English

$K_n$-free Character Graphs with at Least $2n$ Vertices

Group Theory 2020-02-18 v2

Abstract

For a finite group GG, let Δ(G)\Delta(G) denote the character graph built on the set of degrees of the irreducible complex characters of GG. Akhlaghi and Tong-Viet in \cite{[AT]} conjectured that if for some positive integer nn, Δ(G)\Delta(G) is KnK_n-free, then Δ(G)\Delta(G) has at most 2n12n-1 vertices. In this paper, we present an example to show that this conjecture is not necessarily true for all non-solvable groups whose character graphs are KnK_n-free.

Keywords

Cite

@article{arxiv.2002.03852,
  title  = {$K_n$-free Character Graphs with at Least $2n$ Vertices},
  author = {Mahdi Ebrahimi},
  journal= {arXiv preprint arXiv:2002.03852},
  year   = {2020}
}

Comments

arXiv admin note: text overlap with arXiv:2002.01353. The counterexample given in this manuscripts has been presented in [Bounding the number of vertices in the degree graph of a finite group, Z. Akhlaghi, S. Dolfi, E. Pacifici, L. Sanus, Journal of Pure and Applied Algebra, 224(2020) 725-731

R2 v1 2026-06-23T13:36:57.438Z