Abstract
It is shown that, in an isotropic three-dimensional spin glass with an axial anisotropy energy, three spin wave branches exist in the limit k to O. The two transverse branches have an identical gap in this limit while the longitudinal branch does not. The transverse branches are split by an external static field. Dispersion is initially quadratic for the transverse branches but linear for the longitudinal branch. For vanishingly small anisotropy all the branches are linear.