an astrophysicist at Arizona State University, suggests that black holes are at the origin of this astonishing phenomenon. “ If black holes contain dark energy, they can couple with the expansion of the universe and grow with it, thereby accelerating its growth. We can’t yet understand in detail how this happens, but we have evidence that it happens “. Scientists don’t yet fully understand what dark energy is, but we do know that it makes up about 70% of the total energy in the Universe.
Black holes, matter converters
At the heart of this theory lies the concept of “ cosmological coupling “. Gregory Tarlé, a physicist at the University of Michigan, suggests this analogy to better understand this phenomenon: like a film being played in reverse, the matter of a dying star plunging into a black hole would turn into dark energy. “ Perhaps cosmic inflation works in reverse: the matter of a massive star transforms into dark energy as it collapses – like a reverse Big Bang » explains the researcher.
This hypothesis would explain another mystery: the “ missing material » of the Universe. Researchers have observed this phenomenon in dead galaxies, where supermassive black holes continue to grow even though they no longer engulf visible matter. It’s as if these cosmic giants are creating their own fuel from the very fabric of space.
Convincing empirical evidence
The research team used the Dark Energy Spectroscopic Instrument (an instrument specifically designed to study dark energy) to to analyze the formation of black holes resulting from the collapse of massive stars. Duncan Farrah, from the University of Hawaii, emphasizes the consistency of the observations: “ As soon as new black holes formed when massive stars died, the amount of dark energy in the Universe logically increased. This makes the idea that black holes are the origin of dark energy much more credible “.
The measurements carried out by the team of researchers seem to confirm this hypothesis. When astronomers do the math, they discover that the amount of ordinary matter that appears to be missing from the universe perfectly matches the amount of dark energy that appears. This mathematical correspondence is not a simple coincidence. Black holes would act like giganticcosmic factories : they swallow ordinary matter – stars, gas, dust – and transform it into dark energy by a process which remains unknown at the moment.
This new theory therefore entrusts a completely new role to black holes. If these hypotheses are confirmed by future research, they could profoundly reshape our understanding of modern cosmology, by integrating black holes into the model of the evolution of the Universe. So far, they were not considered direct contributors to cosmic expansionbut rather like celestial bodies influencing their immediate environment (galaxies, stars, etc.) through their extreme gravity and their ability to swallow matter and light.
- Black holes could contribute to the accelerated expansion of the Universe by producing dark energy.
- Matter absorbed by black holes would transform into dark energy, stimulating the growth of the Universe.
- If confirmed, this hypothesis would redefine the role of black holes in the cosmological model.
