Quintessence and phantoms in light of DESI 2025

Abstract

We analyse DESI BAO, CMB, and supernova data to explore the physical origin of the DESI indication for dynamical dark energy. Beyond the standard CPL parametrization, we explore truncated alternatives and quintessence models. We conclude that there is compelling evidence for dark energy to be decaying in the late universe, but the evidence for a phantom behaviour is less significant. Models without phantom behaviour are compatible with the data at the $2\sigma$ CL. Furthermore, we examine a concrete quintessence scenario with a Higgs-like potential, allowing for a direct comparison with parametrized approaches and testing its consistency with current observations. This framework enables a broader investigation of late-time cosmic evolution and reveals a $93.8\%$ preference for a future transition into an anti-de Sitter space, which may ultimately lead to a cosmological collapse of our Universe.