In a significant milestone, the Dark Energy Spectroscopic Instrument (DESI) has completed its 3D map of the Universe—the highest resolution of any such map yet achieved—on schedule and with more data than expected, the collaboration announced today. Analyses of DESI data from earlier runs have already produced exciting hints of new physics—namely that the Universe's dark energy, rather than being constant, might vary over time. The latest data must still be analyzed but could help definitively confirm or disprove those hints within the next couple of years.
"DESI's five-year survey has been spectacularly successful," DESI director Michael Levi of Berkeley Lab said. "The instrument performed better than anticipated. The results have been incredibly exciting. And the size and scope of the map and how quickly we've been able to execute is phenomenal. We're going to celebrate completion of the original survey and then get started on the work of churning through the data, because we're all curious about what new surprises are waiting for us."
As previously reported, Albert Einstein’s cosmological constant (lambda) implied the existence of a repulsive form of gravity. (For a more in-depth discussion of the history of the cosmological constant and its significance for dark energy, see our 2024 story.) Quantum physics holds that even the emptiest vacuum is teeming with energy in the form of “virtual” particles that wink in and out of existence, flying apart and coming together in an intricate quantum dance. This roiling sea of virtual particles could give rise to dark energy, giving the Universe a little extra push so that it can continue accelerating. The problem is that the quantum vacuum contains too much energy: roughly 10120 times too much.
source https://arstechnica.com/science/2026/04/desi-completes-its-3d-map-of-universe-right-on-schedule/