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  • 5 minutes Lebesgue
    Mar 28, 2017

    Les vidéos des exposés seront mises en ligne quelques jours après l'exposé. Vidéothèque

    Prochain exposé : Rediffusion :

    28-03-2017:  Marc Raynaud La machine de Turing

    Lieu

    Rennes

    Exposés à venir:

    04-04-2017:  Barbara Schapira

    25-04-2017:  Basile Pillet

  • XVI Journées Louis Antoine
    Mar 30, 2017 to Mar 31, 2017

    Statistiques : regret et parcimonie

    Deux mini-cours de 3 heures

    Gilles Stoltz (CNRS, HEC): Bandits stochastiques avec un nombre fini de bras : résultats d'optimalité sur le regret.

    et

    Sara van de Geer (ETH Zürich) :Estimation and testing under sparsity.

    et un exposé complémentaire

    Cyril Lacoste (Université de Rennes 1): Statistiques et sommes de trois carrés.

    Voir le site des JLA

  • School - Flows and Limits in Kähler Geometry
    Apr 18, 2017 to Apr 22, 2017

    Nantes, from April 18th to April 22nd

    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
    Apr 24, 2017 to Apr 28, 2017

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    Angers, from April 24th to April 28th

    Organization board: Frédéric Mangolte, Etienne Mann, Laurent Meersseman, Alexis Roquefeuil

    Teichmüller theory and mirror symmetry are very active domains. In this conference, we propose two series of lectures by two world leader mathematicians :

    • Misha Verbitsky on Teichmüller theory
    • Dimitri Zvonkine, University Pierre et Marie Curie

    Speakers:

    • Gaetan Borot, Max Planck Institut, Bonn
    • Fabrizio Catanese, University of Bayreuth
    • Ekaterina Amerik, University of Orsay (tbc)
    • Maxim Kontsevich, IHES (tbc)
    • Thomas Reichelt, University of Heidelberg
    • Jacopo Stoppa, SISSA
    • Claude Sabbah, Ecole polytechnique
    • Adrien Sauvaget, University Pierre et Marie Curie
    • Andrei Teleman, University of Aix-Marseille
  • Séminaire Quimpériodique
    Jun 1, 2017 to Jun 2, 2017

    Ce séminaire de géométrie, complètement à l'Ouest, réunit à Quimper, trois fois l'an, pour deux journées, le jeudi et le vendredi, des géomètres venus des régions Bretagne et Pays de Loire.

    Programme

    Inas Amacha (LMBA): TBA;
    Vincent Colin (LMJL): TBA;
    Bertrand Deroin (ENS Paris): TBA;
    Victor Kleptsyn (IRMAR): TBA;
    Paul Laurain (univ. Paris VII): TBA.

    Correspondants

    Guillaume Deschamps, LMBA, Brest
    Laurent Meersseman, LAREMA, Angers
    Gaël Meigniez, LMBA, Vannes
    Yann Rollin, LMJL, Nantes
    Frédéric Touzet, IRMAR, Rennes

    Historique

    Historique du séminaire

    Affiche

    Télecharger l'affiche ici

  • Conference - Infinite measure Dynamics
    Jun 6, 2017 to Jun 9, 2017

    Brest, from June 6th to June 9th

    Organization board: Yves Coudène, François Maucourant, Françoise Pène, Barbara Schapira, Samuel Tapie, Annick Nicolle

    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 - Families of algebraic dynamical systems
    Jun 12, 2017 to Jun 16, 2017

    Rennes, from June 12th to June 16th

    Organization board: Serge Cantat, Christophe Dupont

    Scientific board: Matthew Baker, Eric Bedford, Serge Cantat, Christophe Dupont, Mattias Jonsson

  • Conference - Random walks on algebraic structures-On honour of Yves Guivarc'h
    Jun 19, 2017 to Jun 23, 2017

    Rennes, from June 19th to June 23rd

    Organization board: Bachir Bekka, Nizar Demni

    Scientific board: Bachir Bekka, Emmanuel Breuillard, Nizar Demni, Alex Lubotzky

    The conference deals with themes around random walks on algebraic structures. Dynamical sytems on groups, homogeneous spaces, and related structures (graphs, quantum groups , groupoids,...) are rich objects, involving various fields of mathematics (probability, group theory, topology, number theory, operator algebras, Banach space geometry, etc). They are also useful as modelling tools for other sciences (physics, computer science, economics, etc); for instance, expander graphs, which are of interest in theoretical computer science, are graphs for which the associated random walk has special spectral properties and their explicit construction involves sophisticated tools such as Kazhdan's property (T) or Selberg's inequality. The conference aims to give a flavor of the various aspects of the subject by bringing together some experts with major contributions to the field. This conference will also be the opportunity to celebrate the 80th birthday of Yves Guivarc'h, who played a major part in the development of probability on algebraic and geometric structures, a subject with an ever growing interest for the last 30 years.

