A quasilinear transmission problem with application to Maxwell equations with a divergence-free $\mathcal D$-field

Fuente: arXiv
Gespeichert in:
Bibliographische Detailangaben
Hauptverfasser: Dohnal, Tomáš, Romani, Giulio, Tietz, Daniel P.
Format: Preprint
Veröffentlicht: 2021
Schlagworte:
Online-Zugang:
Tags: Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
_version_ 1866918101933621248
author Dohnal, Tomáš
Romani, Giulio
Tietz, Daniel P.
author_facet Dohnal, Tomáš
Romani, Giulio
Tietz, Daniel P.
contents Maxwell equations in the absence of free charges require initial data with a divergence free displacement field $\mathcal D$. In materials in which the dependence $\mathcal D=\mathcal D(\mathcal E)$ is nonlinear the quasilinear problem $\nabla\cdot\mathcal D(\mathcal E)=0$ is hence to be solved. In many applications, e.g. in the modelling of wave-packets, an approximative asymptotic ansatz of the electric field $\mathcal E$ is used, which satisfies this divergence condition at $t=0$ only up to a small residual. We search then for a small correction of the ansatz to enforce $\nabla\cdot\mathcal D(\mathcal E)=0$ at $t=0$ and choose this correction in the form of a gradient field. In the usual case of a power type nonlinearity in $\mathcal D(\mathcal E)$ this leads to the sum of the Laplace and $p$-Laplace operators. We also allow for the medium to consist of two different materials so that a transmission problem across an interface is produced. We prove the existence of the correction term for a general class of nonlinearities and provide regularity estimates for its derivatives, independent of the $L^2$-norm of the original ansatz. In this way, when applied to the wave-packet setting, the correction term is indeed asymptotically smaller than the original ansatz. We also provide numerical experiments to support our analysis.
format Preprint
id arxiv_https___arxiv_org_abs_2109_08513
institution arXiv
publishDate 2021
record_format arxiv
spellingShingle A quasilinear transmission problem with application to Maxwell equations with a divergence-free $\mathcal D$-field
Dohnal, Tomáš
Romani, Giulio
Tietz, Daniel P.
Analysis of PDEs
35J62 35R05 35B65 35B45 35Q61 78M45
Maxwell equations in the absence of free charges require initial data with a divergence free displacement field $\mathcal D$. In materials in which the dependence $\mathcal D=\mathcal D(\mathcal E)$ is nonlinear the quasilinear problem $\nabla\cdot\mathcal D(\mathcal E)=0$ is hence to be solved. In many applications, e.g. in the modelling of wave-packets, an approximative asymptotic ansatz of the electric field $\mathcal E$ is used, which satisfies this divergence condition at $t=0$ only up to a small residual. We search then for a small correction of the ansatz to enforce $\nabla\cdot\mathcal D(\mathcal E)=0$ at $t=0$ and choose this correction in the form of a gradient field. In the usual case of a power type nonlinearity in $\mathcal D(\mathcal E)$ this leads to the sum of the Laplace and $p$-Laplace operators. We also allow for the medium to consist of two different materials so that a transmission problem across an interface is produced. We prove the existence of the correction term for a general class of nonlinearities and provide regularity estimates for its derivatives, independent of the $L^2$-norm of the original ansatz. In this way, when applied to the wave-packet setting, the correction term is indeed asymptotically smaller than the original ansatz. We also provide numerical experiments to support our analysis.
title A quasilinear transmission problem with application to Maxwell equations with a divergence-free $\mathcal D$-field
topic Analysis of PDEs
35J62 35R05 35B65 35B45 35Q61 78M45
url https://arxiv.org/abs/2109.08513