English

Incidences among flows

Classical Analysis and ODEs 2025-09-12 v1 Combinatorics

Abstract

We consider two incidence problems for integral curves of vector fields. The first is an analogue of the Euclidean joints problem, in which lines are replaced by integral curves of smooth vector fields taken from some finite-dimensional set. The second is a bilinear and more rigid version of the first, in which we have two vector fields and one family of integral curves tangent to each and wish to know how many intersecting pairs are possible. In both cases, a curvature condition of H\"ormander makes possible nontrivial bounds on the number of incidences in terms of the number of curves.

Keywords

Cite

@article{arxiv.2509.08937,
  title  = {Incidences among flows},
  author = {Kaiyi Huang and Betsy Stovall and Sarah Tammen},
  journal= {arXiv preprint arXiv:2509.08937},
  year   = {2025}
}

Comments

21 pages

R2 v1 2026-07-01T05:30:52.366Z