Geometry and Curvature of Shape Spaces

Peter Michor

Abstract: Here Shape space consists of either: sets of ordered points on Rn (landmark space), submanifolds of Rn, even certain currents in Rn. The group of diffeomorphisms with compact support acts transitively on shape space, and we induce Riemannian metrics on shape space induced from right invariant Sobolev metrics in the diffeomorphism groups. This offers interesting analytical difficulties. The resulting geodesic equations are well posed. Curvature can be computed in two ways: directly, or via O'Neill's formula from Arnold's curvature on the diffeomorphism group.