Résumé
We investigate a cosmological model inspired by hybrid inflation, where two scalar fields representing dark energy (DE) and dark matter (DM) interact through a coupling that is proportional to the DE scalar field$1/\phi$ . The strength of the coupling is governed solely by the initial condition of the scalar field,$\phi_i$ , which parametrises deviations from the standard$\Lambda$ CDM model. In this model, the scalar field tracks the behaviour of DM during matter-domination until it transitions to DE while the DM component decays quicker than standard CDM during matter-domination, and is therefore different from some interacting DM-DE models which behaves like phantom dark energy. Using Planck 2018 CMB data, DESI BAO measurements and Pantheon+ supernova observations, we find that the model allows for an increase in$H_0$that can help reduce the Hubble tension. In addition, we find that higher values of the coupling parameter are correlated with lower values of$\omega_m$ , and a mild decrease of the weak-lensing parameter$S_8$ , potentially relevant to address the$S_8$tension. Bayesian model comparison, however, reveals inconclusive results for most datasets, unless S $H_0$ ES data are included, in which case a moderate evidence in favour of the hybrid model is found.