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Let $G$ be a finite group and construct a graph $\Delta(G)$ by taking $G\setminus\{1\}$ as the vertex set of $\Delta(G)$ and by drawing an edge between two vertices $x$ and $y$ if $\langle x,y\rangle$ is cyclic. Let $K(G)$ be the set…

Group Theory · Mathematics 2024-02-12 David G. Costanzo , Mark L. Lewis , Stefano Schmidt , Eyob Tsegaye , Gabe Udell

This paper studies intersections of principal blocks of a finite group with respect to different primes. We first define the block graph of a finite group $G$, whose vertices are the prime divisors of $|G|$ and there is an edge between two…

Representation Theory · Mathematics 2017-07-20 Julian Brough , Yanjun Liu , Alessandro Paolini

The power graph of a group $G$ is a simple and undirected graph with vertex set $G$ and two distinct vertices are adjacent if one is a power of the other. In this article, we characterize (non-cyclic) finite groups of prime exponent and…

Combinatorics · Mathematics 2019-03-20 Ramesh Prasad Panda

Let $G$ be a finite insoluble group with soluble radical $ R(G)$. The solubility graph $\Gamma_{\rm S}(G)$ of $G$ is a simple graph whose vertices are the elements of $G\setminus R(G) $ and two distinct vertices $x$ and $y$ are adjacent if…

Group Theory · Mathematics 2023-05-29 Mina Poozesh , Yousef Zamani

Let $G$ be a finite group and $\mathrm{Irr}(G)$ be the set of all complex irreducible characters of $G$. The character-graph $\Delta(G)$ associated to $G$, is a graph whose vertex set is the set of primes which divide the degrees of some…

Group Theory · Mathematics 2021-09-27 Mahdi Ebrahimi , Maryam Khatami , Zohreh Mirzaei

Let $G$ be a finite group and let $\rm{Irr}(G)$ be the set of all irreducible complex characters of $G$. For a character $\chi \in \rm{Irr}(G)$, the number $\rm{cod}(\chi):=|G:\rm{ker}\chi|/\chi(1)$ is called the co-degree of $\chi$. The…

Group Theory · Mathematics 2020-08-07 Mahdi Ebrahimi

For a finite non-abelian group $G$ let $\rat(G)$ denote the largest ratio of degrees of two nonlinear irreducible characters of $G$. We prove that the number of non-abelian composition factors of $G$ is bounded above by…

Group Theory · Mathematics 2015-02-26 Mark L. Lewis , Hung Ngoc Nguyen

We introduce and investigate the solvable graph $\Gamma_\mathfrak{S}(L)$ of a finite-dimensional Lie algebra $L$ over a field $F$. The vertices are the elements outside the solvabilizer $\sol(L)$, and two vertices are adjacent whenever they…

Rings and Algebras · Mathematics 2025-11-12 David Towers , Ismael Gutierrez , Luis Fernandez

Let $G$ be a group and $Sol(G)=\{x \in G : \langle x,y \rangle \text{ is solvable for all } y \in G\}$. We associate a graph $\mathcal{NS}_G$ (called the non-solvable graph of $G$) with $G$ whose vertex set is $G \setminus Sol(G)$ and two…

Group Theory · Mathematics 2019-09-27 Parthajit Bhowal , Deiborlang Nongsiang , Rajat Kanti Nath

Let $G$ be a finite group. The solubility graph associated with the finite group $G$, denoted by $\Gamma_{\cal S}(G)$, is a simple graph whose vertices are the non-trivial elements of $G$, and there is an edge between two distinct elements…

Group Theory · Mathematics 2020-03-04 B. Akbari , Mark L. Lewis , J. Mirzajani , A. R. Moghaddamfar

For a finite group $G$, the vertices of the prime graph $\Gamma(G)$ are the primes that divide $|G|$, and two vertices $p$ and $q$ are connected by an edge if there is an element of order $pq$ in $G$. Prime graphs of solvable groups have…

Group Theory · Mathematics 2024-10-29 Thomas Michael Keller , Zachary Martin , Alexa Renner , Gabriel Roca , Eric Yu

The Gruenberg-Kegel graph of a group is the undirected graph whose vertices are those primes which occur as the order of an element of the group, and distinct vertices $p$, $q$ are joined by an edge whenever the group has an element of…

Group Theory · Mathematics 2026-04-07 Andreas Bächle , Ann Kiefer , Sugandha Maheshwary , Ángel del Río

In this paper we introduce the graph $\Gamma_{sc}(G)$ associated with a group $G$, called the solvable conjugacy class graph (abbreviated as SCC-graph), whose vertices are the nontrivial conjugacy classes of $G$ and two distinct conjugacy…

Combinatorics · Mathematics 2022-02-08 Parthajit Bhowal , Peter J. Cameron , Rajat Kanti Nath , Benjamin Sambale

The Gruenberg-Kegel graph $\Gamma(G)$ associated with a finite group $G$ has as vertices the prime divisors of $|G|$, with an edge from $p$ to $q$ if and only if $G$ contains an element of order $pq$. This graph has been the subject of much…

Group Theory · Mathematics 2023-02-01 Peter J. Cameron , Natalia V. Maslova

We investigate character degree graphs of solvable groups. In particular, we provide general results that can be used to eliminate which degree graphs can occur as solvable groups. Finally, we show a specific family of graphs cannot occur…

Representation Theory · Mathematics 2024-02-28 Mark W. Bissler , Jacob Laubacher , Mark L. Lewis

A finite group $G$ is said to be rational if every character of $G$ is rational-valued. The Gruenberg-Kegel graph of a finite group $G$ is the undirected graph whose vertices are the primes dividing the order of $G$ and the edges join…

Group Theory · Mathematics 2024-04-02 Sara C. Debón , Diego García-Lucas , Ángel del Río

Let $G$ be a finite group and ${\rm cd}(G)$ denote the set of complex irreducible character degrees of $G$. In this paper, we prove that if $G$ is a finite group and $H$ is an almost simple group with socle $H_{0}= \, ^{2}{\rm G}_{2}(q)$,…

Group Theory · Mathematics 2023-03-08 Seyed Hassan Alavi

The prime graph of a finite group $G$, which is denoted by ${\rm GK}(G)$, is a simple graph whose vertex set is comprised of the prime divisors of $|G|$ and two distinct prime divisors $p$ and $q$ are joined by an edge if and only if there…

Group Theory · Mathematics 2015-02-19 B Akbari , A. R. Moghaddamfar

Let $G$ be a finite group. Denote by $\textrm{Irr}(G)$ the set of all irreducible complex characters of $G.$ Let $\textrm{cd}(G)=\{\chi(1)\;|\;\chi\in \textrm{Irr}(G)\}$ be the set of all irreducible complex character degrees of $G$…

Group Theory · Mathematics 2011-02-23 Hung P. Tong-Viet

Let $\Gamma(G)$ be the Gruenberg-Kegel graph of a finite group $G$. We prove that if $G$ is solvable and $\sigma$ is a cut-set for $\Gamma(G)$, then $G$ has a $\sigma$-series of length $5$ whose factors are controlled. As a consequence, we…

Group Theory · Mathematics 2025-04-29 Lorenzo Bonazzi