{ "id": "1909.07964", "version": "v1", "published": "2019-09-17T17:53:41.000Z", "updated": "2019-09-17T17:53:41.000Z", "title": "On clique immersions in line graphs", "authors": [ "Michael Guyer", "Jessica McDonald" ], "comment": "10 pages, 4 figures", "categories": [ "math.CO" ], "abstract": "We prove that if $L(G)$ immerses $K_t$ then $L(mG)$ immerses $K_{mt}$, where $mG$ is the graph obtained from $G$ by replacing each edge in $G$ with a parallel edge of multiplicity $m$. This implies that when $G$ is a simple graph, $L(mG)$ satisfies a conjecture of Abu-Khzam and Langston. We also show that when $G$ is a line graph, $G$ has a $K_t$-immersion iff $G$ has a $K_t$-minor whenever $t\\leq 4$, but this equivalence fails in both directions when $t=5$.", "revisions": [ { "version": "v1", "updated": "2019-09-17T17:53:41.000Z" } ], "analyses": { "keywords": [ "line graph", "clique immersions", "equivalence fails", "parallel edge", "simple graph" ], "note": { "typesetting": "TeX", "pages": 10, "language": "en", "license": "arXiv", "status": "editable" } } }