Quantification of 2D vs 3D BAO tension using SNIa as a redshift interpolator and test of the Etherington relation

Understand

Several studies in the literature have found a disagreement between data on Baryon Acoustic Oscillations (BAO) derived using two distinct methodologies: the two-dimensional (2D or angular) BAO, which extracts the BAO signal from the angular two-point correlation function; and the three-dimensional (3D) BAO, which also exploits the radial signal imprinted on the large-scale structure of the universe.

• This discrepancy is worrisome, since many of the points contained in these data sets are obtained from the same catalogs of tracers, so we would expect them to be consistent.
• Since BAO measurements play a pivotal role in the building of the inverse distance ladder, this mismatch impacts the discourse on the Hubble tension and the theoretical solutions to the latter.
• So far, the discrepancy between 2D and 3D BAO has been only pointed out in the context of fitting analyses of cosmological models or parametrizations that involve a concrete calibration of the comoving sound horizon at the baryon-drag epoch.