DES six-year results largely confirm standard cosmology, with a notable caveat on galaxy clustering

The Dark Energy Survey’s six-year analysis of 669 million galaxies finds results consistent with the standard cosmology, with both a constant dark-energy density and a time-varying version fitting the data comparably well. However, patterns in how galaxies cluster still show slight tensions with predictions, indicating the model is not complete. The study tightens expansion history constraints and paves the way for further tests with the Vera C. Rubin Observatory, aiming to clarify dark energy’s nature and whether new physics may be needed.