English

Homeotopy groups of one-dimensional foliations on surfaces

Geometric Topology 2017-10-19 v1 Complex Variables Differential Geometry General Topology

Abstract

Let ZZ be a non-compact two-dimensional manifold obtained from a family of open strips R×(0,1)\mathbb{R}\times(0,1) with boundary intervals by gluing those strips along their boundary intervals. Every such strip has a foliation into parallel lines R×t\mathbb{R}\times t, t(0,1)t\in(0,1), and boundary intervals, whence we get a foliation Δ\Delta on all of ZZ. Many types of foliations on surfaces with leaves homeomorphic to the real line have such "striped" structure. That fact was discovered by W. Kaplan (1940-41) for foliations on the plane R2\mathbb{R}^2 by level-set of pseudo-harmonic functions R2R\mathbb{R}^2 \to \mathbb{R} without singularities. Previously, the first two authors studied the homotopy type of the group H(Δ)\mathcal{H}(\Delta) of homeomorphisms of ZZ sending leaves of Δ\Delta onto leaves, and shown that except for two cases the identity path component H0(Δ)\mathcal{H}_{0}(\Delta) of H(Δ)\mathcal{H}(\Delta) is contractible. The aim of the present paper is to show that the quotient H(Δ)/H0(Δ)\mathcal{H}(\Delta)/ \mathcal{H}_{0}(\Delta) can be identified with the group of automorphisms of a certain graph with additional structure encoding the "combinatorics" of gluing.

Keywords

Cite

@article{arxiv.1708.00216,
  title  = {Homeotopy groups of one-dimensional foliations on surfaces},
  author = {Sergiy Maksymenko and Eugene Polulyakh and Yuliya Soroka},
  journal= {arXiv preprint arXiv:1708.00216},
  year   = {2017}
}

Comments

21 pages, 7 figures