# On the approximation of electromagnetic fields by edge finite elements. Part 3: sensitivity to coefficients

1 POEMS - Propagation des Ondes : Étude Mathématique et Simulation
Inria Saclay - Ile de France, UMA - Unité de Mathématiques Appliquées, CNRS - Centre National de la Recherche Scientifique : UMR7231
Abstract : In bounded domains, the regularity of the solutions to boundary value problems depends on the gometry, and on the coefficients that enter into the definition of the model. This is in particular the case for the time-harmonic Maxwell equations, whose solutions are the electromagnetic fields. In this paper, emphasis is put on the electric field. We study the regularity in terms of the fractional order Sobolev spaces $H^s$, $s\in[0,1]$. Precisely, our first goal is to determine the regularity of the electric field and of its curl, that is to find some regularity exponent $\tau\in(0,1)$, such that they both belong to $H^s$, for all $s\in[0,\tau)$. After that, one can derive error estimates. Here, the error is defined as the difference between the exact field and its approximation, where the latter is built with N\'ed\'elec's first family of finite elements. In addition to the regularity exponent, one needs to derive a stability constant that relates the norm of the error to the norm of the data: this is our second goal. We provide explicit expressions for both the regularity exponent and the stability constant with respect to the coefficients. We also discuss the accuracy of these expressions, and we provide some numerical illustrations.
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Journal articles

Cited literature [40 references]

https://hal.inria.fr/hal-02276430
Contributor : Patrick Ciarlet <>
Submitted on : Wednesday, June 17, 2020 - 9:34:43 AM
Last modification on : Friday, January 15, 2021 - 3:31:01 AM

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• HAL Id : hal-02276430, version 3

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Patrick Ciarlet. On the approximation of electromagnetic fields by edge finite elements. Part 3: sensitivity to coefficients. SIAM Journal on Mathematical Analysis, Society for Industrial and Applied Mathematics, In press. ⟨hal-02276430v3⟩

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