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Main Authors: Pradovera, Davide, Hiptmair, Ralf, Perugia, Ilaria
Format: Preprint
Published: 2025
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Online Access:https://arxiv.org/abs/2503.10194
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author Pradovera, Davide
Hiptmair, Ralf
Perugia, Ilaria
author_facet Pradovera, Davide
Hiptmair, Ralf
Perugia, Ilaria
contents This paper describes novel algorithms for the identification of (almost-)resonant behavior in scattering problems. Our methods, relying on rational approximation, aim at building surrogate models of what we call "field amplification", defined as the norm of the solution operator of the scattering problem, which we express through boundary-integral equations. To provide our techniques with theoretical foundations, we first derive results linking the field amplification to the spectral properties of the operator that defines the scattering problem. Such results are then used to justify the use of rational approximation in the surrogate-modeling task. Some of our proposed methods apply rational approximation in a "standard" way, building a rational approximant for either the solution operator directly or, in the interest of computational efficiency, for a randomly "sketched" version of it. Our other "hybrid" approaches are more innovative, combining rational-approximation-assisted root-finding with approximation using radial basis functions. Three key features of our methods are that (i) they are agnostic of the strategy used to discretize the scattering problem, (ii) they do not require any computations involving non-real wavenumbers, and (iii) they can adjust to different settings through the use of adaptive sampling strategies. We carry out some numerical experiments involving 2D scatterers to compare our approaches. In our tests, two of our approaches (one standard, one hybrid) emerge as the best performers, with one or the other being preferable, depending on whether emphasis is placed on accuracy or efficiency.
format Preprint
id arxiv_https___arxiv_org_abs_2503_10194
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Surrogate modeling of resonant behavior in scattering problems through adaptive rational approximation and sketching
Pradovera, Davide
Hiptmair, Ralf
Perugia, Ilaria
Numerical Analysis
Mathematical Physics
35B34, 35J05, 41A20, 65N38
This paper describes novel algorithms for the identification of (almost-)resonant behavior in scattering problems. Our methods, relying on rational approximation, aim at building surrogate models of what we call "field amplification", defined as the norm of the solution operator of the scattering problem, which we express through boundary-integral equations. To provide our techniques with theoretical foundations, we first derive results linking the field amplification to the spectral properties of the operator that defines the scattering problem. Such results are then used to justify the use of rational approximation in the surrogate-modeling task. Some of our proposed methods apply rational approximation in a "standard" way, building a rational approximant for either the solution operator directly or, in the interest of computational efficiency, for a randomly "sketched" version of it. Our other "hybrid" approaches are more innovative, combining rational-approximation-assisted root-finding with approximation using radial basis functions. Three key features of our methods are that (i) they are agnostic of the strategy used to discretize the scattering problem, (ii) they do not require any computations involving non-real wavenumbers, and (iii) they can adjust to different settings through the use of adaptive sampling strategies. We carry out some numerical experiments involving 2D scatterers to compare our approaches. In our tests, two of our approaches (one standard, one hybrid) emerge as the best performers, with one or the other being preferable, depending on whether emphasis is placed on accuracy or efficiency.
title Surrogate modeling of resonant behavior in scattering problems through adaptive rational approximation and sketching
topic Numerical Analysis
Mathematical Physics
35B34, 35J05, 41A20, 65N38
url https://arxiv.org/abs/2503.10194