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  • Post-doc positions
    Oct 4, 2017 to Dec 1, 2017
    lebesgue_money.png Henri Lebesgue Center offers post-doc positions for researchers in mathematics.


    The Lebesgue Center and its partners, Région Bretagne & Région Pays de la Loire (DéfiMaths project), are opening applications for three post-doctoral positions in mathematics for a period of 2*12 months. The hired applicant will conduct his/her research at one of these Insitutes:

    Irmar of Rennes
    LMJL of Nantes
    LMBA of Brest and Vannes
    LAREMA of Angers

    The positions are open to all research areas present within the four Institutes. They do not include an obligation to teach.

    The net salary will be 2 100 Euros per month.


    The application is open.

    Sending application: between the 4th of October 2017 and the 1st of December 2017.

    The positions are expected to begin on September 1st or October 1st, 2018.


    Candidates must have completed a PhD in mathematics, or equivalent, at the date of taking office. The candidate must submit an original research project including a collaboration with one or more local researcher (s) of Irmar, LMJL,LMBA, or LAREMA.

    Applicants must complete the online form where they have to join the following documents:

    • CV describing the candidate's profile and professional experience (list of publications, research topics, activities)
    • Cover letter including the research project
    • At least two letters of recommendation, including one from the local researcher involved in the project

    For more information, please contact us at post-doctorant[at]


    The selection is carried by the Lebesgue Scientific Committee.



  • Complex dynamics and quasi-conformal geometry
    Oct 23, 2017 to Oct 25, 2017

    Our colleague Tan Lei passed away in April 2016. A conference will be held from 23/10/2017 to 25/10/2017 at the University of Angers to honour her memory.

    Scientific Committee

    Etienne Ghys (ENS Lyon)
    John Milnor (Stony Brook)
    Mitsuhiro Shishikura (Kyoto).

    Organizing Committee

    Mohammed El Amrani (Angers)
    Michel Granger(Angers)
    Jean-Jacques Loeb(Angers)
    Laurent Meersseman(Angers)
    Pascale Roesch(Toulouse).

    Provisional list of speakers

    Xavier Buff, Arnaud Cheritat, Nuria Fagella (to be confirmed), Cui Guizhen,Peter Haissinski, John Hamal Hubbard (to be confirmed), Carsten lunde Petersen, Kevin Pilgrim, Mary Rees, Pascale Roesh, Hans Henrik Rugh, Dylan Thurston, Mitsu Shishikura, Giulio Tiozzo.

    More information : page

    The registration process is already open.

  • 5 minutes Lebesgue
    Oct 24, 2017

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

    Prochain exposé (rediffusion):

    24-10-2017:  Vincent Colin
    Comment mesurer la forme d'un espace ?

    Comment construire des espaces exotiques aux propriétés surprenantes et comment, par des expériences locales, en deviner la forme ? On se laissera guider par Henri Poincaré.



    Exposés à venir:

    07-11-2017:  Éric Hazane

    21-11-2017:  Marine Fontaine

    28-11-2017:  Roger Lewandowski

    05-12-2017:  Maria Cumplido

    19-12-2017:  Guy Casale

    06-02-2018:  Rozenn Texier-Picard

  • Séminaire Quimpériodique
    Nov 16, 2017 to Nov 17, 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.


    Sorin Dumitrescu (Univ. Nice): Géométries de Cartan branchées
    Clément Fromenteau (LAREMA): Sur le champ de Teichmüller des surfaces de Hopf
    Ngoc-Phu Ha (LMBA Vannes): Invariants quantiques associés à la super-algèbre de Lie sl(2|1)
    Harold Rosenberg (IMPA): The geometry and topology of complete minimal surfaces and applications
    Caroline Vernier (LMJL): Théorèmes de recollement en géométrie Kählérienne


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


    Historique du séminaire


    Télécharger l'affiche ici

  • School - Masterclass 2017
    Dec 19, 2017 to Dec 21, 2017


    Angers, from December 19th to December 21st

    Organization board: Etienne Mann

    We organize a masterclass in Angers, from 19th to 21st of December, 2017. Lectures will be in the morning sessions. We will have two parallel sessions:

    • Etienne Mann : Introduction to algebraic stacks
      We will introduce the notion of fibered category, Grothendieck topology and stacks. We will illustrate these notions on simple examples. These lectures are for Master (or PhD) students who had followed a introduction to algebraic geometry that is algebraic varieties and sheaves.
    • Loic Chaumont: Application of the matrix-tree-theorem

    The organisation board will pay the housing and the lunch. The other meals are not payed by the organizers. For the travel expenses, we will do our best in the limit of our budget.

    Date limite d'inscription 15 novembre.

  • Workshop - Numerical methods for algebraic curves
    Feb 19, 2018 to Feb 23, 2018


    Rennes, from February 19th to February 23rd

    Organization board: Xavier Caruso, David Lubicz, Christophe Ritzenthaler, Marie-Françoise Roy

    This workshop will bring together researchers in complex and real algebraic geometry and applied mathematics (physics and cryptography) to discuss numerical methods and open problems on algebraic curves. There will be a number of introductory talks to each of the following topics and invited lectures from specialists: - Theoretical physics/DPE - Computations with the Jacobian - Random real topology - Complexity of computing topology of real algebraic curves - p-adic methods and applications to cryptography

  • Conference - Mathematics and Entreprises Days
    Apr 12, 2018 to Apr 13, 2018


    Vannes, from April 12th to April 13th

    Organization board: Christophe Berthon, Eric Darrigrand, Emmanuel Frénod, Fabrice Mahé, Loïc Chaumont

  • School - Fundamentals and practice of finite elements
    Apr 16, 2018 to Apr 20, 2018


    Roscoff, from April 16th to April 20th

    Organization board: Martin Costabel, Eric Darrigrand, Monique Dauge, Yvon Lafranche

    Scientific board: Monique Dauge (Univ. Rennes 1), Ilaria Perugia (TU Wien)

Saturday, January 28, 2017

All day
Before 01
Conference - CAST - Contact and Symplectic Topology
Jan 26, 2017 to Jan 28, 2017


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

Jan 28, 2017

Manolescu and Woodward defined homology groups associated to a closed connected oriented 3-manifold, called symplectic instanton homology, using Lagrangian Floer homology inside a moduli space of flat SU(2)-connexions associated to a punctured Heegaard surface. Using Wehrheim and Woodward's "Floer field theory" and pseudo-holomorphic quilts, I will show that these groups only depend on the choice of a basepoint, and will define maps associated to a smooth 4-dimensional cobordism equipped with a path.

Jan 28, 2017

In recent work, Baldwin and I defined invariants of contact 3-manifolds with boundary in sutured instanton Floer homology. I will sketch the proof of a theorem about these invariants which is analogous to a result of Plamenevskaya in Heegaard Floer homology: if a 4-manifold admits several Stein structures with distinct Chern classes, then the invariants of the induced contact structures on its boundary are linearly independent. As a corollary, we conclude that if a homology sphere Y admits a Stein filling which is not a homology ball, then its fundamental group admits a nontrivial representation to SU(2). This is joint work with John Baldwin.

Jan 28, 2017

Given a Lagrangian two-torus with an attached Lagrangian disk, one can construct a different Lagrangian torus by a procedure called mutation. I will talk about the wall-crossing formula which describes how the enumerative geometry of holomorphic Maslov index 2 disks changes under mutation. I will also mention higher-dimensional mutations, and the wall-crossing formula for them. This is joint work with James Pascaleff.





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