English

The Carnot-Carath\'eodory distance on $2$-step groups

Classical Analysis and ODEs 2021-12-16 v1 Differential Geometry

Abstract

Combining Varadhan's formula, Loewner's theorem with the method of stationary phase, we study the exact formula of the Carnot-Carath\'eodory distance on 22-step groups. The method is also adapted to determine all normal geodesics from the identity element to any given point (up to a set of measure zero). As an application, we characterize the squared sub-Riemannian distance as well as the cut locus on generalized Heisenberg-type groups and on star graphs respectively. Furthermore, the long-standing open problem of Gaveau-Brockett is completely solved in the case of N3,2N_{3, 2}, the free Carnot group of step two and 3 generators.

Cite

@article{arxiv.2112.07822,
  title  = {The Carnot-Carath\'eodory distance on $2$-step groups},
  author = {Hong-Quan Li},
  journal= {arXiv preprint arXiv:2112.07822},
  year   = {2021}
}

Comments

52 pages, 3 figures. The main results of this paper, combined with the main results in arXiv:2102.09860 and recent progress, should be included in a single forthcoming paper

R2 v1 2026-06-24T08:17:42.681Z