English

Two New Characterizations of Path Graphs

Combinatorics 2022-08-02 v1 Discrete Mathematics

Abstract

Path graphs are intersection graphs of paths in a tree. We start from the characterization of path graphs by Monma and Wei [C.L.~Monma,~and~V.K.~Wei, Intersection Graphs of Paths in a Tree, J. Combin. Theory Ser. B, 41:2 (1986) 141--181] and we reduce it to some 2-colorings subproblems, obtaining the first characterization that directly leads to a polynomial recognition algorithm. Then we introduce the collection of the attachedness graphs of a graph and we exhibit a list of minimal forbidden 2-edge colored subgraphs in each of the attachedness graph.

Keywords

Cite

@article{arxiv.2208.01001,
  title  = {Two New Characterizations of Path Graphs},
  author = {Nicola Apollonio and Lorenzo Balzotti},
  journal= {arXiv preprint arXiv:2208.01001},
  year   = {2022}
}

Comments

18 pages, 6 figures

R2 v1 2026-06-25T01:23:23.057Z