DESI (the Dark Energy Spectroscopic Instrument) has measured the redshifts of tens of millions of galaxies and quasars and has built the largest threedimensional map of the cosmos ever created, allowing scientists to track how the Universe expanded over the last 10 billion years. Its measurements of cosmic expansion are now among the most precise ever achieved, providing a powerful new benchmark for testing cosmological models.
Most strikingly, DESI’s early results suggest subtle but intriguing deviations from the simplest picture of dark energy acting as a constant force: when combined with other cosmological data, the measurements hint that dark energy may evolve over time. While not yet conclusive, this possibility—if confirmed—would represent a major shift in our understanding of the physics driving cosmic acceleration.
