English

Generalizing Cographs to 2-Cographs

Combinatorics 2022-03-11 v2

Abstract

A graph in which every connected induced subgraph has a disconnected complement is called a cograph. Such graphs are precisely the graphs that do not have the 4-vertex path as an induced subgraph. We define a 22-cograph to be a graph in which the complement of every 22-connected induced subgraph is not 22-connected. We show that, like cographs, 22-cographs can be recursively defined. But, unlike cographs, 22-cographs are closed under induced minors. We characterize the class of non-22-cographs for which every proper induced minor is a 22-cograph. We further find the finitely many members of this class whose complements are also induced-minor-minimal non-22-cographs.

Keywords

Cite

@article{arxiv.2103.00403,
  title  = {Generalizing Cographs to 2-Cographs},
  author = {James Oxley and Jagdeep Singh},
  journal= {arXiv preprint arXiv:2103.00403},
  year   = {2022}
}

Comments

32 pages

R2 v1 2026-06-23T23:34:47.316Z