We investigate whether the latest combination of DESI DR2 baryon acoustic oscillation (BAO) measurements, cosmic microwave background (CMB) data (Planck 2018 + ACT), and Type Ia supernovae (SNe Ia) compilations (Pantheon+, Union3, and DES Y5) favor a dynamical dark energy component, and explore if such a scenario can simultaneously help resolve the Hubble tension. We contrast two frameworks: the widely used phenomenological w₀ wₐCDM model, and bimetric gravity, a fundamental modification of general relativity that naturally gives rise to phantom dark energy. The w₀ wₐCDM model is moderately preferred over ΛCDM, at the 2-4 \, σ level, when fitting DESI DR2 + CMB + SNe Ia, but it exacerbates the Hubble tension. By comparison, bimetric gravity provides a modest improvement in fit quality, at the 1 \, σ level, but, by inferring H₀ = 69. 0 0. 4 \, km/s/Mpc, it partially eases the Hubble tension, from a 5 \, σ discrepancy to a 3. 7 \, σ tension. Including locally calibrated SNe Ia brings the overall preference for the bimetric model over ΛCDM to the 2 \, σ level, comparable to that of the w₀ wₐCDM model when including the local SN Ia calibration.
Högås et al. (Fri,) studied this question.