Gareth Jones: Dessins d'enfants

Pozor: to je eden izmed dveh vzporednih kolokvijev!

This talk is an elementary introduction to Grothendieck's theory of dessins d'enfants (children's drawings). It describes how the combinatorial theory of maps on surfaces (specifically embeddings of bipartite graphs in compact orientable surfaces) can be used to characterise those Riemann surfaces which are defined as algebraic curves over the field of algebraic numbers. In particular, we obtain a combinatorial insight into the Galois theory of algebraic number fields.

Predavatelj: prof. dr. Gareth Jones, University of Southampton