%0 Journal Article %T Measurement of the Dark Matter Velocity Dispersion with Dwarf Galaxy Rotation Curves %A Bruce Hoeneisen %J International Journal of Astronomy and Astrophysics %P 363-381 %@ 2161-4725 %D 2022 %I Scientific Research Publishing %R 10.4236/ijaa.2022.124021 %X Warm dark matter has, by definition, a velocity dispersion. Let v_hms(a)=v_hms(1)/a be the root-mean-square velocity of non-relativistic warm dark matter particles in the early universe at expansion parameter a. v_hms(1) is an adiabatic invariant. We obtain v_hms(1) in the core of 11 dwarf galaxies dominated by dark matter, from their observed rotation curves, up to a rotation and relaxation correction. We obtain a mean 0.490 km/s and standard deviation 0.160 km/s, with a distribution peaked at the lower end. We apply a mild, data driven, rotation and relaxation correction that obtains the adiabatic invariant in the core of the galaxies: v_hms(1)=0.406 ± 0.069 km/s. These two small relative standard deviations justify the prediction that the adiabatic invariant v_hms(1) in the core of the galaxies is of cosmological origin if dark matter is warm. This result is in agreement with measurements of v_hms(1) based on spiral galaxy rotation curves, galaxy ultra-violet luminosity distributions, galaxy stellar mass distributions, the formation of first galaxies, reionization, and the velocity dispersion cut-off mass. %K Warm Dark Matter %K Galaxy Rotation Curves %K Dwarf Galaxies %U http://www.scirp.org/journal/PaperInformation.aspx?PaperID=122098