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A set $X \subseteq V(G)$ in a graph $G$ is $(q,k)$-unbreakable if every separation $(A,B)$ of order at most $k$ in $G$ satisfies $|A \cap X| \leq q$ or $|B \cap X| \leq q$. In this paper, we prove the following result: If a graph $G$…

Combinatorics · Mathematics 2022-10-27 Daniel Lokshtanov , Marcin Pilipczuk , Michał Pilipczuk , Saket Saurabh

For each positive integer $n$, we define the divisibility relation graph $D_n$ whose vertex set is the set of divisors of $n$, and in which two vertices are adjacent if one is a divisor of the other. This type of graph is a special case of…

Combinatorics · Mathematics 2025-07-10 Jonathan L. Merzel , Ján Mináč , Tung T. Nguyen , Nguyen Duy Tân

For a character $\chi$ of a finite group $G$, the number cod$(\chi):=|G:\mathrm{ker}(\chi)|/\chi(1)$ is called the codegree of $\chi$.In this paper, we give a solvability criterion for a finite group $G$ depending on the minimum of the…

Group Theory · Mathematics 2022-08-17 Dongfang Yang , Yu Zeng , Heng Lv

In this communication, the co-maximal subgroup graph $\Gamma(G)$ of a finite group $G$ is examined when $G$ is a finite nilpotent group, finite abelian group, dihedral group $D_n$, dicyclic group $Q_{2^n}$, and $p$-group. We derive the…

Combinatorics · Mathematics 2023-10-11 Pallabi Manna , Santanu Mandal , Manideepa Saha

Given a 2-generated finite group $G$, the non-generating graph of $G$ has as vertices the elements of $G$ and two vertices are adjacent if and only if they are distinct and do not generate $G$. We consider the graph $\Sigma(G)$ obtained…

Group Theory · Mathematics 2021-08-31 Andrea Lucchini , Daniele Nemmi

We are interested in determining the bound of the average of the degrees of the irreducible characters whose degrees are not divisible by some prime $p$ that guarantees a finite group $G$ of odd order is $p$-nilpotent. We find a bound that…

Group Theory · Mathematics 2022-03-25 Ramadan Elsharif , Mark L. Lewis

We introduce the notion of finite stature of a family $\{H_i\}$ of subgroups of a group $G$. We investigate the separability of subgroups of a group $G$ that splits as a graph of hyperbolic special groups with quasiconvex edge groups. We…

Group Theory · Mathematics 2019-04-15 Jingyin Huang , Daniel T. Wise

If $G$ be a finite $p$-group and $\chi$ is a non-linear irreducible character of $G$, then $\chi(1)\leq |G/Z(G)|^{\frac{1}{2}}$. In \cite{fernandez2001groups}, Fern\'{a}ndez-Alcober and Moret\'{o} obtained the relation between the character…

Group Theory · Mathematics 2024-03-25 Nabajit Talukdar , Kukil Kalpa Rajkhowa

Let F be a finite field with q elements, let A be a finite dimensional F-algebra and let J=J(A) be the Jacobson radical of A. Then G=1+J is a p-group, where p is the characteristic of F. We refer to G as an F-algebra group. A subgroup H of…

Representation Theory · Mathematics 2007-05-23 Carlos A. M. Andre

Given a finite, simple graph $G$, the $k$-component order edge connectivity of $G$ is the minimum number of edges whose removal results in a subgraph for which every component has order at most $k-1$. In general, determining the…

Combinatorics · Mathematics 2023-10-10 Michael Yatauro

The power graph of a group $G$ is the graph whose vertex set is $G$ and two distinct vertices are adjacent if one is a power of the other. This paper investigates the minimal separating sets of power graphs of finite groups. For power…

Combinatorics · Mathematics 2017-03-28 Ramesh Prasad Panda , K. V. Krishna

Many degree sequences can only be realised in graphs that contain a `ds-completable card', defined as a vertex-deleted subgraph in which the erstwhile neighbours of the deleted vertex can be identified from their degrees, if one knows the…

Combinatorics · Mathematics 2018-10-08 Andrew M. Steane

We investigate the finite groups $G$ for which $\chi(1)^{2}=|G:Z(\chi)|$ for all characters $\chi \in Irr(G)$ and $|cd(G)|=2$, where $cd(G)=\{\chi(1)| \chi \in Irr(G)\}$. We call such a group a GVZ-group with two character degrees. We…

Group Theory · Mathematics 2024-07-16 Nabajit Talukdar , Kukil Kalpa Rajkhowa

For a given graph whose edges are labeled with general real numbers, we consider the set of functions from the vertex set into the Euclidean plane such that the distance between the images of neighbouring vertices is equal to the…

Combinatorics · Mathematics 2025-07-23 Niels Lubbes , Mehdi Makhul , Josef Schicho , Audie Warren

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

The power graph of a finite group $G$ is a simple undirected graph with vertex set $G$ and two vertices are adjacent if one is a power of the other. The enhanced power graph of a finite group $G$ is a simple undirected graph whose vertex…

Group Theory · Mathematics 2023-01-03 Parveen , Jitender Kumar , Ramesh Prasad Panda

Absolutely indecomposable vector bundle and parabolic vector bundles are well-studied via quiver representations. In this paper, we study absolutely indecomposable quasi-parabolic $G$-bundles over $\mathbb{P}^1$ with generic additive…

Algebraic Geometry · Mathematics 2026-05-27 GyeongHyeon Nam

Let $ G $ be a finite group and $ \chi \in \mathrm{Irr}(G) $. Define $ \mathrm{cv}(G)=\{\chi(g)\mid \chi \in \mathrm{Irr}(G), g\in G \} $, $ \mathrm{cv}(\chi)=\{\chi(g)\mid g\in G \} $ and denote $ \mathrm{dl}(G) $ by the derived length of…

Group Theory · Mathematics 2025-04-01 Sesuai Y. Madanha , X. Mbaale , Tendai M. Mudziiri Shumba

Let $\Gamma$ be a finite simple graph. If for some integer $n\geqslant 4$, $\Gamma$ is a $K_n$-free graph whose complement has an odd cycle of length at least $2n-5$, then we say that $\Gamma$ is an $n$-exact graph. For a finite group $G$,…

Group Theory · Mathematics 2020-02-05 Mahdi Ebrahimi

We study the undirected divisibility graph in which the vertex set is a finite subset of consecutive natural numbers up to N.We derive analytical expressions for measures of the graph like degree, clustering, geodesic distance and…

Combinatorics · Mathematics 2020-10-26 R. Abiya , G. Ambika