Patrick Ciarlet

On traces for functional spaces related to Maxwell's equations Part I: An integration by parts formula in Lipschitz polyhedra

The aim of this paper is to study the tangential trace and tangential components of fields which belong to the space H(curl, Omega), when Omega is a polyhedron with Lipschitz continuous boundary. The appropriate functional setting is developed in order to suitably define these traces on the whole boundary and on a part of it (for partially vanishing fields and general ones.) In both cases it is possible to define ad hoc dualities among tangential trace and tangential components. In addition, the validity of two related integration by parts formulae is provided. Copyright (C) 2001 John Wiley & Sons, Ltd.

On traces for functional spaces related to Maxwell's equations Part II: Hodge decompositions on the boundary of Lipschitz polyhedra and applications

Hodge decompositions of tangential vector fields defined on piecewise regular manifolds are provided. The first step is the study of L2 tangential fields and then the attention is focused on some particular Sobolev spaces of order

Numerical solution to the time-dependent Maxwell equations in axisymmetric singular domains: the singular complement method

-{1\over 2}

Convergence and superconvergence of staggered discontinuous Galerkin methods for the three-dimensional Maxwell's equations on Cartesian grids

\nopagenumbers\end. In order to reach this goal, it is required to properly define the first order differential operators and to investigate their properties. When the manifold Γ is the boundary of a polyhedron Ω, these spaces are important in the analysis of tangential trace mappings for vector fields in H(curl, Ω) on the whole boundary or on a part of it. By means of these Hodge decompositions, one can then provide a complete characterization of these trace mappings: general extension theorems, from the boundary, or from a part of it, to the inside; definition of suitable dualities and validity of integration by parts formulae. Copyright

On the Optimality of the Median Cut Spectral Bisection Graph Partitioning Method

In this paper, we present a method to solve numerically the axisymmetric time-dependent Maxwell equations in a singular domain. In [Math. Methods Appl. Sci. 25 (2002) 49; Math. Methods Appl. Sci. 26 (2003) 861], the mathematical tools and an in-depth study of the problems posed in the meridian half-plane were exposed. The numerical method and experiments based on this theory are now described here. It is also the generalization to axisymmetric problems of the Singular Complement Method that we developed to solve Maxwell equations in 2D singular domains (see [C. R. Acad. Sci. Paris, t. 330 (2000) 391]). It is based on a splitting of the space of solutions in a regular subspace, and a singular one, derived from the singular solutions of the Laplace problem. Numerical examples are finally given, to illustrate our purpose. In particular, they show how the Singular Complement Method captures the singular part of the solution.

A staggered discontinuous Galerkin method for wave propagation in media with dielectrics and meta-materials

In this paper, a new type of staggered discontinuous Galerkin methods for the three dimensional Maxwells equations is developed and analyzed. The spatial discretization is based on staggered Cartesian grids so that many good properties are obtained. First of all, our method has the advantages that the numerical solution preserves the electromagnetic energy and automatically fulfills a discrete version of the Gauss law. Moreover, the mass matrices are diagonal, thus time marching is explicit and is very efficient. Our method is high order accurate and the optimal order of convergence is rigorously proved. It is also very easy to implement due to its Cartesian structure and can be regarded as a generalization of the classical Yees scheme as well as the quadrilateral edge finite elements. Furthermore, a superconvergence result, that is the convergence rate is one order higher at interpolation nodes, is proved. Numerical results are shown to confirm our theoretical statements, and applications to problems in unbounded domains with the use of PML are presented. A comparison of our staggered method and non-staggered method is carried out and shows that our method has better accuracy and efficiency.

Solving electromagnetic eigenvalue problems in polyhedral domains with nodal finite elements

Recursive spectral bisection (RSB) is a heuristic technique for finding a minimum cut graph bisection. To use this method the second eigenvector of the Laplacian of the graph is computed and from it a bisection is obtained. The most common method is to use the median of the components of the second eigenvector to induce a bisection. We prove here that this median cut method is optimal in the sense that the partition vector induced by it is the closest partition vector, in any ls norm, for

Characterization of the singular part of the solution of Maxwell's equations in a polyhedral domain

s\ge1

T-coercivity and continuous Galerkin methods: application to transmission problems with sign changing coefficients

, to the second eigenvector. Moreover, we prove that the same result also holds for any m-partition, that is, a partition into m and (n-m)

Some Observations on Generalized Saddle-Point Problems

vertices, when using the mth largest or smallest components of the second eigenvector.