12 mai 2018 @ 14:00 – 15:00 – La théorie des algèbres d’opérateurs fut fondée en 1930 par John von Neumann qui cherchait à formaliser mathématiquement la toute jeune théorie de la mécanique quantique. L’idée est de remplacer l’algèbre commutative des observables décrivant un système classique, par une algèbre d’opérateurs sur un espace de Hilbert qui n’est plus nécessairement commutative. Pour le physicien, […]
11 mai 2018 @ 10:30 – 11:30 –
9 mai 2018 @ 10:00 – 12:00 –
19 avril 2018 @ 15:45 – 16:45 – Résumé
19 avril 2018 @ 14:15 – 15:15 – I will explain how equations of Classical Mechanics, defined from Poisson structures, can emerge from Quantum Mechanics. This is done via self-consistency equations, which in turn imply an extended quantum dynamics. This situation generically appears for quantum systems with long-range interactions, as in the so-called BCS theory of (conventional) superconductivity.
19 avril 2018 @ 10:45 – 11:45 – In these two presentations, we will first introduce using basic stochastic calculus, the parametrx method and then show how to deduce an unbiased simulation method and its interpretations. We will discuss its advantages and shortcomings and then discuss how to solve them. using a second order method. We will also give some simulation results and […]
18 avril 2018 @ 11:00 – 12:15 – We consider a critically branching population in R^d of particles of K types, starting off from a Poisson random population. The branching laws, lifetimes and motions of particles are type-dependent. We give conditions for asymptotic extinction in the following two cases: 1. All particle lifetimes have finite means, 2. There is a particle whose lifetime […]
17 avril 2018 @ 14:00 – 15:00 – The objective of this work is the mathematical study for a Bresse system, consisting of coupled three wave equations in one dimensional open bounded domain. This system has its origin in the mechanics of structures and especially in the balance of elastic bars. We are interested in Bresse systems with three memories and three delays. […]
17 avril 2018 @ 10:45 – 11:45 – The time-harmonic formulation of Maxwell’s equations presents several difficulties when the frequency is large. Here we propose a precise and efficient solution strategy that couples high order finite element discretizations with domain decomposition preconditioners. Finite elements suited for the approximation of the electric field are the curl-conforming (or edge) finite elements. Here, we revisit the […]
13 avril 2018 @ 11:00 – 12:00 – The localization of a critical point of minimum type of a smooth functional is obtained in a bounded convex conical set deï¬ned by a norm and a concave upper semicontinuous functional. The technique is then used for the localization and multiplicity of Nash equilibrium solutions of nonvariational systems. Applications are given to periodic problems.