Riemannian geometry of Diff(S1)/S1

The main result of the paper is a computation of the Ricci curvature of Diff(S1)/S1. Unlike earlier results on the subject, we do not use the Kähler structure symmetries to compute the Ricci curvature, but rather rely on classical finite-dimensional results of Nomizu et al. on Riemannian geometry of homogeneous spaces.