Journées Hyperstructures, Topological Data Analysis and Multicellularity (17-18 mars 2020)


Hyperstructures, Topological Data Analysis and Multicellularity

march 17-18, 2020


This two days conference is the starting event of a transdisciplinary project aiming to bring together experts in mathematical biology, data analysis and topology to study multicellular organisms. Those are, among living systems, those whose complexity, due to a multiplicity of intricate levels of description from an integrated physiology point of view, makes their study seldom satisfactory as soon as one aims to fix issues evidenced as malfunctions, the major of them in a medical perspective being cancer.  The idea behind the whole project is  to shed light on this question both from a theoretical viewpoint by a description of multicellular organisms in terms of higher structures, which integratefunction (semantics) and matter (syntax) from lower to upper levels, and from an applied one by investigating existing data bases using methods of topological data analysis (TDA).  The conference itself will be dedicated to presenting to a broad audience and participants the  state of the art of ideas related to multicellular organisms, applications of topological data analysis, hypestructures, higher structures from topology and categorical methods.


Programme :    

    • Mardi 17 mars 2020 : 
      • 14h00-15h00 : Nils Baas (U. Trondheim).   "The Topology of Brain Cells"
      • 15h15-16h15 : Steve Oudot (INRIA - Ecole Polytechnique). "TBA "
      • 16h45-17h45 : François Petit (Université de Paris - CRESS). "TBA " 
    • Mercredi 18 mars 2020 :
      • 9h00-10h00 : Nils Baas (U. Trondheim).  "Hyperstructures in Mathematics and Biology"
      • 10h15-11h15 :  Jean Clairambault (INRIA - Sorbonne Université).  "Cancer as a default of coherence between tissues in metazoans: what mathematical models should be developed to help prediction, prevention and treatment of cancer ?"
      • 11h30-12h30 : Jean-François Mascari (Instituto per le Applicazioni del Calcolo "M. Picone" Consiglio Nazionale delle Ricerche Italie). " Functorial Semantics in Biology and Hyper-Structures"
      • 12h30-14h00 : Repas
      • 14h00 - 15h00: Grégory Ginot (Université Sorbonne Paris Nord). "Higher structures from Topological Field Theories "

 Lieu : Salle B407Institut Galilée.  Pour venir à Paris 13, et plus précisément à son Institut Galilée,  consulter la page (décrivant l'accès au laboratoire). 

Organisateurs: Grégory Ginot, Nathalie Tavares

Journées Combinatorics and Arithmetic for Physics (6-8 nov. 2019)

Journées Combinatorics and Arithmetic for Physics

6-8 novembre 2019

Le Bois-Marie, Centre de Conférences Marilyn et James Simons, 35, route de Chartres 91440 Bures-sur-Yvette
Informations complémentaires ici.

The meeting’s focus is on questions of discrete mathematics and number theory with an emphasis on computability. Problems are drawn mainly from theoretical physics (renormalisation, combinatorial physics, geometry) or related to its models.

Computation, based on combinatorial structures (graphs,trees, words, automata, semirings, bases) or classic structures (operators, Hopf algebras, evolution equations, special functions, categories) are good candidates for computer-based implantation and experimentation.

Organised by : Gérard H.E. Duchamp, Maxim Kontsevich, Gleb Koshevoy et Hoang Ngoc Minh

Invited speakers :

Nicolas Behr (Université de Paris, IRIF)
Marc Bellon (LPThE-Sorbonne-Univ., Paris and CNRS) 
Pierre Cartier (IHES)
Bérénice Delcroix-Oger (Sorbonne-Univ., IRIF) 
Gérard Duchamp (IHP and LIPN, Univ. Paris XIII) 
Thomas Fernique (CNRS and LIPN, Univ. Paris XIII) 
Stéphane Gaubert (INRIA and CMAP, École Polytechnique) 
Dima Grigoryev (CNRS Painlevé Lab, Univ. Lille) 
Dmitry Gurevich (Valenciennes Univ., France)
Richard Kerner (LPTMC, Sorbonne-Univ., Paris) 
Maxim Kontsevich (IHES)
Gleb Koshevoy (ISCP, Moscow)
Annie Lemarchand (LPTMC, Sorbonne-Univ., Paris) 
Léon Masurel (LPTMC, Sorbonne-Univ., Paris)
Vincel Hoang Ngoc Minh (Univ. Lille and LIPN, Univ. Paris XIII) 
Gabriel Morgado (LPTMC, Sorbonne-Univ., Paris) 
Frédéric Patras (LJAD, Univ. Côte d’Azur and CNRS) 
Karol A. Penson (LPTMC, Sorbonne-Univ., Paris) 
Vincent Rivasseau (LPT, Univ. Paris-Sud, Orsay)
Alan Sokal (University College London and New York University) 
Pierre Vanhove (IPhT CEA/Saclay, HSE)

Journée Cartes (9 avril 2019)


Lieu : Université Paris 13, Campus de Villetaneuse -- Venir à Paris 13
Les exposés auront eu lieu en salle B405 du LAGA, au 4ème étage du bâtiment B de l'Institut Galilée -- Plan du campus pour arriver au bâtiment B

Orateurs : Jérémie BettinelliLuis FredesErik SlivkenGuillaume Chapuy

Organisateurs : Valentin BonzomBénédicte HaasPhilippe Marchal

Soutien : FSMP.



