A. Alvarez: Howson's theorem in the context of measured equivalence relations.

Abstract: Howson's theorem states that the intersection of two finitely generated groups in a free group is finitely generated. Can we hope such a result in the context of measured equivalence relations? I will recall definitions about measured equivalence relations, treeability and the notion of cost developped by Gaboriau and I will present ideas towards a proof of a 'Howson's theorem' version.