Hubble constant difference between CMB lensing and BAO measurements

We apply a tension metric Q(UDM), the update difference in mean parameters, to understand the source of the difference in the measured Hubble constant H-0 inferred with cosmic microwave background (CMB) lensing measurements from the Planck satellite (H-0 = 67.9(-1.3)(+1.1) km/s/Mpc) and from the South Pole Telescope (H-0 = 72.0(-2.5)(+2.1) km/s/Mpc) when both are combined with baryon acoustic oscillation (BAO) measurements with priors on the baryon density (BBN). Q(UDM) isolates the relevant parameter directions for tension or concordance where the two datasets are both informative and aids in the identification of subsets of data that source the observed tension. With Q(UDM), we uncover that the difference in H-0 originates from differences between Planck lensing and BAO + BBN data, at a probability to exceed of 6.6%. Most of this mild disagreement comes from the galaxy BAO measurements parallel to the line of sight in the redshift range 0.2 < z < 0.75. The redshift dependence of the parallel BAOs pulls both the matter density Omega(m) and H-0 high in Lambda ents are combined with other cosmological datasets with much stronger Omega(m) constraints.