English

Intersection subgroup graph with forbidden subgraphs

Combinatorics 2023-08-23 v1

Abstract

Let GG be a group. The intersection subgroup graph of GG (introduced by Anderson et al. \cite{anderson}) is the simple graph ΓS(G)\Gamma_{S}(G) whose vertices are those non-trivial subgroups say HH of GG with HK={e}H\cap K=\{e\} for some non-trivial subgroup KK of GG; two distinct vertices HH and KK are adjacent if and only if HK={e}H\cap K=\{e\}, where ee is the identity element of GG. In this communication, we explore the groups whose intersection subgroup graph belongs to several significant graph classes including cluster graphs, perfect graphs, cographs, chordal graphs, bipartite graphs, triangle-free and claw-fee graphs. We categorize each nilpotent group GG so that ΓS(G)\Gamma_S(G) belongs to the above classes. We entirely classify the simple group of Lie type whose intersection subgroup graph is a cograph. Moreover, we deduce that ΓS(G)\Gamma_{S}(G) is neither a cograph nor a chordal graph if GG is a torsion-free nilpotent group.

Keywords

Cite

@article{arxiv.2308.11301,
  title  = {Intersection subgroup graph with forbidden subgraphs},
  author = {Santanu Mandal and Pallabi Manna},
  journal= {arXiv preprint arXiv:2308.11301},
  year   = {2023}
}
R2 v1 2026-06-28T12:01:17.115Z