Constraining the dark energy models using baryon acoustic oscillations: An approach independent of H₀ ⋅ r_d

¹ Institute for Nuclear Research and Nuclear Energy, Bulgarian Academy of Sciences, Sofia, Bulgaria
e-mail: dstaicova@inrne.bas.bg
² DAMTP, Centre for Mathematical Sciences, University of Cambridge, Wilberforce Road, Cambridge CB3 0WA, UK
³ Kavli Institute of Cosmology (KICC), University of Cambridge, Madingley Road, Cambridge CB3 0HA, UK

Received: 27 June 2022
Accepted: 12 September 2022

Abstract

The H₀ tension and the accompanying r_d tension are a hot topic in current cosmology. In order to remove the degeneracy between the Hubble parameter H₀ and the sound horizon scale r_d from the baryon acoustic oscillation (BAO) datasets, we redefined the likelihood by marginalizing over the H₀ ⋅ r_d parameter and then we performed a full Bayesian analysis for different models of dark energy (DE). We find that our datasets that are uncalibrated by early or late physics cannot constrain the DE models properly without further assumptions. By adding the type Ia supernova (SNIa) dataset, the models are constrained better with smaller errors on the DE parameters. The two BAO datasets we used – one with angular measurements and one with angular and radial ones, with their covariance – show statistical preferences for different models, with the Λ cold dark matter (ΛCDM) model being the best model for one of them. Adding the Pantheon SNIa dataset with its covariance matrix boosts the statistical preference for the ΛCDM model.