Exploring the H0 tension and the evidence for dark sector interactions from 2D BAO measurements

Abstract

We explore observational constraints on a cosmological model with an interaction between dark energy (DE) and dark matter (DM), using a compilation of 15 measurements of the 2D baryon acoustic oscillation (BAO) (i.e., transversal) scale in combination with Planck-CMB data, to explore the parametric space of a class of interacting DE (IDE) models. We find that 2D BAO measurements can generate different observational constraints compared to the traditional approach of studying the matter clustering in the 3D BAO measurements. Contrary to the observations for the $\mathrm{\ensuremath{\Lambda}}\mathrm{CDM}$ and IDE models when analyzed with $\mathrm{Planck}\text{\ensuremath{-}}\mathrm{CMB}+3\mathrm{D}$ BAO data, we note that $\mathrm{Planck}\text{\ensuremath{-}}\mathrm{CMB}+2\mathrm{D}$ BAO data favor high values of the Hubble constant ${H}_{0}$. From the joint analysis with $\mathrm{Planck}\text{\ensuremath{-}}\mathrm{CMB}+2\mathrm{D}$ $\mathrm{BAO}+\text{Gaussian}$ prior on ${H}_{0}$, we find ${H}_{0}=73.4\ifmmode\pm\else\textpm\fi{}0.88\text{ }\text{ }\mathrm{km}/\mathrm{s}/\mathrm{Mpc}$. We conclude that the ${H}_{0}$ tension is solved in the IDE model with strong statistical evidence (more than $3\ensuremath{\sigma}$) for the IDE cosmologies.