Scars for arithmetic point scatterers on the torus
16 janvier 2020 @ 14:30 – 15:30 – Résumé
From generative models of protein sequences to evolution-guided protein design
16 janvier 2020 @ 10:45 – 11:45 – Thanks to the sequencing revolution in biology, protein sequence databases have been growing exponentially over the last years. Data-driven computational approaches are becoming more and more popular in exploring this increasing data richness. In my talk, I will show that global statistical modeling approaches, like (Restricted) Boltzmann Machines are able to accurately capture the natural […]
Le problème de Dirichlet sur des domaines singuliers
14 janvier 2020 @ 14:00 – 15:00 – Le problème de Dirichlet sur un domaine lisse et borné (Omega subset mathbb{R}^n) est bien posé : il existe toujours une unique solution, et celle-ci possède la plus grande régularité possible. Lorsque (Omega) n’est pas lisse, par exemple pour un polyhèdre, cette dernière propriété n’est plus vraie. En faisant un changement de variable qui envoie […]
Sensitivity analysis for identification of voids under Navier’s boundary conditions in linear elasticity
14 janvier 2020 @ 10:45 – 11:45 – This talk is concerned with a geometric inverse problem related to the two-dimensional linear elasticity system. Thereby, voids under Navier’s boundary conditions are reconstructed from the knowledge of partially over-determined boundary data. The proposed approach is based on the so-called energy-like error functional combined with the topological sensitivity method. The topological derivative of the energy-like […]
Décroissance du nombre de zéros des solutions d’une équation parabolique
14 janvier 2020 @ 09:15 – 10:15 – Résumé
Représentations milnoriennes et non-milnoriennes
13 janvier 2020 @ 14:00 – 15:00 – En 1977, Milnor a formulé la conjecture suivante : tout groupe discret de transformations affines agissant proprement sur l’espace affine est virtuellement résoluble. On sait maintenant que cet énoncé est faux. L’objectif est à présent de mieux cerner les contre-exemples à cette conjecture. Chaque groupe qui viole cette conjecture « vit » dans un certain groupe affine […]
Maximal determinants of Schrödinger operators on finite intervals
9 janvier 2020 @ 14:15 – 15:15 – In this talk I will present the problem of finding extremal potentials for the functional determinant of a one-dimensional Schrödinger operator defined on a bounded interval with Dirichlet boundary conditions. We consider potentials in a fixed $L^q$ space with $qgeq 1$. Functional determinants of Sturm-Liouville operators with smooth potentials or with potentials with prescribed singularities […]
Stochastic Analysis of the Neutron Transport Equation
9 janvier 2020 @ 10:45 – 11:45 – The neutron transport equation (NTE) describes the net movement of neutrons through an inhomogeneous fissile medium, such as a nuclear reactor. One way to derive the NTE is via the stochastic analysis of a spatial branching process. This approach has been known since the 1960/70s, however, since then, very little innovation in the literature has […]
Barak-Erdös graphs and the infinite-bin model
9 janvier 2020 @ 09:15 – 10:15 – Barak-Erdös graphs are the directed acyclic version of Erdös-Rényi random graphs : the vertex set is {1,…,n} and for each i<j with probability p we add an edge directed from i to j, independently for each pair i0 and is differentiable once but not twice at p=0. We also show that the coefficients of the […]
Curves on K3 surfaces
6 janvier 2020 @ 15:30 – 16:30 – Bogomolov and Mumford proved that every projective K3 surface contains a rational curve. Since then, a lot of progress has been made by Bogomolov, Chen, Hassett, Li, Liedtke, Tschinkel and others, towards the stronger statement that any such surface in fact contains infinitely many rational curves. In this talk I will present joint work with […]