Extending the range of error estimates for radial approximation in Euclidean space and on spheres
Provides refined error bounds for radial basis function interpolation, benefiting approximation theory researchers working on scattered data interpolation.
The paper extends Schaback's error doubling trick to provide error estimates for radial interpolation of functions with intermediate smoothness, covering both Euclidean spaces and spheres, and also proves convergence of pseudoderivatives of the interpolation error.
We adapt Schaback's error doubling trick [R. Schaback. Improved error bounds for scattered data interpolation by radial basis functions. Math. Comp., 68(225):201--216, 1999.] to give error estimates for radial interpolation of functions with smoothness lying (in some sense) between that of the usual native space and the subspace with double the smoothness. We do this for both bounded subsets of R^d and spheres. As a step on the way to our ultimate goal we also show convergence of pseudoderivatives of the interpolation error.