English
Related papers

Related papers: Square character degree graphs yield direct produc…

200 papers

Let $G$ be a finite group and $\chi$ be an irreducible character of $G$. The codegree of $\chi$ is defined as $\chi^c(1) =\frac{|G: \ker\chi|}{\chi(1)}$. In a paper by Gao, Wang, and Chen, it was shown that $G$ cannot satisfy the condition…

Group Theory · Mathematics 2025-07-16 Karam Aldahleh , Alan Kappler , Neil Makur , Yong Yang

Let $G$ be a finite group, and let $d$ be the degree of an irreducible character of $G$ such that $|G|=d(d+e)$ for some $e>1$. Consider the case when $G$ is solvable, $d$ is square-free, and $(d,d+e)=1$. We wish to explore an equivalent…

Group Theory · Mathematics 2024-11-14 Mark L. Lewis , Brandon Martin

The codegree of an irreducible character $\chi$ of a finite group $G$ is defined as $|G:\ker\chi|/\chi(1)$. The codegree graph $\Gamma(G)$ of a finite group $G$ is the graph whose vertices are the prime divisors of $|G|$, where two distinct…

Group Theory · Mathematics 2025-10-20 Jiyong Chen , Ni Du , Leyi Li

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

For a finite group $G$, let $\Delta(G)$ denote the character graph built on the set of degrees of the irreducible complex characters of $G$. In this paper, we determine the structure of all finite groups $G$ with $K_4$-free character graph…

Group Theory · Mathematics 2019-09-04 Mahdi Ebrahimi

Let $G$ be a finite group and let $\rm{Irr}(G)$ be the set of all irreducible complex characters of $G$. Let $\rm{cd}(G)$ be the set of all character degrees of $G$ and denote by $\rho(G)$ the set of primes which divide some character…

Group Theory · Mathematics 2020-06-30 Mahdi Ebrahimi

We obtain a necessary condition for the character degree graph of a solvable group G to be Eulerian.

Group Theory · Mathematics 2023-05-23 G Sivanesan , C Selvaraj , T Tamizh Chelvam

Let \(G\) be a finite solvable group, and let \(\Delta(G)\) denote the \emph{prime graph} built on the set of degrees of the irreducible complex characters of \(G\). A fundamental result by P.P. P\'alfy asserts that the complement…

Group Theory · Mathematics 2017-06-15 Zeinab Akhlaghi , Carlo Casolo , Silvio Dolfi , Khatoon Khedri , Emanuele Pacifici

We study here the graphs with seven vertices in an effort to classify which of them appear as the prime character degree graphs of finite solvable groups. This classification is complete for the disconnected graphs. Of the 853…

Group Theory · Mathematics 2023-08-03 Jacob Laubacher , Mark Medwid , Dylan Schuster

For a finite group $G$, let $\Delta(G)$ denote the character graph built on the set of degrees of the irreducible complex characters of $G$. Akhlaghi and Tong-Viet in \cite{[AT]} conjectured that if for some positive integer $n$,…

Group Theory · Mathematics 2020-02-18 Mahdi Ebrahimi

Let $G$ be a finite group. Define a graph on the set $G^{\#} = G \setminus \{ 1 \}$ by declaring distinct elements $x,y\in G^{\#}$ to be adjacent if and only if $\langle x,y\rangle$ is cyclic. Denote this graph by $\Delta(G)$. The graph…

Group Theory · Mathematics 2021-03-10 David G. Costanzo , Mark L. Lewis , Stefano Schmidt , Eyob Tsegaye , Gabe Udell

Equivalence relations on the edge set of a graph $G$ that satisfy restrictive conditions on chordless squares play a crucial role in the theory of Cartesian graph products and graph bundles. We show here that such relations in a natural way…

Discrete Mathematics · Computer Science 2014-07-14 Marc Hellmuth , Lydia Ostermeier , Peter F. Stadler

A {\it graph product} $G$ on a graph $\Gamma$ is a group defined as follows: For each vertex $v$ of $\Gamma$ there is a corresponding non-trivial group $G_v$. The group $G$ is the quotient of the free product of the $G_v$ by the commutation…

Group Theory · Mathematics 2020-04-24 Michael Mihalik

The spectrum $\omega(G)$ of a finite group $G$ is the set of orders of its elements. The following sufficient criterion of nonsolvability is proved: if among the prime divisors of the order of a group $G$, there are four different primes…

Group Theory · Mathematics 2023-04-25 Zh. Wang , A. V. Vasil'ev , M. A. Grechkoseeva , A. Kh. Zhurtov

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. We consider the set of the irreducible complex characters of $G$, namely $Irr(G)$, and the related degree set $cd(G)=\{\chi(1) : \chi\in Irr(G)\}$. Let $\rho(G)$ be the set of all primes which divide some…

Group Theory · Mathematics 2015-11-25 Roghayeh Hafezieh

A \textit{$k$-total coloring} of a graph $G$ is an assignment of $k$ colors to its elements (vertices and edges) so that adjacent or incident elements have different colors. The total chromatic number is the smallest integer $k$ for which…

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 and only if there is an element of order $pq$ in $G$. Prime graphs of solvable…

Group Theory · Mathematics 2024-07-10 Thomas Michael Keller , Gavin Pettigrew , Saskia Solotko , Lixin Zheng

Let $G$ be a finite group, and let ${\rm{cd}}(G)$ denote the set of degrees of the irreducible complex characters of $G$. The degree graph $\Delta(G)$ of $G$ is defined as the simple undirected graph whose vertex set ${\rm{V}}(G)$ consists…

Group Theory · Mathematics 2018-11-06 Zeinab Akhlaghi , Silvio Dolfi , Emanuele Pacifici , Lucia Sanus

Let $G$ be a finite group and ${\rm cd}(G)$ will be the set of the degrees of the complex irreducible characters of $G$. Also let ${\rm cod}(G)$ be the set of codegrees of the irreducible characters of $G$. The Taketa problem conjectures if…

Group Theory · Mathematics 2021-07-06 Mahtab Delfani , Mohsen Ghasemi , Somayeh Hekmatara