English

On clique immersions in line graphs

Combinatorics 2020-05-19 v2

Abstract

We prove that if L(G)L(G) immerses KtK_t then L(mG)L(mG) immerses KmtK_{mt}, where mGmG is the graph obtained from GG by replacing each edge in GG with a parallel edge of multiplicity mm. This implies that when GG is a simple graph, L(mG)L(mG) satisfies a conjecture of Abu-Khzam and Langston. We also show that when GG is a line graph, GG has a KtK_t-immersion iff GG has a KtK_t-minor whenever t4t\leq 4, but this equivalence fails in both directions when t5t \geq 5.

Keywords

Cite

@article{arxiv.1909.07964,
  title  = {On clique immersions in line graphs},
  author = {Michael Guyer and Jessica McDonald},
  journal= {arXiv preprint arXiv:1909.07964},
  year   = {2020}
}

Comments

11 pages, 5 figures

R2 v1 2026-06-23T11:18:15.042Z