We show that any space with a positive upper curvature bound has in a small neighborhood of any point a closely related metric with a negative upper curvature bound.

中文翻译：

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曲率上限的改进

我们表明，任何具有正上曲率界限的空间在任何点的小邻域中都有一个密切相关的度量，其具有负上曲率界限。