Despite vast improvements in the measurement of the cosmological parameters , the nature of dark energy and an accurate value of the Hubble constant ( H _ { 0 } ) in the Hubble-Lemaître law remain unknown .
To break the current impasse , it is necessary to develop as many independent techniques as possible , such as the use of Type II supernovae ( SNe II ) .
The goal of this paper is to demonstrate the utility of SNe II for deriving accurate extragalactic distances , which will be an asset for the next generation of telescopes where more-distant SNe II will be discovered .
More specifically , we present a sample from the Dark Energy Survey Supernova Program ( DES-SN ) consisting of 15 SNe II with photometric and spectroscopic information spanning a redshift range up to 0.35 .
Combining our DES SNe with publicly available samples , and using the standard candle method ( SCM ) , we construct the largest available Hubble diagram with SNe II in the Hubble flow ( 70 SNe II ) and find an observed dispersion of 0.27 mag .
We demonstrate that adding a colour term to the SN II standardisation does not reduce the scatter in the Hubble diagram .
Although SNe II are viable as distance indicators , this work points out important issues for improving their utility as independent extragalactic beacons : find new correlations , define a more standard subclass of SNe II , construct new SN II templates , and dedicate more observing time to high-redshift SNe II .
Finally , for the first time , we perform simulations to estimate the redshift-dependent distance-modulus bias due to selection effects .