Institut Élie Cartan de Lorraine

About: Institut Élie Cartan de Lorraine is a facility organization based out in Vandœuvre-lès-Nancy, France. It is known for research contribution in the topics: Boundary value problem & Stochastic differential equation. The organization has 345 authors who have published 1084 publications receiving 15512 citations. The organization is also known as: Institut Élie-Cartan de Nancy.

Moduli spaces of sheaves that are semistable with respect to a Kähler polarisation

Abstract: Using an existence criterion for good moduli spaces of Artin stacks by Alper– Fedorchuk–Smyth we construct a proper moduli space of rank two sheaves with fixed Chern classes on a given complex projective manifold that are Gieseker-Maruyama-semistable with respect to a fixed Kahler class.

Hydromorpho: A coupled model for unsteady Stokes/Exner equations and numerical results with Feel++ library

Abstract: We propose to couple the Exner equation with the Stokes equations to model the bedload sediment in geophysical flows . This work is a preliminary study to directly model the hydrodynamic flow by the unsteady Stokes equation instead of the classical shallow water equation. We focus in this proceeding on the coupling applying fluid structure interaction approach to morphodynamical behavior. In other words, we follow the approach of fluid interaction models replacing the structure equation by the Exner equation. The aim of this work is to validate the proposed procedure. These equations are solved by finite element method using the library FEEL++.

Explicit Computation of Robin Parameters in Optimized Schwarz Waveform Relaxation Methods for Schro¨dinger Equations Based on Pseudodifferential Operators

Abstract: The Optimized Schwarz Waveform Relaxation algorithm, a domain decomposition method based on Robin transmission condition, is becoming a popular computational method for solving evolution partial differential equations in parallel. Along with well-posedness, it offers a good balance between convergence rate, computational complexity and simplicity of the implementation. The fundamental question is the selection of the Robin parameter to optimize the convergence of the algorithm. In this paper, we propose an approach to explicitly estimate the Robin parameter which is based on the approximation of the transmission operators at the subdomain interfaces, for the linear/nonlinear SchrodingerSchr¨Schrodinger equation. Some illustrating numerical experiments are proposed for the one-and two-dimensional problems.

A coupling between integral equations and on-surface radiation conditions for diffraction problems by non convex scatterers

Abstract: The aim of this paper is to introduce an orignal coupling procedure between surface integral equation formulations and on-surface radiation condition (OSRC) methods for solving two-dimensional scattering problems for non convex structures. The key point is that the use of the OSRC introduces a sparse block in the surface operator representation of the wave field while the integral part leads to an improved accuracy of the OSRC method in the non convex part of the scattering structure. The procedure is given for both the Dirichlet and Neumann scattering problems. Some numerical simulations show the improvement induced by the coupling method.

K-théorie équivariante et groupoïdes

Abstract: Cette these porte principalement sur l’etude des groupoides etales. On etudie dans un premier temps l’action propre d’un groupe discret sur un espace localement compact et separe, qui fournit un exemple de groupoide etale (propre), puis de voir sous quelle condition le groupe de K-theorie equivariante peut etre decrit a l’aide de K-cocyles de fibres vectoriels complexes G-equivariant et dimension finie. Dans une deuxieme partie, on donne la definition de la moyennabilite a l’infi pour un groupoide etale localement compact, sigma-compact et separe. On etudie dans certains cas la relation entre l’exactitude de la C*-*algebres reduites du groupoide et la moyennabilite a l’infini du groupoide. Dans une derniere partie, en s’inspirant d’un article de Hilsum et Skandalis, on construit pour toute immersion K-orientee entre groupoides etales, un morphisme entre les groupes de K-theorie des C*-algebres reduites de ces groupoides etales et on etudie la fonctorialite d’une telle construction. Cette derniere partie contient aussi la demonstration d’une conjecture annoncee en 1987 par Hilsum et Skandalis