New numerical schemes for extreme geophysical phenomena
The GeoNum project aims at deriving high-order numerical methods to approximate nonlinear hyperbolic systems that arise when considering gravitational flows. The objectives are twofold. On the one hand, relevant models have to be carefully chosen in order to perform simulations of physical interest. Indeed, geophysical flows are generally modelled using Saint-Venant equations, which are not systematically well adapted to predict sophisticated shallow water flows. These models have to be extended to take into account important phenomena including turbulence, complex bathymetries or the sediments' impact on the topography's variation. On the other hand, the developments of new strategies to enforce highly accurate approximations required to simulate environmental flows are considered. Moreover, a particular attention must be paid on the robustness of the suggested algorithms. To address such an issue, classical schemes have to be extended into relevant high order approximations independently of both chosen topography and domain geometry. As a consequence, the resulting approaches are well adapted to perform real-life simulations.
Cette journée a pour objectif d'informer les mathématicien-ne-s rennais-es sur le paysage de l'édition scientifique mathématique actuel et ses évolutions en cours. Elle ambitionne également de stimuler des comportements vertueux des individus et des structures en matière de publication d'articles et d'utilisation des ressources documentaires.
09:30-10:30 Frédéric Hélein, Le paysage actuel de l'édition scientifique
10:30-11:30 Thierry Bouche, Présentation du Cedram et autres nouvelles initiatives
11:30-12:30 Laurent Guillopé, La SMF comme maison d'édition
14:00-15:00 Reinie Erné et Bas Edixhoven, La Fondation Compositio Mathematica
15:00-16:00 Claude Sabbah, Un exemple de journal électronique, le Journal de l'Ecole Polytechnique
Maryse Collin, Matthieu Romagny (organisateurs principaux), Xavier Caruso, Françoise Dal'Bo, Michel Gros, Frank Loray, Florian Méhats, Christophe Mourougane, Nicolas Raymond, San Vũ Ngọc
Tous les exposés ont lieu dans la salle 004-006, au rez-de-chaussée de l'IRMAR.
Organization board: Sébastien Boucksom, Yann Rollin, Carl Tipler
Scientific board: Claudio Arezzo, Olivier Biquard, Paul Gauduchon, Michael Singer
Kähler geometry is a very active research field, at the crossroads between algebraic and Riemannian geometry. Important breakthrough, that lead to solve the Yau-Tian-Donaldson conjecture in the Fano case, have been achieved recently. A spring school involving mini-lectures and talks around this thread of new ideas in Kähler geometry is organized at Nantes University. The goal of the school is to develop certain technical skills, useful to address a variety of important questions in algebraic geometry and global analysis on manifolds, aimed for PhD students and young researchers. Geometric flows, like the Kähler-Ricci flow for instance, and the associated quantification by the Donaldson dynamical system, will be among the essential tools dealt with during the school.
Conference - Teichmüller Theory in Higher Dimension and Mirror Symmetry
Organization board: Yves Coudène, François Maucourant, Françoise Pène, Barbara Schapira, Samuel Tapie
Scientific board: Jon Aaronson, Jean-Pierre Conze, Gilles Courtois, Domokos Szasz
This conference will focus on dynamical systems which naturally preserve a measure with infinite mass. These systems appear in a geometric or probabilistic context, or may come from natural sciences. When the invariant measure has infinite mass, recurrence is no longer automatic, usual mixing properties disappear and new asymptotical properties (such as rationnal ergodicity) may occur. Such systems may develop various and subtil behaviours, which could not exists in finite measure dynamics.
This conference will gather international experts on this topic, and will allow young researcher to have an easy access to the large recent developpment on such questions.
Conference - Dynamics of algebraic transformations
This summer school took place at the Faculté des Sciences et Techniques, Université de Nantes, from June, 22nd to July, 3rd, 2015. The organization committee is the following : Erwan Faou, Benoît Grébert, Eric Paturel
Mini-courses and talks have been captured and are available
Presentation of the field
If normal forms were initially used in a finite dimensional setting, for a better understanding of the long time behavior of dynamical systems, their extension to partial differential equations, especially in the nonlinear case, have led to important progresses during this last decade. More than useful tools, they put in light some characteristic phenomena in complex situations where nonlinearity play a fondamental rôle. The aim of this summer school is to show their great adaptability in various fields (Hamiltonian PDEs, fluid mechanics, numerical analysis), and to explain how it works, in a manner accessible to starting researchers.