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We obtain the codegree of a certain primitive character for a finite solvable group, and thereby give a negative answer to a question proposed by Moret\'o in \cite{Moreto}.

Group Theory · Mathematics 2021-11-02 Ping Jin , Lei Wang , Yong Yang

We determine the number of isomorphism classes of elementary gradings by a finite group on an algebra of upper block-triangular matrices. As a consequence we prove that, for a finite abelian group $G$, the sequence of the numbers $E(G,m)$…

Rings and Algebras · Mathematics 2020-04-07 Diogo Diniz , Daniel Pellegrino

Let $S_n$ and $A_n$ denote the symmetric group and alternating group of degree $n$ with $n\geq 3$, respectively. Let $S$ be the set of all $3$-cycles in $S_n$. The \emph{complete alternating group graph}, denoted by $CAG_n$, is defined as…

Combinatorics · Mathematics 2017-08-29 Xueyi Huang , Qiongxiang Huang

Let G be a group and H a subgroup of G of finite index. In this article, it is proved that if the number of isomorphism classes of right transversals of H in G is 5, then the index of H in G is 6 and the permutation representation of G on…

Group Theory · Mathematics 2024-01-09 Vivek Kumar Jain , Raja Rawat

M.R.Jones and J.Wiegold in [3] have shown that if $G$ is a finite group with a subgroup $H$ of finite index $n$, then the $n$-th power of Schur multiplier of $G$, $M(G)^n$, is isomorphic to a subgroup of $M(H)$. In this paper we prove a…

Group Theory · Mathematics 2011-04-05 Mohammad Reza Rajabzadeh Moghaddam , Behrooz Mashayekhy , Saeed Kayvanfar

Unigraphs are graphs identifiable up to isomorphism from their degree sequences. Given a class $\mathcal{A}$ of graphs, we define the class of $\mathcal{A}$-unigraphs to be graphs identifiable from degree sequence and membership in…

Combinatorics · Mathematics 2024-06-07 R. Whitman

An ordinary character $\chi $ of a finite group is called orthogonally stable, if all non-degenerate invariant quadratic forms on any module affording the character $\chi $ have the same discriminant. This is the orthogonal discriminant,…

Representation Theory · Mathematics 2022-06-01 Gabriele Nebe

Let $\Gamma(G)$ be the prime graph associated with a finite group $G$ and $D(G)$ be the degree pattern of $G$. A finite group $G$ is said to be $k$-fold OD-characterizable if there exist exactly $k$ non-isomorphic groups $H$ such that…

Group Theory · Mathematics 2017-05-26 Ali Reza Moghaddamfar

Let $G$ be a finite group. Suppose $N$ is a normal subgroup of $G$. Recall that Gallagher's theorem states that if $\chi \in {\rm Irr} (G)$ satisfies $\chi_N$ is irreducible, then $\chi \beta$ is irreducible and distinct for all $\beta \in…

Group Theory · Mathematics 2025-11-11 Xiaoyou Chen , Mark L. Lewis

We study gradings by noncommutative groups on finite dimensional Lie algebras over an algebraically closed field of characteristic zero. It is shown that if $L$ is gradeg by a non-abelian finite group $G$ then the solvable radical $R$ of…

Rings and Algebras · Mathematics 2016-02-19 Dušan Pagon , Dušan Repovš , Mikhail Zaicev

If V is a representation of a linear algebraic group G, a set S of G-invariant regular functions on V is called separating if the following holds: If two elements v,v' from V can be separated by an invariant function, then there is an f…

Commutative Algebra · Mathematics 2014-06-25 Martin Kohls , Hanspeter Kraft

A finite group $G$ is $normally ~monomial$ if all its irreducible characters are induced from linear characters of normal subgroups of $G$. In this paper, we determine all possible irreducible character degree sets of normally monomial…

Group Theory · Mathematics 2022-09-13 Dongfang Yang , Heng Lv

Let $q$ be a prime power and $U$ the group of lower unitriangular matrices of order $n$ for some natural number $n$. We give a lower bound for the degrees of irreducible constituents of Andr\'{e}-Yan supercharacters and classify the…

Representation Theory · Mathematics 2013-12-13 Richard Dipper , Qiong Guo

We establish new bounds on character values and character ratios for finite groups $G$ of Lie type, which are considerably stronger than previously known bounds, and which are best possible in many cases. These bounds have the form…

Group Theory · Mathematics 2017-07-14 Roman Bezrukavnikov , Martin W. Liebeck , Aner Shalev , Pham Huu Tiep

Suppose that $\chi$ is an irreducible complex character of $G$ and let $f_\chi$ be the smallest integer $n$ such that the cyclotomic field $\mathbb Q_n$ contains the values of $\chi$. Let $p$ be a prime, and assume that $\chi \in…

Group Theory · Mathematics 2016-01-14 Carolina Vallejo Rodríguez

Let $G$ be a finite group, let $N$ be a normal subgroup of $G$ and let $\theta$ be an irreducible character of $N$. We count the real irreducible characters of $G$ lying over $\theta$

Group Theory · Mathematics 2023-01-04 John C. Murray

The spectrum of a finite group is the set of its elements orders. Groups are said to be isospectral if their spectra coincide. For every finite simple exceptional group $L=E_7(q)$, we prove that each finite group isospectral to $L$ is…

Group Theory · Mathematics 2021-01-01 Andrey V. Vasil'ev , Alexey M. Staroletov

An irreducible character of a finite group $G$ is called quasi $p$-Steinberg character for a prime $p$ if it takes a nonzero value on every $p$-regular element of $G$. In this article, we classify the quasi $p$-Steinberg characters of…

Representation Theory · Mathematics 2021-03-11 Digjoy Paul , Pooja Singla

The Gruenberg-Kegel graph (or the prime graph) $\Gamma(G)$ of a finite group $G$ is the graph whose vertex set is the set of prime divisors of $|G|$ and in which two distinct vertices $r$ and $s$ are adjacent if and only if there exists an…

Group Theory · Mathematics 2025-04-22 Mingzhu Chen , Natalia V. Maslova , Marianna R. Zinov'eva

Let P a locally finite partially ordered set, F a field, G a group, and I(P,F) the incidence algebra of P over F. We describe all the inequivalent elementary G-gradings on this algebra. If P is bounded, F is a infinite field of…

Rings and Algebras · Mathematics 2021-02-03 Humberto Luiz Talpo , Waldeck Schützer