activity
20242026
collaborators

9 papers

math.NA2026

Optimal compression of kernel matrices by interpolets with application to high-dimensional approximation

Helmut Harbrecht, Lucio Antonio Rosi

We consider the compression of kernel matrices on the unit interval by interpolets that have sufficiently many vanishing moments. We define a compression rule which discard…

math.NA2026

Simulation of Gaussian random fields on surfaces using the isogeometric finite element method

Helmut Harbrecht, Florian Sonderegger, Remo von Rickenbach

We are concerned with the fast simulation of random fields on closed surfaces in which are generated by the (Whittle-) Matérn class of covariance functions. To this…

math.NA2025

Kernel interpolation in Sobolev spaces of hybrid regularity

M. Griebel, H. Harbrecht

Kernel interpolation in tensor product reproducing kernel Hilbert spaces allows for the use of sparse grids to mitigate the curse of the dimension. Typically, besides the generic c…

math.NA2025

Kernel interpolation on generalized sparse grids

Michael Griebel, Helmut Harbrecht, Michael Multerer

We consider scattered data approximation on product regions of equal and different dimensionality. On each of these regions, we assume quasi-uniform but unstructured data sites and…

math.NA2025

On the Compressibility of Integral Operators in Anisotropic Wavelet Coordinates

Helmut Harbrecht, Remo von Rickenbach

The present article is concerned with the s*-compressibility of classical boundary integral operators in anisotropic wavelet coordinates. Having the s*-compressibility at hand, one…

math.NA2025

Samplets: Wavelet concepts for scattered data

Helmut Harbrecht, Michael Multerer

This chapter is dedicated to recent developments in the field of wavelet analysis for scattered data. We introduce the concept of samplets, which are signed measures of wavelet typ…

math.FA2024

On Sobolev and Besov Spaces of Hybrid Regularity

Helmut Harbrecht, Remo von Rickenbach

The present article is concerned with the nonlinear approximation of functions in the Sobolev space H^q with respect to a tensor-product, or hyperbolic wavelet basis on the unit n-…

math.NA2024

On Quasi-Localized Dual Pairs in Reproducing Kernel Hilbert Spaces

Helmut Harbrecht, Rüdiger Kempf, Michael Multerer

In scattered data approximation, the span of a finite number of translates of a chosen radial basis function is used as approximation space and the basis of translates is used for…

math.NA2024

The dimension weighted fast multipole method for scattered data approximation

Helmut Harbrecht, Michael Multerer, Jacopo Quizi

The present article is concerned scattered data approximation for higher dimensional data sets which exhibit an anisotropic behavior in the different dimensions. Tailoring sparse p…