Abstract
Context.In cosmological fits, it is common to fix the baryon densityωbvia the cosmic microwave background. We here constrainωbby means of a model-independent interpolation of the acoustic parameter from correlated baryonic acoustic oscillations. Aims.The proposed technique is used to alleviate the degeneracy between baryonic and dark matter abundances. Methods.We propose a model-independent Bézier parametric interpolation and applied it to intermediate-redshift data. We first interpolated the observational Hubble data to extract cosmic bounds over the (reduced) Hubble constanth0and interpolated the angular diameter distances,D(z), of the galaxy clusters, inferred from the Sunyaev-Zeldovich effect, to constrain the spatial curvature, Ωk. Through the Hubble points andD(z) determined in this way, we interpolated uncorrelated data of baryonic acoustic oscillations bounding the baryonωband total matterωmdensities, reinforcing the constraints onh0and Ωkwith the same technique. Finally, to remove the matter sector degeneracy, we obtainedωbby interpolating the acoustic parameter from correlated baryonic acoustic oscillations. Results.Monte Carlo Markov chain simulations agree at 1σconfidence level with the flat ΛCDM model and are roughly suitable at 1σwith its nonflat extension, while the Hubble constant appears in tension up to the 2σconfidence levels. Conclusions.Our method excludes very small extensions of the standard cosmological model, and on the Hubble tension side, seems to match local constraints slightly.