The Cosmological Mass Varying Neutrino Model in the Late Universe

ABSTRACT The cosmological Mass Varying Neutrino (MaVaN) model is considered, where the interaction between a fermionic field and a scalar field with a Ratra–Peebles potential via a Yukawa coupling is investigated. Observational constraints on the flat and non‐flat MaVaN models, as well as on the standard model, are derived from 32 measurements using MCMC analysis. Comparison with the model using the criteria , , and shows no statistically significant improvement for MaVaN models. Deviations in the expansion history remain well below , indicating that the data alone do not provide sufficient constraining power to distinguish MaVaN models from the model. The non‐flat MaVaN model reduces the tension between the value inferred from data and Planck CMB measurement from in the framework to . The discrepancy with the SH0ES measurement of is also reduced to below , primarily due to the large uncertainties of the data.