  • 10h00-10h30: Café d'accueil
  • 10h30-11h30: Jérémie Bettinelli, Slit-slide-sew bijections for bipartite and quasibipartite plane maps
  • 11h30-12h30: Luis Fredes, TBA
  • 12h30-14h00: Déjeuner
  • 14h00-15h00: Erik Slivken, Square permutations are typically rectangles
  • 15h00-16h00: Guillaume Chapuy, Sur l'énumération asymptotique des triangulations coloriées de variétés d-dimensionnelles


  • Jérémie BettinelliSlit-slide-sew bijections for bipartite and quasibipartite plane maps
    We unify and extend previous bijections on plane quadrangulations to bipartite and quasibipartite plane maps. Starting from a bipartite plane map with a distinguished edge and two distinguished corners (in the same face or in two different faces), we build a new plane map with a distinguished vertex and two distinguished half-edges directed toward the vertex. The faces of the new map have the same degree as those of the original map, except at the locations of the distinguished corners, where each receives an extra degree. The idea behind this bijection is to build a path from the distinguished elements, slit the map along it, and sew back after sliding by one unit, thus mildly modifying the structure of the map at the extremities of the sliding path. This bijection provides a sampling algorithm for uniform maps with prescribed face degrees and allow to recover Tutte's famous counting formula for bipartite and quasibipartite plane maps.
    In addition, we explain how to decompose the previous bijection into two more elementary ones, which each transfer a degree from one face of the map to another face. In particular, these transfer bijections are simpler to manipulate than the previous one and this point of view simplifies the proofs.
  • Luis Fredes, TBA
  • Erik SlivkenSquare permutations are typically rectangles
    Square permutations are permutations were every point is a record (left or right, max or min). We give a simple algorithm that produces such an object (asymptotically almost surely) uniformly at random. From this algorithm we are able to give a description of interesting scaling limits and explore other generalizations. We show that a typical square permutation (properly scaled) looks like a random rectangle embedded in the unit square and specify the distribution of the rectangle. We can also describe the fluctuations about the rectangle in terms of coupled Brownian motions. This is based on joint work with Jacopo Borga.
  • Guillaume ChapuySur l'énumération asymptotique des triangulations coloriées de variétés d-dimensionnelles
    En dimension d>=3 on prend n simplexes, et on recolle leurs facettes de manière arbitraire. On obtient ainsi un espace topologique qui est a priori une pseudo-variété, mais pas toujours une variété. De combien de manières peut-on le faire, asymptotiquement, pour obtenir une variété? On donne des réponses (très) partielles à cette question sous la forme de bornes inférieures et supérieures superexponentielles. En particulier on détermine le comportement surexponentiel en dimension 3, dans le cas des triangulations coloriées issues des modèles de tenseurs. Au passage on croise des questions rigolotes et nouvelles d'énumération de graphes que nous laissons partiellement ouvertes. Travail en commun avec Guillem Perarnau.


Journée de Géométrie et Combinatoire dans les Espaces des Modules (24-25 septembre 2018)

Journées de Géométrie et Combinatoire dans les Espaces des Modules

24 et 25 Septembre 2018, Université Paris 13, campus de Villetaneuse

99 avenue Jean-Baptiste Clément, 93430 Villetaneuse (FRANCE)



Corentin Boissy (Toulouse)
Vincent Delecroix (Bordeaux)
Quentin De Mourgues (LIPN, Villetaneuse)
Giovanni Forni (Maryland)
Vaibhav Gadre (Glasgow)
Elise Goujard (Bordeaux)
Rodolfo Gutierrez (LAGA, Villetaneuse)
Carlos Matheus∗ (LAGA, Villetaneuse)

∗ = à confirmer.


À venir: programme, titres et abstracts des exposées.


Organisateurs: Luca MarcheseCarlos Matheus SantosThierry MonteilAndrea Sportiello.


Inscriptions: Pour s'inscrire, écrire à This email address is being protected from spambots. You need JavaScript enabled to view it.