Gauss Equation and Injectivity Radii for Subspaces in Spaces of Curvature Bounded Above
نویسنده
چکیده
A Gauss Equation is proved for subspaces of Alexandrov spaces of curvature bounded above by K. That is, a subspace of extrinsic curvature ≤ A, defined by a cubic inequality on the difference of arc and chord, has intrinsic curvature ≤ K +A. Sharp bounds on injectivity radii of subspaces, new even in the Riemannian case, are derived.
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