English

Strong coloring 2-regular graphs: Cycle restrictions and partial colorings

Combinatorics 2021-07-08 v2 Discrete Mathematics

Abstract

Let HH be a graph with Δ(H)2\Delta(H) \leq 2, and let GG be obtained from HH by gluing in vertex-disjoint copies of K4K_4. We prove that if HH contains at most one odd cycle of length exceeding 33, or if HH contains at most 33 triangles, then χ(G)4\chi(G) \leq 4. This proves the Strong Coloring Conjecture for such graphs HH. For graphs HH with Δ=2\Delta=2 that are not covered by our theorem, we prove an approximation result towards the conjecture.

Keywords

Cite

@article{arxiv.2001.05051,
  title  = {Strong coloring 2-regular graphs: Cycle restrictions and partial colorings},
  author = {Jessica McDonald and Gregory J. Puleo},
  journal= {arXiv preprint arXiv:2001.05051},
  year   = {2021}
}

Comments

17 pages, 2 figures

R2 v1 2026-06-23T13:11:24.143Z