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Hauptverfasser: Arnold, Anton, Klein, Christian, Körner, Jannis, Melenk, Jens Markus
Format: Preprint
Veröffentlicht: 2024
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Online-Zugang:https://arxiv.org/abs/2401.10141
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author Arnold, Anton
Klein, Christian
Körner, Jannis
Melenk, Jens Markus
author_facet Arnold, Anton
Klein, Christian
Körner, Jannis
Melenk, Jens Markus
contents This paper is dedicated to the efficient numerical computation of solutions to the 1D stationary Schrödinger equation in the highly oscillatory regime. We compute an approximate solution based on the well-known WKB-ansatz, which relies on an asymptotic expansion w.r.t. the small parameter $\varepsilon$. Assuming that the coefficient in the equation is analytic, we derive an explicit error estimate for the truncated WKB series, in terms of $\varepsilon$ and the truncation order $N$. For any fixed $\varepsilon$, this allows to determine the optimal truncation order $N_{opt}$ which turns out to be proportional to $\varepsilon^{-1}$. When chosen this way, the resulting error of the optimally truncated WKB series behaves like $\mathcal{O}(\exp(-r/\varepsilon))$, with some parameter $r>0$. The theoretical results established in this paper are confirmed by several numerical examples.
format Preprint
id arxiv_https___arxiv_org_abs_2401_10141
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Optimally truncated WKB approximation for the 1D stationary Schrödinger equation in the highly oscillatory regime
Arnold, Anton
Klein, Christian
Körner, Jannis
Melenk, Jens Markus
Numerical Analysis
34E20, 81Q20, 65L11, 65M70
This paper is dedicated to the efficient numerical computation of solutions to the 1D stationary Schrödinger equation in the highly oscillatory regime. We compute an approximate solution based on the well-known WKB-ansatz, which relies on an asymptotic expansion w.r.t. the small parameter $\varepsilon$. Assuming that the coefficient in the equation is analytic, we derive an explicit error estimate for the truncated WKB series, in terms of $\varepsilon$ and the truncation order $N$. For any fixed $\varepsilon$, this allows to determine the optimal truncation order $N_{opt}$ which turns out to be proportional to $\varepsilon^{-1}$. When chosen this way, the resulting error of the optimally truncated WKB series behaves like $\mathcal{O}(\exp(-r/\varepsilon))$, with some parameter $r>0$. The theoretical results established in this paper are confirmed by several numerical examples.
title Optimally truncated WKB approximation for the 1D stationary Schrödinger equation in the highly oscillatory regime
topic Numerical Analysis
34E20, 81Q20, 65L11, 65M70
url https://arxiv.org/abs/2401.10141