Stability of convergence rates: Kernel interpolation on non-Lipschitz domains

Fuente: arXiv
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Main Authors: Wenzel, Tizian, Santin, Gabriele, Haasdonk, Bernard
Format: Preprint
Published: 2022
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author Wenzel, Tizian
Santin, Gabriele
Haasdonk, Bernard
author_facet Wenzel, Tizian
Santin, Gabriele
Haasdonk, Bernard
contents Error estimates for kernel interpolation in Reproducing Kernel Hilbert Spaces (RKHS) usually assume quite restrictive properties on the shape of the domain, especially in the case of infinitely smooth kernels like the popular Gaussian kernel. In this paper we leverage an analysis of greedy kernel algorithms to prove that it is possible to obtain convergence results (in the number of interpolation points) for kernel interpolation for arbitrary domains $Ω\subset \mathbb{R}^d$, thus allowing for non-Lipschitz domains including e.g. cusps and irregular boundaries. Especially we show that, when going to a smaller domain $\tildeΩ \subset Ω\subset \mathbb{R}^d$, the convergence rate does not deteriorate - i.e. the convergence rates are stable with respect to going to a subset. The impact of this result is explained on the examples of kernels of finite as well as infinite smoothness like the Gaussian kernel. A comparison to approximation in Sobolev spaces is drawn, where the shape of the domain $Ω$ has an impact on the approximation properties. Numerical experiments illustrate and confirm the experiments.
format Preprint
id arxiv_https___arxiv_org_abs_2203_12532
institution arXiv
publishDate 2022
record_format arxiv
spellingShingle Stability of convergence rates: Kernel interpolation on non-Lipschitz domains
Wenzel, Tizian
Santin, Gabriele
Haasdonk, Bernard
Numerical Analysis
Error estimates for kernel interpolation in Reproducing Kernel Hilbert Spaces (RKHS) usually assume quite restrictive properties on the shape of the domain, especially in the case of infinitely smooth kernels like the popular Gaussian kernel. In this paper we leverage an analysis of greedy kernel algorithms to prove that it is possible to obtain convergence results (in the number of interpolation points) for kernel interpolation for arbitrary domains $Ω\subset \mathbb{R}^d$, thus allowing for non-Lipschitz domains including e.g. cusps and irregular boundaries. Especially we show that, when going to a smaller domain $\tildeΩ \subset Ω\subset \mathbb{R}^d$, the convergence rate does not deteriorate - i.e. the convergence rates are stable with respect to going to a subset. The impact of this result is explained on the examples of kernels of finite as well as infinite smoothness like the Gaussian kernel. A comparison to approximation in Sobolev spaces is drawn, where the shape of the domain $Ω$ has an impact on the approximation properties. Numerical experiments illustrate and confirm the experiments.
title Stability of convergence rates: Kernel interpolation on non-Lipschitz domains
topic Numerical Analysis
url https://arxiv.org/abs/2203.12532