Equivalence of measures of smoothness in , 1 < p < ∞
Suppose Δ̃ is the Laplace-Beltrami operator on the sphere and where ρ ∈ SO(d). Then and are equivalent for 1 < p < ∞. We note that for even m the relation was recently investigated by the second author. The equivalence yields an extension of the results on sharp Jackson inequalities on the sphere. A new strong converse inequality for given in this paper plays a significant role in the proof.