Following the spirit of Grothendieck’s Esquisse d’un Programme, the Ihara/Oda-Matsumoto conjecture predicted a combinatorial description of the absolute Galois group of Q based on its action on geometric fundamental groups of varieties. This conjecture was resolved in the 90’s by Pop using anabelian techniques. In this talk, I will discuss the proof of stronger variant of this conjecture, using mod-ell two-step nilpotent quotients, while highlighting some connections with model theory.
- Séminaire Géométrie et théorie des modèles