English

Whitney's Theorem for Line Graphs of Multi-Graphs

Combinatorics 2021-05-19 v1

Abstract

Whitney's Theorem states that every graph, different from K3K_3 or K1,3K_{1,3}, is uniquely determined by its line graph. A 11-line graph of a multi-graph is the graph with as vertices the edges of the multi-graph, and two edges adjacent if and only if there is a unique vertex on both edges. The 1\geq 1-line graph of a multi-graph is the graph on the edges of the multi-graph, where two edges are adjacent if and only if there is at least one vertex on both edges. We extend Whitney's theorem to such line graphs of multi-graphs, and show that most multi-graphs are uniquely determined by their line graph. Moreover, we present an algorithm to determine for a given graph Γ\Gamma, if possible, a multi-graph with Γ\Gamma as line graph.

Keywords

Cite

@article{arxiv.2105.08610,
  title  = {Whitney's Theorem for Line Graphs of Multi-Graphs},
  author = {Hans Cuypers},
  journal= {arXiv preprint arXiv:2105.08610},
  year   = {2021}
}
R2 v1 2026-06-24T02:13:48.605Z