Challenges to the cosmological constant model following results from the Dark Energy Survey

In the last year, several pieces of evidence have pointed to a possible deviation from the standard cosmological model, $\mathrm{\Lambda }$CDM. The recent work by the Dark Energy Survey (DES) collaboration reports a preference in the ballpark of $3\sigma$ in favor of dynamical dark energy against the standard cosmological model. For that, it used its final analyses of Baryonic Acoustic Oscillations and type Ia Supernovae, both sensitive to the expansion history of the Universe, in combination with the Cosmic Microwave Background (CMB) from Planck. This adds to the growing debate about the nature of dark energy. Published as a Perspective in Nature Astronomy in August 2025.