A Blaschke hypersurface admits S symmetry if and only if S(X, Y) = S(Y, X). We prove that the shape operator has only one eigenvalue. And such Blaschke surfaces are classified as affine spheres or ruled surfaces.
文摘A Blaschke hypersurface admits S symmetry if and only if S(X, Y) = S(Y, X). We prove that the shape operator has only one eigenvalue. And such Blaschke surfaces are classified as affine spheres or ruled surfaces.