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Anton Petrunin
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Rauch's comparison local result, while Toponogov's comparison is global.

For the upper curvature bound an analog of Toponogov's comparison holds only locally and indeed it follows from Rauch's comparison. There is a gloabal version for upper comparison. For the curvature bound $\kappa\le 0$ it has an addition assumption that space is simply connected. If $\kappa>0$ then one has to assume that any closed curve shorter than $2\cdot\pi$ can be contracted in the class of closed curves shorter than $2\cdot\pi$.

Anton Petrunin
  • 45k
  • 14
  • 135
  • 299