Recent research from the DESI community confirms the Standard Gravitational Model and provides clues to the evolution of dark energy based on detailed analysis of data from millions of galaxies and quasars. These results contribute significantly to the understanding that the universe is expanding at an accelerating pace. A physicist at the University of Texas at Dallas, along with an international team of researchers in the Dark Energy Spectroscopic Instrument (DESI) collaboration, is leading a multi-year mission to solve one of the biggest mysteries in astrophysics: is the universe accelerating?

Scientists have proposed competing theories to explain this phenomenon. One theory suggests that an unknown force, dark energy, is tearing galaxies apart. Another theory suggests that gravity, the force that binds objects in local systems such as our solar system, behaves differently on large cosmic scales and may need to be revised to account for accelerated expansion.

Testing theories of gravity and expansion

The DESI collaboration, which includes more than 900 scientists from more than 70 institutions, has published a new analysis addressing the second theory. The findings show that the galaxy cluster is consistent with the standard model of gravity: Albert Einstein’s theory of general relativity, which also explains how objects come under the influence of gravity and how planets orbit stars. The analysis provides the most definitive test to date of how gravity behaves on very large scales and tracks how the cosmic structure has grown over the past 11 billion years.

Groundbreaking discoveries in cosmological research

Scientists participating in the collaboration shared their findings in several papers published Nov. 19 on arXiv, an online repository of peer-reviewed scientific papers. D., professor of physics at the University of Dallas School of Life Sciences and Mathematics. Mustafa Ishak-Boushaki co-chaired the DESI task force interpreting cosmological data and is the lead author of the paper presenting a detailed analysis of the universe. cosmic scale gravity test.

“For this round of DESI results, I focused my efforts at UT Dallas on a large part of gravity analysis, which imposes constraints on how matter in the universe moves and how large-scale structures such as galaxy clusters develop,” said Ishak-Bushaki, an astrophysicist whose research career focuses on cosmology questions. “The DESI results, combined with data sets from other experiments, are consistent with general relativity operating at cosmic scales, but do not completely rule out other modified theories of gravity.”

Reaching Dark Energy and Cosmic Structures

Ishak-Bushaki plans to present his cosmology results along with other researchers on behalf of the DESI collaboration at the American Astronomical Society meeting at National Harbor in Maryland in January. The new results provide an expanded analysis of the first year of DESI data, which in April helped create the largest 3D map of the universe to date and revealed clues that dark energy may evolve over time.

“The latest analysis is also consistent with our previous findings supporting the theory that dark energy is dynamic rather than fixed, a crucial result for cosmic acceleration,” Ishak-Bushaki said.

The DESI experiment can capture light from 5,000 galaxies simultaneously. The latest analysis used data from nearly 6 million galaxies and quasars, allowing researchers to look back up to 11 billion years. DESI surpassed previous efforts spanning decades by providing the most accurate overall measurement of structure growth in the universe with just one year of data.

The latest analysis also provided new upper bounds on the mass of neutrinos, the only fundamental particles whose mass has not yet been precisely measured. The new analysis expands the possibilities of extracting more information from the data and measuring how galaxies and matter are distributed at different scales in space. As in the previous study, a technique was used that hides the result from scientists until the end and reduces unconscious bias.

The DESI experiment is currently in the fourth of its five-year study examining the sky, and researchers plan to collect data from approximately 40 million galaxies and quasars by the time the project ends. The collaboration is currently analyzing the first three years of data collected and expects to present updated measurements of dark energy and the history of the expansion of the universe at a meeting of the American Physical Society in March.

The Dark Energy Spectroscopic Instrument (DESI) was established and operates with financial support from the Department of Energy’s (DOE) Office of Science. It was installed on the 4-meter telescope of Nicholas U. Mayolla at Kitt Peak National Observatory, operated by the National Science Foundation’s (NSF) NOIRLab. The DESI experiment is overseen by the US Department of Defense’s Lawrence Berkeley National Laboratory.

DESI receives additional support from the National Energy Research Computing Center, DOE’s Office of Science. Funding was also provided by the National Science Foundation, the Council of Science and Technology Institutions of Great Britain, the Gordon and Betty Moore Foundation, the Huizing-Simons Foundation, the French Alternative Energy and Atomic Energy Commission, the National Council for the Humanities, the Mexican Science and Technologies, the Spanish Ministry of Science and Innovation and DESI. member institutions.

The DESI collaboration recognizes and respects the privilege of conducting research at I’oligam Du’ag (Kitt Peak), a place of deep cultural and spiritual significance to the Tohono O’odham Nation.