English

Counting fixed points free vector fields on $\mathbb{B}^{2}$

Geometric Topology 2018-07-11 v1 Combinatorics

Abstract

The number of diagrams of stationary points free vector fields in the 2-disk B2\mathbb{B}^{2} is counted in the article. It is shown that the number of such diagrams with 2k2k exceptional points on the boundary S1\mathbb{S}^{1} equals 3k2(Ck+2Ck1)3^{k-2}(C_{k}+2C_{k-1}), where CkC_{k} is the corresponding Catalan number. An algorithm for finding all such diagrams is discussed.

Cite

@article{arxiv.1807.03714,
  title  = {Counting fixed points free vector fields on $\mathbb{B}^{2}$},
  author = {Simeon T. Stefanov},
  journal= {arXiv preprint arXiv:1807.03714},
  year   = {2018}
}

Comments

14 pages, 11 figures

R2 v1 2026-06-23T02:56:35.848Z