Worst-case optimal approximation with increasingly flat Gaussian kernels
From MaRDI portal
Publication:6320036
DOI10.1007/S10444-020-09767-1arXiv1906.02096MaRDI QIDQ6320036
Publication date: 5 June 2019
Abstract: We study worst-case optimal approximation of positive linear functionals in reproducing kernel Hilbert spaces induced by increasingly flat Gaussian kernels. This provides a new perspective and some generalisations to the problem of interpolation with increasingly flat radial basis functions. When the evaluation points are fixed and unisolvent, we show that the worst-case optimal method converges to a polynomial method. In an additional one-dimensional extension, we allow also the points to be selected optimally and show that in this case convergence is to the unique Gaussian quadrature type method that achieves the maximal polynomial degree of exactness. The proofs are based on an explicit characterisation of the reproducing kernel Hilbert space of the Gaussian kernel in terms of exponentially damped polynomials.
Numerical interpolation (65D05) Interpolation in approximation theory (41A05) Hilbert spaces with reproducing kernels (= (proper) functional Hilbert spaces, including de Branges-Rovnyak and other structured spaces) (46E22) Numerical quadrature and cubature formulas (65D32) Approximation by other special function classes (41A30) Numerical analysis (65-XX)
This page was built for publication: Worst-case optimal approximation with increasingly flat Gaussian kernels
