Efficient approximation of high-frequency Helmholtz solutions by Gaussian coherent states

Fuente: arXiv
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Main Authors: Chaumont-Frelet, T., Dolean, V., Ingremeau, M.
Format: Preprint
Published: 2022
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author Chaumont-Frelet, T.
Dolean, V.
Ingremeau, M.
author_facet Chaumont-Frelet, T.
Dolean, V.
Ingremeau, M.
contents We introduce new finite-dimensional spaces specifically designed to approximate the solutions to high-frequency Helmholtz problems with smooth variable coefficients in dimension $d$. These discretization spaces are spanned by Gaussian coherent states, that have the key property to be localised in phase space. We carefully select the Gaussian coherent states spanning the approximation space by exploiting the (known) micro-localisation properties of the solution. For a large class of source terms (including plane-wave scattering problems), this choice leads to discrete spaces that provide a uniform approximation error for all wavenumber $k$ with a number of degrees of freedom scaling as $k^{d-1/2}$, which we rigorously establish. In comparison, for discretization spaces based on (piecewise) polynomials, the number of degrees of freedom has to scale at least as $k^d$ to achieve the same property. These theoretical results are illustrated by one-dimensional numerical examples, where the proposed discretization spaces are coupled with a least-squares variational formulation.
format Preprint
id arxiv_https___arxiv_org_abs_2208_04851
institution arXiv
publishDate 2022
record_format arxiv
spellingShingle Efficient approximation of high-frequency Helmholtz solutions by Gaussian coherent states
Chaumont-Frelet, T.
Dolean, V.
Ingremeau, M.
Numerical Analysis
Analysis of PDEs
We introduce new finite-dimensional spaces specifically designed to approximate the solutions to high-frequency Helmholtz problems with smooth variable coefficients in dimension $d$. These discretization spaces are spanned by Gaussian coherent states, that have the key property to be localised in phase space. We carefully select the Gaussian coherent states spanning the approximation space by exploiting the (known) micro-localisation properties of the solution. For a large class of source terms (including plane-wave scattering problems), this choice leads to discrete spaces that provide a uniform approximation error for all wavenumber $k$ with a number of degrees of freedom scaling as $k^{d-1/2}$, which we rigorously establish. In comparison, for discretization spaces based on (piecewise) polynomials, the number of degrees of freedom has to scale at least as $k^d$ to achieve the same property. These theoretical results are illustrated by one-dimensional numerical examples, where the proposed discretization spaces are coupled with a least-squares variational formulation.
title Efficient approximation of high-frequency Helmholtz solutions by Gaussian coherent states
topic Numerical Analysis
Analysis of PDEs
url https://arxiv.org/abs/2208.04851