Friday, January 27, 2017

All day
Conference - CAST - Contact and Symplectic Topology
Jan 26, 2017 to Jan 28, 2017
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Download the poster in pdf

Nantes, from January 26th to January 28th

Organization board: Baptiste Chantraine, Vincent Colin, Paolo Ghiggini

Scientific board: Jean-François Barraud, Baptiste Chantraine, Kai Cieliebak, Tobias Ekholm

 
 
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Sylvan
Jan 27, 2017

I'll define a "partially wrapped" Fukaya category associated to a Liouville domain with "stops", which are Liouville hypersurfaces of the boundary. This category is closely related to Legendrian contact homology [Ekholm--Lekili, 1701.01284]. I'll explain how certain functors between partially wrapped Fukaya categories, when they exist, can give strong constraints on the structure of Legendrian contact homology. This existence can in some cases be inferred from mirror symmetry, and in general it conjecturally follows from the existence of certain positive loops.

 
 
Vertesi
Jan 27, 2017

Knot Floer homology is an invariant for knots and links defined by Ozsvath and Szabo and independently by Rasmussen. It has proven to be a powerful invariant e.g. in computing the genus of a knot, or determining whether a knot is fibered. In this talk I define a generalisation of knot Floer homology for tangles; Tangle Floer homology is an invariant of tangles in D^3, S^2xI or in S^3. Tangle Floer homology satisfies a gluing theorem and its version in S^3 gives back a stabilisation of knot Floer homology. Finally, I will discuss how to see tangle Floer homology as a categorification of the Reshetikhin-Turaev invariant for the Alexander polynomial.

 
 
Orantin
Jan 27, 2017

Together with Bertrand Eynard, we developed a formalism allowing to compute the asymptotic expansion of a large class of matrix integrals when the matrix is very large. We later generalized this inductive formalism under the name topological recursion as an efficient way to solve many different problems related to enumerative geometry such as the computation of Gromov-Witten invariants of different manifolds, of the Weil-Petersson volume of moduli spaces of Riemann surfaces, of intersection numbers, Hurwitz numbers or sums over (plane-)partitions. It is also believed to generalize the volume conjecture by computing many knot invariants.

Even if a full general and geometric understanding of this success is still missing, I will present in this talk a brief introduction of the original formalism and its applications as well as a new point of view recently pointed out by Kontsevich and Soibelman presenting it as a way to quantize quadratic Lagrangians by providing the full WKB expansion of the associated wave function.

 
 
 
 
 
 
Wand
Jan 27, 2017

The modern development of contact geometry in 3 dimensions has seen several (due to Giroux, Wendl, Latschev and Wendl, Hutchings, and others) invariants of contact structures meant in some sense to measure non-(Stein/symplectic)-fillability of the structure. We will discuss a new approach which uses Heegaard Floer homology to define an invariant with a similar aim, but which has several desirable properties lacking in earlier approaches. Time permitting, we will discuss some examples and applications. This is joint with joint work with Kutluhan, Matic, and Van Horn-Morris.

 
 
 
 
Simone
Jan 27, 2017

Let (W; L, L') be a monotone Lagrangian cobordism. In some cases, for example when the minimal Maslov number of W is big enough, the fundamental groups of L and L' give a lot of information about the topology of $W$. Motivated by this question, we study the fundamental group of W using two approaches: a geometric approach based on Barraud's construction of the Floer fundamental group and an algebraic approach using Floer homology with local coefficients. This talk is based on a joint work with Jean-François Barraud.

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

Partners

Irmar LMJL ENS Rennes LMBA LAREMA

Affiliation

ANR CNRS Rennes 1 Rennes 2 Nantes INSA Rennes INRIA ENSRennes UBO UBS Angers UBL