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A finite element method for the solution of the time-dependent Maxwell equations in mixed form is presented. The method allows for local $hp$-refinement in space and in time. To this end, a space-time Galerkin approach is employed. In…

Numerical Analysis · Mathematics 2014-12-18 Martin Lilienthal , Sascha M. Schnepp , Thomas Weiland

In this paper, we present a fully discretized Calder\'{o}n Calculus for the two dimensional Helmholtz equation. This full discretization can be understood as highly non-conforming Petrov-Galerkin methods, based on two staggered grids of…

Numerical Analysis · Mathematics 2012-10-30 Victor Dominguez , Sijiang L. Lu , Francisco-Javier Sayas

A waveguide coincides with a three-dimensional domain G having finitely many cylindrical outlets to infinity; the boundary of G is smooth. In G, we consider the stationary Maxwell system with real spectral parameter k and identity matrices…

Mathematical Physics · Physics 2012-06-04 B. A. Plamenevskii , A. S. Poretckii

Collocation boundary element methods for integral equations are easier to implement than Galerkin methods because the elements of the discretization matrix are given by lower-dimensional integrals. For that same reason, the matrix assembly…

Numerical Analysis · Mathematics 2021-04-01 Georg Maierhofer , Daan Huybrechs

A low frequency approximation of the discrete Sommerfeld diffraction problems, involving the scattering of a time harmonic lattice wave incident on square lattice by a discrete Dirichlet or a discrete Neumann half-plane, is investigated. It…

Analysis of PDEs · Mathematics 2019-08-08 Basant Lal Sharma

We propose a high-order discontinuous Galerkin scheme for nonlinear acoustic waves on polytopic meshes. To model sound propagation with and without losses, we use Westervelt's nonlinear wave equation with and without strong damping.…

Numerical Analysis · Mathematics 2020-05-20 Paola. F. Antonietti , Ilario Mazzieri , Markus Muhr , Vanja Nikolić , Barbara Wohlmuth

This paper is concerned with a Galerkin boundary element method solving the two dimensional exterior elastic wave scattering problem. The original problem is first reduced to the so-called Burton-Miller (\cite{BM71}) boundary integral…

Numerical Analysis · Mathematics 2017-08-15 Gang Bao , Liwei Xu , Tao Yin

We present a new algorithm for the discretization of the Vlasov-Maxwell system of equations for the study of plasmas in the kinetic regime. Using the discontinuous Galerkin finite element method for the spatial discretization, we obtain a…

Plasma Physics · Physics 2017-11-22 J. Juno , A. Hakim , J. TenBarge , E. Shi , W. Dorland

Two local discontinuous Galerkin (LDG) methods using some non-standard numerical fluxes are developed for the Helmholtz equation with the first order absorbing boundary condition in the high frequency regime. It is shown that the proposed…

Numerical Analysis · Mathematics 2010-10-25 Xiaobing Feng , Yulong Xing

We consider the numerical approximation of linear damped wave systems by Galerkin approximations in space and appropriate time-stepping schemes. Based on a dissipation estimate for a modified energy, we prove exponential decay of the…

Numerical Analysis · Mathematics 2015-11-30 Herbert Egger , Thomas Kugler

We consider a simple initial-boundary-value problem for the shallow water equations in one space dimension. We discretize the problem in space by the standard Galerkin finite element method on a quasiuniform mesh and in time by the…

Numerical Analysis · Mathematics 2018-10-26 D. c. Antonopoulos , V. a. Dougalis , G. Kounadis

Wave propagation and acoustic scattering problems require vast computational resources to be solved accurately at high frequencies. Asymptotic methods can make this cost potentially frequency independent by explicitly extracting the…

Numerical Analysis · Mathematics 2018-01-16 Daan Huybrechs , Peter Opsomer

We consider nodal-based Lagrangian interpolations for the finite element approximation of the Maxwell eigenvalue problem. The first approach introduced is a standard Galerkin method on Powell-Sabin meshes, which has recently been shown to…

Numerical Analysis · Mathematics 2023-04-04 Daniele Boffi , Ramon Codina , Önder Türk

We show how a Trefftz Discontinuous Galerkin (TDG) method for the displacement form of the Helmholtz equation can be used to approximate problems having a generalized impedance boundary condition (GIBC) involving surface derivatives of the…

Numerical Analysis · Mathematics 2018-05-17 Shelvean Kapita , Peter Monk , Virginia Selgas

Fast and accurate resolution of electromagnetic problems via the \ac{BEM} is oftentimes challenged by conditioning issues occurring in three distinct regimes: (i) when the frequency decreases and the discretization density remains constant,…

Computational Physics · Physics 2020-04-22 Alexandre Dély , Adrien Merlini , Simon B. Adrian , Francesco P. Andriulli

We propose a high order unfitted finite element method for solving timeharmonic Maxwell interface problems. The unfitted finite element method is based on a mixed formulation in the discontinuous Galerkin framework on a Cartesian mesh with…

Numerical Analysis · Mathematics 2024-10-25 Zhiming Chen , Ke Li , Maohui Lyu , Xueshuang Xiang

The numerical solution of time-dependent radiative transfer problems is challenging, both, due to the high dimension as well as the anisotropic structure of the underlying integro-partial differential equation. In this paper we propose a…

Numerical Analysis · Mathematics 2015-12-04 Herbert Egger , Matthias Schlottbom

In the present paper we consider linear and isotropic Maxwell equations with inhomogeneous interface conditions. We discretize the problem with the discontinuous Galerkin method in space and with the leapfrog scheme in time. An analytical…

Numerical Analysis · Mathematics 2025-10-06 Benjamin Dörich , Julian Dörner , Marlis Hochbruck

Semi-discrete Galerkin formulations of transient wave equations, either with conforming or discontinuous Galerkin finite element discretizations, typically lead to large systems of ordinary differential equations. When explicit time…

Numerical Analysis · Mathematics 2012-10-19 Marcus Grote , Teodora Mitkova

Cross-diffusion systems are systems of nonlinear parabolic partial differential equations that are used to describe dynamical processes in several application, including chemical concentrations and cell biology. We present a space-time…

Analysis of PDEs · Mathematics 2022-05-19 Marcel Braukhoff , Ilaria Perugia , Paul Stocker