Atelier de Géométrie Arithmétique - 数論幾何学のアトリエ 2024

Around the Grothendieck-Teichmüller group

The Grothendieck-Teichmüller group GT, first introduced by Drinfel'd and Ihara in the 90s, follows Grothendieck's insight of ``Esquisse d'un programme'' to encapture the absolute Galois group of rational numbers in a combinatorial way, via topological group properties, within the outer automorphism group of a certain category of tower of étale fundamental groupoids. Recent breakthroughs were obtained, on the topological side (via operads, see Fresse-Horel ~2012) and on the arithmetic side (via combinatorial anabelian geometry, see Hoshi-Minamide-Mochizuki ~2017).

The goal of this workshop is to provide an arithmetical construction of the Grothendieck- Teichmüller group such as given by Ihara, and a practical understanding of the anabelian and geometric methods used by Hoshi, Minamide and Mochizuki to provide recent results on GT. We refer to the program for a description of talks and a list of references.

This atelier is organized with the support of the École Parisienne d'Arithmétique et de Géométrie (ÉPAG).

Registation [opened]

Would you be interested in attending or giving a talk, please register here.

Antonin Assoun Université de Lille Paris
Elias Caerio École Normale Supérieure PSL Paris
Lucas Dauger Sorbonne Université Paris
Mattias Ferreira-filoramo Sorbonne University Paris Paris
Shun Ishii Keio University Kyoto
Yuki Kondo Osaka University Kyoto
Kaiji Kondo RIMS Kyoto University Kyoto
Brieuc Lair École Normale Supérieure PSL Kyoto
Louis Loiseau Université de Nantes Paris
Maxime Lombard Université de Nantes Paris
Séverin Philip RIMS Kyoto University Kyoto
Densuke Shiraishi Osaka University Kyoto
Jianbo Sun Kyushu University Kyoto
Reiya Tachihara RIMS Kyoto University Kyoto
Naoka Takada Osaka University Kyoto
Nikola Tomic Université de Montpellier Paris
Shiyuan Wan University of Bordeaux Paris
Naganori Yamaguchi Tokyo Institute of Technology Kyoto
*In progress... Kyoto: 10; Paris: 8...Updated: Nov.28, 2023

The Atelier takes place in-person with a Zoom bridge between RIMS Kyoto and Paris. Participants proposes and vote for the next Atelier topic.

You can also contact one of the organizers -- M. Ferreira-Filoramo (France), S. Philip (RIMS JP) or N. Yamaguchi (Tokyo JP).