# Infinitesimal rigidity of convex surfaces: variational methods and duality

 Orateur: IZMESTIEV Ivan Localisation: , Allemagne Type: Séminaire de géométrie Site: Hors LAMA , IMJ P7 Salle: 0D1 Date de début: 20/02/2012 - 14:00 Date de fin: 20/02/2012 - 14:00

Both in the discrete and in the smooth context, we investigate two kinds of rigidity for surfaces in $\mathbb{R}^3$ : the one with respect to the induced metric (the first fundamental form) and the one with respect to the Gauss curvature parametrized by the Gauss map (the third fundamental form). We discuss two different duality relations between the both and connect variations of the volume to variations of the Hilbert-Einstein functional. This allows us to interpret Blaschke's proof of the infinitesimal rigidity of smooth convex surfaces in the spirit of Minkowski's proof of the infinitesimal rigidity in his theorem.