Late-time interacting cosmologies and the Hubble constant tension

Abstract

In this manuscript we reassess the potential of interacting dark matter-dark energy models in solving the Hubble constant tension. These models have been proposed but also questioned as possible solutions to the $H_0$ problem. Here we examine several interacting scenarios against cosmological observations, focusing on the important role played by the calibration of Supernovae data. In order to reassess the ability of interacting dark matter-dark energy scenarios in easing the Hubble constant tension, we systematically confront their theoretical predictions using a prior on the Supernovae Ia absolute magnitude $M_B$, which has been argued to be more robust and certainly less controversial than using a prior on the Hubble constant $H_0$. While some data combinations do not show any preference for interacting dark sectors and in some of these scenarios the clustering $\sigma_8$ tension worsens, interacting cosmologies with a dark energy equation of state $w<-1$ are preferred over the canonical $\Lambda$CDM picture even with CMB data alone and also provide values of $\sigma_8$ in perfect agreement with those from weak lensing surveys. Future cosmological surveys will test these exotic dark energy cosmologies by accurately measuring the dark energy equation of state and its putative redshift evolution.