2024-10-29 09:45:00
Almost 14 billion years ago, right at the beginning of the Big Bang (the colossal “explosion” with which the universe was born), a mysterious energy drove an exponential expansion of the nascent universe and produced all known matter, according to inflationary theory of the universe, the most accepted. That ancient energy shared key characteristics with today’s dark energy, which is one of the greatest mysteries in science, since no one knows what it is.
The possibility that dark energy is a consequence of the creation of black holes has been examined in a new study.
The study is the work of a team that includes, among others, Kevin Croker, of Arizona State University in the city of Tempe, Gregory Tarlé, of the University of Michigan, and Duncan Farrah, of the University of Hawaii, in the United States . the three institutions.
If we ask the question “Where in the current universe is there gravity as strong as that at the beginning of the universe?”, the answer is: at the center of every black hole. It can be considered that in the case of a black hole what happened during inflation happens in reverse. And this raises the fascinating possibility that a massive star’s matter is converted back into dark energy during the gravitational collapse in which it turns into a black hole. This transformation would be like a small Big Bang played in reverse, as Tarlé explains.
In the new study, Croker, Tarlé and their colleagues provide further evidence of this possibility, based on data collected by the Dark Energy Spectroscopic Instrument (DESI). DESI is made up of 5,000 robotic “eyes” mounted on the Mayall telescope at the Kitt Peak National Observatory (United States).
If black holes had dark energy, they could accelerate the expansion of the universe, in Croker’s words. “We can’t get the details of how it’s happening, but we can see the signs that it’s happening.”
Data from the first year of DESI’s planned five-year study shows strong evidence that dark energy density has increased over time. The authors of the study argue that this provides a compelling clue in support of this idea of what dark energy is, because this increase over time coincides with the rate at which the number of black holes and their mass have increased over time.
Image captured by the Webb Space Telescope of a sector of the universe as it was 11 billion years ago. Many stars were forming in this area at that time, and some of the most massive and short-lived ones were already becoming black holes, that is, according to the new hypothesis, turning matter into dark energy. (Photo: NASA, ESA, CSA, Maria Polletta (INAF), Hervé Dole (Paris), Brenda Frye (UofA), Jordan CJ D’Silva (UWA), Anton M. Koekemoer (STScI), Jake Summers (ASU), Rogier Windhorst (ASU). CC BY)
To search for clues about the relationship between dark energy and black holes, the team used tens of millions of distant galaxies measured by DESI. The instrument observes billions of light-years away (and therefore billions of years into the past) and collects data that can be used to determine with great precision how quickly the universe is expanding. In turn, this data can be used to infer how the amount of dark energy is changing over time.
The team compared this data with the number of black holes that formed when large stars died over the history of the universe.
The researchers found that the two phenomena are consistent with each other: as new black holes formed as massive stars died, the amount of dark energy in the universe increased in the same proportion. “This makes it more plausible that black holes are the source of dark energy,” Farrah points out.
The study is titled “The temporal evolution of DESI dark energy is recovered from cosmologically coupled black holes.” And it was published in the academic journal Journal of Cosmology and Astroparticle Physics. (Fountain: NCYT by Amazings)
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