Séminaire Francilien de Géométrie Algorithmique et Combinatoire

Le Séminaire de Géométrie Algorithmique et Combinatoire vise à regrouper des exposés dans ce domaine au sens le plus large, et dans les disciplines connexes en mathématiques et informatique. Il est ouvert à tous les chercheurs et étudiants intéressés. Les exposés sont destinés à un public large.

On reprend les activités en presentiel un jeudi tous les deux mois à 14h, à l'IHP.

Pour recevoir les annonces de ce séminaire, envoyer un message à arnaud [dot-sign] de-mesmay [the-funny-at-sign] univ-eiffel [dot-sign] fr

La liste des exposés passés est disponible ici.


22 février 2024

salle Maurice Fréchet (ex salle 05)

14h00 Kate VOKES University of Luxembourg
Geometry of graphs of multicurves
In recent years, a major technique in studying hyperbolic surfaces is to look at certain graphs associated to the surface which are defined from the combinatorics of curves on the surface. The graphs we study are typically locally infinite, and can sometimes serve as a discrete model for a continuous space, such as the Teichmuller space of the surface. Often we are interested in the large-scale geometry of these graphs: roughly speaking, we care about what the graph looks like when we view it from far away. An example of a large-scale geometric property is Gromov hyperbolicity. We will give an introduction to graphs of multicurves and present a result classifying large-scale geometric properties of a family of these graphs in terms of a simple criterion.
15h30 Alexandros Eskenazis CNRS-Sorbonne Université-Trinity College
Dimensionality of Hamming metrics and Rademacher type
I shall present a lower bound on the bi-Lipschitz distortion required to embed the Hamming cube into a low-dimensional normed space. This unifies and extends (almost) all known results on the impossibility of dimensionality reduction for the hypercube metric. The proof relies on a combination of semigroup techniques on the biased cube with the Borsuk-Ulam theorem from algebraic topology.

Le séminaire bénéficie du soutien de l'Institut Henri Poincaré.

Le comité d'organisation est constitué de Alfredo Hubard, Arnaud de Mesmay et Lionel Pournin.