A measurement of the Hubble constant from Type II supernovae
  Progressive increases in the precision of the Hubble-constant measurement via
Cepheid-calibrated Type Ia supernovae (SNe Ia) have shown a discrepancy of
$\sim 4.4\sigma$ with the current value inferred from Planck satellite
measurements of the cosmic microwave background radiation and the standard
$\Lambda$CDM cosmological model. This disagreement does not appear to be due to
known systematic errors and may therefore be hinting at new fundamental
physics. Although all of the current techniques have their own merits, further
improvement in constraining the Hubble constant requires the development of as
many independent methods as possible. In this work, we use SNe II as
standardisable candles to obtain an independent measurement of the Hubble
constant. Using 7 SNe II with host-galaxy distances measured from Cepheid
variables or the tip of the red giant branch, we derive H$_0=
75.8^{+5.2}_{-4.9}$ km s$^{-1}$ Mpc$^{-1}$ (statistical errors only). Our value
favours that obtained from the conventional distance ladder (Cepheids + SNe Ia)
and exhibits a difference of 8.4 km s$^{-1}$ Mpc$^{-1}$ from the Planck
$+\Lambda$CDM value. Adding an estimate of the systematic errors (2.8 km
s$^{-1}$ Mpc$^{-1}$) changes the $\sim 1.7\sigma$ discrepancy with Planck
$+\Lambda$CDM to $\sim 1.4\sigma$. Including the systematic errors and
performing a bootstrap simulation, we confirm that the local H$_0$ value
exceeds the value from the early Universe with a confidence level of 95%. As in
this work we only exchange SNe II for SNe Ia to measure extragalactic
distances, we demonstrate that there is no evidence that SNe Ia are the source
of the H$_0$ tension.
