Dessins d'enfants and the Grothendieck-Teichmüller group
Event details
| Date | 01.12.2015 |
| Hour | 15:15 › 17:00 |
| Speaker | Pierre Guillot, (Strasbourg) |
| Location | |
| Category | Conferences - Seminars |
During the first part of the talk I will describe the
theory of dessins d'enfants, which states the equivalence of a number
of seemingly quite different categories, such as graphs embedded on
surfaces, étale algebras over a field of rational fractions (with
various coefficients), or finite sets endowed with two distinguished
permutations. It follows that the absolute Galois group of QQ acts on
all these categories, and one can show that the action is faithful.
As a result, this Galois group injects into the
Grothendieck-Teichmüller group, of which I will give an elementary
description. In the second part of the talk, I shall explain how to
make concrete calculations, and propose a few open questions.
theory of dessins d'enfants, which states the equivalence of a number
of seemingly quite different categories, such as graphs embedded on
surfaces, étale algebras over a field of rational fractions (with
various coefficients), or finite sets endowed with two distinguished
permutations. It follows that the absolute Galois group of QQ acts on
all these categories, and one can show that the action is faithful.
As a result, this Galois group injects into the
Grothendieck-Teichmüller group, of which I will give an elementary
description. In the second part of the talk, I shall explain how to
make concrete calculations, and propose a few open questions.
Practical information
- Informed public
- Free