Discontinuous Moreau’s sweeping process and stability of the prox-regularity : Applications to nonconvex optimization and generalized equations

Cette thèse est consacrée, d'une part, à l'étude d'existence de solutions pour des problèmes d'évolution et, d'autre part, à la stabilité de la propriété de prox-régularité ensembliste. Nous étudions dans la première partie des processus de rafle de Moreau perturbés et discontinu du premier et du second ordre. L'ensemble mouvant est prox-régulier dans un espace de Hilbert réel quelconque et sa variation est contrôlé par une mesure de Radon. Des applications à la théorie de la complémentarité et à celle des inéquations variationnelles sont présentées. Dans la seconde partie, on donne des conditions suffisantes assurant la prox-régularité d'ensembles décrit par des contraintes non nécessairement lisses sous forme d'inégalités et/ ou d'égalités et plus généralement d'ensembles de solutions d'équations généralisées. On y développe également des conditions vérifiables assurant la préservation de la prox-régularité vis-à-vis d'opérations ensemblistes : les cas de l'intersection, d'image directe, de pré-image, d'union et projection sur un sous-espace sont considérés.In this dissertation, we study, on the one hand, the existence of solutions for some evolution problems and, on the other hand, the stability of prox-regularity under set operations. The first topic is devoted to first and second order nonconvex perturberd Moreau's sweeping processes in infinite dimensional framework. The moving set is assumed to be prox-regular and moved in a bounded variation way. Applications to the theory of complementarity problems and evolution variational inequalities are given. In the other topic, we first give verifiable sufficient conditions ensuring the prox-regularity of constrained sets and more generally for solution sets of generalized equations. We also develop the preservation of prox-regularity under set operations as intersection, direct image, inverse image, union and projection along a vector space

Truncated nonconvex state-dependent sweeping process: implicit and semi-implicit adapted Moreau’s catching-up algorithms

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An Existence Result for Discontinuous Second-Order Nonconvex State-Dependent Sweeping Processes

International audienceIn this paper, we study the existence of solutions for a time and state-dependent discontinuous nonconvex second order sweeping process with a multivalued perturbation. The moving set is assumed to be prox-regular, relatively ball-compact with a bounded variation. The perturbation of the normal cone is a scalarly upper semicontinuous convex valued multimapping satisfying a linear growth condition possibly time-dependent. As an application of the theoretical results, we investigate the theory of evolution quasi-variational inequalities

Discontinuous sweeping process with prox-regular sets

International audienceIn this paper, we study the well−posedness (in the sense of existence and uniqueness of a solution) of a discontinuous sweeping process involving prox-regular sets in Hilbert spaces. The variation of the moving set is controlled by a positive Radon measure and the perturbation is assumed to satisfy a Lipschitz property. The existence of a solution with bounded variation is achieved thanks to the Moreau’s catching-up algorithm adapted to this kind of problem. Various properties and estimates of jumps of the solution are also provided. We give sufficient conditions to ensure the uniform prox-regularity when the moving set is described by inequality constraints. As an application, we consider a nonlinear differential complementarity system which is a combination of an ordinary differential equation with a nonlinear complementarily condition. Such problems appear in many areas such as nonsmooth mechanics, nonregular electrical circuits and control systems

Prox-regularity approach to generalized equations and image projection

In this paper, we first investigate the prox-regularity behaviour of solution mappings to generalized equations. This study is realized through a nonconvex uniform Robinson−Ursescu type theorem. Then, we derive new significant results for the preservation of prox-regularity under various and usual set operations. The role and applications of prox-regularity of solution sets of generalized equations are illustrated with dynamical systems with constraints

Preservation of Prox-Regularity of Sets with Applications to Constrained Optimization

International audienceIn this paper, we first provide counterexamples showing that sublevels of prox-regular functions and levels of differentiable mappings with Lipschitz derivatives may fail to be prox-regular. Then, we prove the uniform prox-regularity of such sets under usual verifiable qualification conditions. The preservation of uniform prox-regularity of intersection and inverse image under usual qualification conditions is also established. Applications to constrained optimization problems are given

Prox-regular sets and Legendre-Fenchel transform related to separation properties

This paper is devoted to nonconvex/prox-regular separations of sets in Hilbert spaces. We introduce the Legendre-Fenchel r-conjugate of a prescribed function and r-quadratic support functionals and points of a given set, all associated to a positive constant r. By means of these concepts we obtain nonlinear functional separations for points and prox-regular sets. In addition to such functional separations, we also establish geometric separation results with balls for a prox-regular set and a strongly convex set

Metric subregularity and ω(•)-normal regularity properties

In this paper, we establish through an openness condition the metric subregularity of a multimapping with normal ω(•)-regularity of either the graph or values. Various preservation results for prox-regular and subsmooth sets are also provided

Maximization of the Steklov Eigenvalues with a Diameter Constraint

International audienceIn this paper, we address the problem of maximizing the Steklov eigenvalues with a diameter constraint. We provide an estimate of the Steklov eigenvalues for a convex domain in terms of its diameter and volume and we show the existence of an optimal convex domain. We establish that balls are never maximizers, even for the first non-trivial eigenvalue that contrasts with the case of volume or perimeter constraints. Under an additional regularity assumption, we are able to prove that the Steklov eigenvalue is multiple for the optimal domain. We illustrate our theoretical results by giving some optimal domains in the plane thanks to a numerical algorithm