Polynomial-free unisolvence of polyharmonic splines with odd exponent by random sampling

Abstract

In a recent paper almost sure unisolvence of RBF interpolation at random points with no polynomial addition was proved, for Thin-Plate Splines and Radial Powers with noninteger exponent. The proving technique left unsolved the case of odd exponents. In this short note we prove almost sure polynomial-free unisolvence in such instances, by a deeper analysis of the interpolation matrix determinant and fundamental properties of analytic functions.

Keywords: multivariate interpolation, Radial Basis Functions, polyharmonic splines, odd integer exponent, unisolvence, analytic functions