English

Concurrent normals of immersed manifolds

Geometric Topology 2024-02-14 v2 Differential Geometry

Abstract

It is conjectured since long that for any convex body KRnK \subset \mathbb{R}^n there exists a point in the interior of KK which belongs to at least 2n2n normals from different points on the boundary of KK. The conjecture is known to be true for n=2,3,4n=2,3,4. Motivated by a recent results of Y. Martinez-Maure, and an approach by A. Grebennikov and G. Panina, we prove the following: Let a compact smooth mm-dimensional manifold MmM^m be immersed in Rn \mathbb{R}^n. We assume that at least one of the homology groups Hk(Mm,Z2)H_k(M^m,\mathbb{Z}_2) with k<mk<m vanishes. Then under mild conditions, almost every normal line to MmM^m contains an intersection point of at least β+4\beta +4 normals from different points of MmM^m, where β\beta is the sum of Betti numbers of MmM^m.

Keywords

Cite

@article{arxiv.2301.07742,
  title  = {Concurrent normals of immersed manifolds},
  author = {Gaiane Panina and Dirk Siersma},
  journal= {arXiv preprint arXiv:2301.07742},
  year   = {2024}
}