Description:

Title: Dessins, G_Q, and (maybe) GT 

Abstract: In his Esquisse d'un Programme, Grothendieck suggests the study of Galois theory through geometric means. In particular, he suggests studying the absolute Galois group of the rationals by its action on various geometric objects, which lead to its comparison with (and conjectured equivalence to) the Grothendieck–Teichmüller group GT. This research proposal was part of an application for a position at CNRS in 1984. His application was rejected. 
In this talk I'll explain one of the ideas that inspired said proposal: the connection between dessins d'enfants (bi-coloured graphs on topological surfaces) and compact Riemann surfaces defined over number fields.

Note: The talk will start at 4:10 pm