English

Every subcubic multigraph is $(1,2^7)$-packing edge-colorable

Combinatorics 2022-07-01 v1

Abstract

For a non-decreasing sequence S=(s1,,sk)S = (s_1, \ldots, s_k) of positive integers, an SS-packing edge-coloring of a graph GG is a decomposition of edges of GG into disjoint sets E1,,EkE_1, \ldots, E_k such that for each 1ik1 \le i \le k the distance between any two distinct edges e1,e2Eie_1, e_2 \in E_i is at least si+1s_i+1. The notion of SS-packing edge-coloring was first generalized by Gastineau and Togni from its vertex counterpart. They showed that there are subcubic graphs that are not (1,2,2,2,2,2,2)(1,2,2,2,2,2,2)-packing (abbreviated to (1,26)(1,2^6)-packing) edge-colorable and asked the question whether every subcubic graph is (1,27)(1,2^7)-packing edge-colorable. Very recently, Hocquard, Lajou, and Lu\v{z}ar showed that every subcubic graph is (1,28)(1,2^8)-packing edge-colorable and every 33-edge colorable subcubic graph is (1,27)(1,2^7)-packing edge-colorable. Furthermore, they also conjectured that every subcubic graph is (1,27)(1,2^7)-packing edge-colorable. In this paper, we confirm the conjecture of Hocquard, Lajou, and Lu\v{z}ar, and extend it to multigraphs.

Keywords

Cite

@article{arxiv.2206.15046,
  title  = {Every subcubic multigraph is $(1,2^7)$-packing edge-colorable},
  author = {Xujun Liu and Michael Santana and Taylor Short},
  journal= {arXiv preprint arXiv:2206.15046},
  year   = {2022}
}

Comments

24 pages, 4 figures

R2 v1 2026-06-24T12:09:12.494Z