An international group of more than 900 scientists has created the largest 3D map of the cosmos ever constructed. It’s the first measure of the expansion history of the universe with precision better than 1%.
What drives this expansion is mysterious, and scientists have linked it to something called dark energy.
“Dark energy is thought by many scientists to play a key role in cosmic acceleration, but it is not well understood,” explained a press release from the University of Texas at Dallas. “Some theorize that it is a cosmological constant – an intrinsic property of space that drives the acceleration.”
Dr. Mustapha Ishak-Boushaki, professor of physics in the School of Natural Sciences and Mathematics at the university is part of the group of researchers studying universe expansion, known as the Dark Energy Spectroscopic Instrument (DESI) collaboration. They are at “the forefront of an ambitious experiment,” to study the universe’s expansion over the past 11 billion years, said the university.
Audacy previously reported on research related to DESI in 2021. DESI is located at Kitt Peak National Observatory (KPNO) in Arizona. It gathers light from the most distant parts of the universe and scientists used this light to create a map of the cosmos and see how it evolved.
“Understanding how the universe has evolved is tied to how it ends and to one of the biggest mysteries in physics: What is behind the observation that the expansion of the universe is accelerating?” explained the university.
This week, Ishak-Boushaki and two other researchers presented analyses of the first year of data collected by the DESI experiment at a meeting of the American Physical Society in Sacramento, Calif. This data both confirmed our current understanding of the universe and also provided new hints to the underlying cause of its acceleration.
“Cosmic acceleration is problematic because it counters how gravity, which causes objects with mass to be drawn together, is observed to work in our solar system and nearby space,” the University of Texas at Dallas explained.
Currently, the leading model of the universe (Lambda-CDM) It includes both ordinary matter, a matter called cold dark matter and dark energy known as Lambda. While gravitational attraction and the different kinds of matter slow down expansion, dark energy does the opposite – it makes the expansion accelerate.
“Gravity pulls matter together, so that when we throw a ball in the air, the Earth’s gravity pulls it down toward the planet,” Ishak-Boushaki said. “But at the largest scales, the universe acts differently. It’s acting like there is something repulsive pushing the universe apart and accelerating its expansion. This is a big mystery, and we are investigating it on several fronts. Is it an unknown dark energy in the universe, or is it a modification of Albert Einstein’s theory of gravity at cosmological scales?”
He said that the team’s “results show some interesting deviations from the standard model of the universe that could indicate that dark energy is evolving over time.”
With more data, Ishak-Boushaki said researchers could find more explanations and understand more about what is causing cosmic acceleration as well as a better understanding the evolution of our universe. Per the university, DESI is “the first spectroscopic experiment to perform a fully blinded analysis,” to prevent subconscious bias.
“Dr. Ishak-Boushaki’s research and his collaboration with scientists at some 70 institutions is revealing important insights about our universe, and the results are fascinating,” said Dr. David Hyndman, dean of he School of Natural Sciences and Mathematics at the University of Texas at Dallas and the Francis S. and Maurine G. Johnson Distinguished University Chair.