Colloquium: Tuesday, May 12 2pm. Speaker: Mathieu Meyer, (Universite Paris Est-Marne la Vallee) . Title: Affine points of convex bodies.

In the Euclidean space E of dimension n; an affine invariant point (resp. set) on the class of convex bodies of dimension $n$, endowed with the Hausdorff metric, is a continuous map from this class into  E (resp. into itself ) which is invariant under one-to-one affine transformations  of E. Affine invariant points and sets appear to be  excellent tools to study the symmetry of a convex body. Answering a number of questions of Grunbaum, we define some new affine points and investigate the notion of dual affine points.

(joint work with C. Sch\”utt and E. M. Werner.)