Riemannian geometry on the diffeomorphism group of the circle
The topological group D-k(S) of diffeomorphisms of the unit circle 5 of Sobolev class H-k, for k large enough, is a Banach manifold modeled on the Hilbert space H-k(S). In this paper we show that the H-1 right-invariant metric obtained by right-translation of the H-1 inner product on TidDk(S)similar or equal to H-k(S) defines a smooth Riemannian metric on D-k(S), and we explicitly construct a comp