The Moyal Sphere
  We construct a family of constant curvature metrics on the Moyal plane and compute the Gauss-Bonnet term for each of them. They arise from the conformal rescaling of the metric in the orthonormal frame approach. We find a particular solution, which corresponds to the Fubini-Study metric and which equips the Moyal algebra with the geometry of a noncommutative sphere. 
Micha{\l} Eckstein, Andrzej Sitarz, Raimar Wulkenhaar
math.QA hep-th math-ph math.MP