The Hubble constant from eight time-delay galaxy lenses
  We present a determination of the Hubble constant from the joint, free-form
analysis of 8 strongly, quadruply lensing systems. In the concordance
cosmology, we find $H_0 =
71.8^{+3.9}_{-3.3}\,\mathrm{km}\,\mathrm{s}^{-1}\,\mathrm{Mpc}^{-1}$ with a
precision of $4.97\%$. This is in agreement with the latest measurements from
Supernovae Type Ia and Planck observations of the cosmic microwave background.
Our precision is lower compared to these and other recent time-delay
cosmography determinations, because our modelling strategies reflect the
systematic uncertainties of lensing degeneracies. We furthermore are able to
find reasonable lensed image reconstructions by constraining to either value of
$H_0$ from local and early Universe measurements. This leads us to conclude
that current lensing constraints on $H_0$ are not strong enough to break the
"Hubble tension" problem of cosmology.
