Findings from worldwide cooperation provoke inquiries regarding the universe’s future

Recent findings from the global Dark Energy Spectroscopic Instrument (DESI) partnership, featuring scholars from Harvard, indicate that dark energy, often regarded as a “cosmological constant,” might be diminishing over time. This poses the possibility that the conventional model of the universe may require a revision.

The destiny of the universe revolves around the equilibrium between matter and dark energy, the force believed to be propelling the universe’s accelerated expansion. DESI monitors dark energy’s effect by analyzing the distribution of matter across the universe. The latest evaluation, employing the most extensive 3D map of our universe to date, examined dark energy’s impact over the last 11 billion years.

The outcomes, derived from the initial three years of accumulated DESI information, were revealed in a March 19 press announcement from the Lawrence Berkeley National Laboratory.

Events occurring in the very early universe have left delicate imprints in how matter is arranged, a phenomenon referred to as Baryon Acoustic Oscillations. This pattern serves as a standard ruler, with its dimensions at various epochs directly influenced by the universe’s expansion. By measuring the ruler at different distances, researchers can determine the intensity of dark energy throughout time.

By integrating data from over 14 million galaxies and quasars with results from other experiments, scientists now possess more substantial evidence that dark energy’s influence might be changing in unforeseen manners.

The Center for Astrophysics | Harvard & Smithsonian (CfA) researchers, under the leadership of Harvard Professor Daniel Eisenstein and his team, played a pivotal role in the DESI collaboration in diverse capacities, including the co-development of algorithms and simulations that contributed to the recent findings.

Cristhian Garcia Quintero is among the collaboration leaders focusing on the cosmological implications of these results. Michael Rashkovetskyi conducted calculations essential for accurate distance measurements. Claire Lamman serves as co-chair of the DESI education and public outreach committee and assisted in creating visual content for the public. Eisenstein took on the role of co-spokesperson for the collaboration from 2014 to 2020. 

DESI boasts over 900 researchers spanning more than 70 institutions globally, governed by the U.S. Department of Energy’s Berkeley Lab. The collaboration has disseminated its findings in several papers set to be uploaded to the online archive arXiv and presented at the American Physical Society’s Global Physics Summit in Anaheim, California.

In tandem with revealing its latest dark energy findings at the summit, the DESI collaboration also disclosed that its Data Release 1 is now accessible for exploration by anyone. Featuring comprehensive details on many millions of celestial bodies, this data set will facilitate a broad range of astrophysical research at CfA and beyond.

In addition to advancing DESI’s cosmological objectives, CfA researchers are leveraging the collaboration to investigate galaxy evolution, the cosmic web, and the structure of the Milky Way. The DESI survey continues each clear night, broadening its cosmic map and providing astronomers an ever-enhancing perspective of the universe’s physics.