From Birational Transformations to Regular Automorphisms

Birational transformations may contract hypersurfaces, may have Indeterminacy points, ... I shall describe an argument which, starting with such a group of birational transformations, provides a way to conjugate this group to a group of (pseudo)- automorphisms. This argument applies to a class of groups which appears in the study of cubical complexes.
(This talk is based on a joint work with Yves de Cornulier.)