The Hubble Tension Revisited: Additional Local Distance Ladder
  Uncertainties
  In a recent paper, we argued that systematic uncertainties related to the
choice of Cepheid color-luminosity calibration may have a large influence on
the tension between the Hubble constant as inferred from distances to Type Ia
supernovae and the cosmic microwave background as measured with the Planck
satellite. Here, we investigate the impact of other sources of uncertainty in
the supernova distance ladder, including Cepheid temperature and metallicity
variations, supernova magnitudes and GAIA parallax distances. Excluding Milky
Way Cepheids based on parallax calibration uncertainties, for the color excess
calibration we obtain $H_0 = 70.8\pm 2.1$ km/s/Mpc, in $1.6\,\sigma$ tension
with the Planck value.
