activity
20132023
most citedSpectrum of a diffusion operator with coefficient changing sign over a small inclusion

7 citations · 23 across the 17 of their papers we have counts for

collaborators

19 papers

math.NA2023★ 1 cited

Boundary Element Methods for the Laplace Hypersingular Integral Equation on Multiscreens: a two-level Substructuring Preconditioner

Martin Averseng, Xavier Claeys, Ralf Hiptmair

We present a preconditioning method for the linear systems arising from the boundary element discretization of the Laplace hypersingular equation on a -dimensional triangulated…

math.NA2023★ 1 cited

Multi-domain FEM-BEM coupling for acoustic scattering

Marcella Bonazzoli, Xavier Claeys

We model time-harmonic acoustic scattering by an object composed of piece-wise homogeneous parts and an arbitrarily heterogeneous part. We propose and analyze new formulations that…

math.AP2023

Non-local optimized Schwarz method with physical boundaries

Xavier Claeys

We extend the theoretical framework of non-local optimized Schwarz methods as introduced in [Claeys,2021], considering an Helmholtz equation posed in a bounded cavity supplemented…

math.NA2022

Fractured Meshes

Martin Averseng, Xavier Claeys, Ralf Hiptmair

This work introduces ``generalized meshes", a type of meshes suited for the discretization of partial differential equations in non-regular geometries. Generalized meshes extend re…

math.NA2022★ 1 cited

How does the partition of unity influence SORAS preconditioner?

Marcella Bonazzoli, Xavier Claeys, Frédéric Nataf +1

We investigate the influence of the choice of the partition of unity on the convergence of the Symmetrized Optimized Restricted Additive Schwarz (SORAS) preconditioner for the reac…

math.NA2022

A new perspective on the fictitious space lemma

Xavier Claeys

In the present contribution we propose a new proof of the so-called fictitious space lemma. For the proof, we exhibit an explicit expression for the inverse of additive Schwarz pre…

math.NA2022

A Directional Equispaced interpolation-based Fast Multipole Method for oscillatory kernels

Igor Chollet, Xavier Claeys, Pierre Fortin +1

Fast Multipole Methods (FMMs) based on the oscillatory Helmholtz kernel can reduce the cost of solving N-body problems arising from Boundary Integral Equations (BIEs) in acoustic o…

math.NA2021★ 1 cited

Nonlocal Optimized Schwarz Methods for time-harmonic electromagnetics

Xavier Claeys, Francis Collino, Emile Parolin

We introduce a new domain decomposition strategy for time harmonic Maxwell's equations that is valid in the case of automatically generated subdomain partitions with possible prese…

math.NA2021

Non-self adjoint impedance in Generalized Optimized Schwarz Methods

Xavier Claeys

We present a convergence theory for Optimized Schwarz Methods that rely on a non-local exchange operator and covers the case of coercive possibly non-self-adjoint impedance operato…

math.NA2021

Continuity estimates for Riesz potentials on polygonal boundaries

Xavier Claeys, Muhammad Hassan, Benjamin Stamm

Riesz potentials are well known objects of study in the theory of singular integrals that have been the subject of recent, increased interest from the numerical analysis community…

math.NA2020★ 1 cited

Analysis of the SORAS domain decomposition preconditioner for non-self-adjoint or indefinite problems

Marcella Bonazzoli, Xavier Claeys, Frédéric Nataf +1

We analyze the convergence of the one-level overlapping domain decomposition preconditioner SORAS (Symmetrized Optimized Restricted Additive Schwarz) applied to a generic linear sy…

math.NA2020

Local Multiple Traces Formulation for Electromagnetics: Stability and Preconditioning for Smooth Geometries

Alan Ayala, Xavier Claeys, Paul Escapil-Inchauspé +1

We consider the time-harmonic electromagnetic transmission problem for the unit sphere. Appealing to a vector spherical harmonics analysis, we prove the first stability result of t…

math.NA2020★ 2 cited

Robust treatment of cross points in Optimized Schwarz Methods

Xavier Claeys, Emile Parolin

In the field of Domain Decomposition (DD), Optimized Schwarz Method (OSM) appears to be one of the prominent techniques to solve large scale time-harmonic wave propagation problems…

math.AP2019★ 2 cited

A new variant of the Optimised Schwarz Method for arbitrary non-overlapping subdomain partitions

Xavier Claeys

We consider a scalar wave propagation in harmonic regime modelled by Helmholtz equation with heterogeneous coefficients. Using the Multi-Trace Formalism (MTF), we propose a new var…

math.AP2015★ 6 cited

Oscillating behaviour of the spectrum for a plasmonic problem in a domain with a rounded corner

Lucas Chesnel, Xavier Claeys, Sergei A. Nazarov

We investigate the eigenvalue problem in a 2D domain divided into two regions . We are interested in situations where …

math.AP2015

Essential spectrum of local multi-trace boundary integral operators

Xavier Claeys

Considering pure transmission scattering problems in piecewise constant media, we derive an exact analytic formula for the spectrum of the corresponding local multi-trace boundary…

math.NA2014★ 1 cited

A numerical approach for the Poisson equation in a planar domain with a small inclusion

Lucas Chesnel, Xavier Claeys

We consider the Poisson equation in a domain with a small hole of size . We present a simple numerical method, based on an asymptotic analysis, which allows to approximate robus…

math.AP2014★ 7 cited

Spectrum of a diffusion operator with coefficient changing sign over a small inclusion

Lucas Chesnel, Xavier Claeys, Sergei A. Nazarov

We study a spectral problem for a diffusion like equation in a 3D domain . The main originality lies in the presence of a parameter , whose sign changes o…

math.AP2013

A curious instability phenomenon for a rounded corner in presence of a negative material

Lucas Chesnel, Xavier Claeys, Sergey A. Nazarov

We study a 2D scalar harmonic wave transmission problem between a classical dielectric and a medium with a real-valued negative permittivity/permeability which models a metal at op…