Orateur: Stefan Friedl (Regensburg)
Titre: The Thurston norm for 3-manifolds with a 2-generator 1-relator group.

Résumé: If the fundamental group of a 3-manifold admits a presentation with two generators and one relator we will show that one can obtain the Thurston norm, i.e. the minimal complexity of embedded surfaces, directly from the presentation. This is based on work with Kevin Schreve and Stephan Tillmann.