Differentiating maps into L1, and the geometry of BV functions
Differentiating maps into L1, and the geometry of BV functions
复制标题
将映射微分为 L1 和 BV 函数的几何
DOI:
10.4007/annals.2010.171.1347
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发表时间:
2006
影响因子:
4.9
通讯作者:
B. Kleiner
中科院分区:
文献类型:
--
作者:
J. Cheeger;B. Kleiner
This is one of a series of papers examining the interplay between differentiation theory for Lipschitz maps X → V and bi-Lipschitz nonembeddability, where X is a metric measure space and V is a Banach space. Here, we consider the case V = L 1 , where differentiability fails. We establish another kind of differentiability for certain X, including ℝ n and H, the Heisenberg group with its Carnot-Caratheodory metric. It follows that ℍ does not bi-Lipschitz embed into L 1 , as conjectured by J. Lee and A. Naor. When combined with their work, this provides a natural counterexample to the Goemans-Linial conjecture in theoretical computer science; the first such counterexample was found by Khot-Vishnoi [KV05]. A key ingredient in the proof of our main theorem is a new connection between Lipschitz maps to L 1 and functions of bounded variation, which permits us to exploit results on the structure of BV functions on the Heisenberg group [FSSC01].