  We apply the modified acceleration law obtained from Einstein gravity coupled
to a massive skew symmetric field, F_{\mu\nu\lambda}, to the problem of
explaining X-ray galaxy cluster masses without exotic dark matter. Utilizing
X-ray observations to fit the gas mass profile and temperature profile of the
hot intracluster medium (ICM) with King beta-models, we show that the dynamical
masses of the galaxy clusters resulting from our modified acceleration law fit
the cluster gas masses for our sample of 106 clusters without the need of
introducing a non-baryonic dark matter component. We are further able to show
for our sample of 106 clusters that the distribution of gas in the ICM as a
function of radial distance is well fit by the dynamical mass distribution
arising from our modified acceleration law without any additional dark matter
component. In previous work, we applied this theory to galaxy rotation curves
and demonstrated good fits to our sample of 101 LSB, HSB and dwarf galaxies
including 58 galaxies that were fit photometrically with the single parameter
(M/L)_{stars}. The results there were qualitatively similar to those obtained
using Milgrom's phenomenological MOND model, although the determined galaxy
masses were quantitatively different and MOND does not show a return to
Keplerian behavior at extragalactic distances. The results here are compared to
those obtained using Milgrom's phenomenological MOND model which does not fit
the X-ray galaxy cluster masses unless an auxiliary dark matter component is
included.

Astrophysics;General Relativity and Quantum Cosmology