2019/09/19 by Roghayeh HAFEZİEH, Mohammad Ali Hosseinzadeh, Hafezieh, Roghayeh +5
Computer Science · Mathematics · #20C15 #Coding theory and cryptography #Combinatorics (math.CO) #FOS: Mathematics #Finite Group Theory Research #Graph theory and applications #Group Theory (math.GR)
paper · pdf · doi:10.48550/arxiv.1909.09236
openalex publication_date 2019/09/19 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Given a finite group G, the character graph, denoted by Δ(G), for its irreducible character degrees is a graph with vertex set ρ(G) which is the set of prime numbers that divide the irreducible character degrees of G, and with \p,q\ being an edge if there exist a non-linear χ∈ \rm Irr(G) whose degree is divisible by pq. In this paper, we discuss the influences of cut vertices and eigenvalues of Δ(G) on the group structure of G. Recently, Lewis and Meng proved the character graph of each solvable group has at most one cut vertex. Now, we determine the structure of character graphs of solvable groups with a cut vertex and diameter 3. Furthermore, we study solvable groups whose character graphs have at most two distinct eigenvalues. Moreover, we investigate the solvable groups whose character graphs are regular with three distinct eigenvalues. In addition, we give some lower bounds for the number of edges of Δ(G).