English

Nilpotent groups and biLipschitz embeddings into $L^1$

Metric Geometry 2021-12-22 v1 Analysis of PDEs Differential Geometry Functional Analysis Group Theory

Abstract

We prove that if a simply connected nilpotent Lie group quasi-isometrically embeds into an L1L^1 space, then it is abelian. We reach this conclusion by proving that every Carnot group that biLipschitz embeds into L1L^1 is abelian. Our proof follows the work of Cheeger and Kleiner, by considering the pull-back distance of a Lipschitz map into L1L^1 and representing it using a cut measure. We show that such cut measures, and the induced distances, can be blown up and the blown-up cut measure is supported on "generic" tangents of the original sets. By repeating such a blow-up procedure, one obtains a cut measure supported on half-spaces. This differentiation result then is used to prove that bi-Lipschitz embeddings can not exist in the non-abelian settings.

Keywords

Cite

@article{arxiv.2112.11402,
  title  = {Nilpotent groups and biLipschitz embeddings into $L^1$},
  author = {Sylvester Eriksson-Bique and Chris Gartland and Enrico Le Donne and Lisa Naples and Sebastiano Nicolussi-Golo},
  journal= {arXiv preprint arXiv:2112.11402},
  year   = {2021}
}
R2 v1 2026-06-24T08:26:40.918Z