English

A spatial version of Tutte's conflict graph

Combinatorics 2023-02-28 v3 Geometric Topology

Abstract

Tutte showed that a graph GG is planar if and only if the conflict graph associated to every cycle of GG is bipartite. We define a (not necessarily unique) signed conflict graph associated to a maximally planar subgraph of a nonplanar graph such that if GG has a flat embedding, every possible conflict graph associated to every maximally planar subgraph of GG is balanced. In doing this, we show that for every graph GG with flat embedding, and a planar subgraph PP of GG, PP lies on a sphere that intersects GG only in PP. We conjecture that GG is intrinsically linked if and only if every maximal planar subgraph of GG has every possible conflict graph unbalanced.

Keywords

Cite

@article{arxiv.2207.06244,
  title  = {A spatial version of Tutte's conflict graph},
  author = {Joel Foisy},
  journal= {arXiv preprint arXiv:2207.06244},
  year   = {2023}
}
R2 v1 2026-06-25T00:53:00.783Z