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For any finite group G it is an interesting question to ask which ordinary irreducible representations of G remain irreducible in a given characteristic p. We answer this question for p=2 when G is the proper double cover of the alternating…

Representation Theory · Mathematics 2020-08-06 Matthew Fayers

In this work, we establish a relationship between the sum of irreducible character degrees and the number of twisted involutions associated with the automorphisms of a finite group. We develop algorithmic frameworks for evaluating these…

Representation Theory · Mathematics 2026-05-25 Venkata Subbaiah Yerrapati , Rahul Dixit , Ajay Kumar Shukla

Let $d$ be a positive integer. We study the proportion of irreducible characters of infinite families of irreducible Coxeter groups whose values evaluated on a fixed element $g$ are divisible by $d$. For Coxeter groups of types $A_n, B_n$…

Representation Theory · Mathematics 2025-04-29 Jyotirmoy Ganguly , Rohit Joshi

We show that the two cuspidal unipotent characters of a finite Chevalley group $E_7(q)$ have Schur index~2, provided that $q$ is an even power of a (sufficiently large) prime number $p$ such that $p\equiv 1 \bmod 4$. The proof uses a…

Representation Theory · Mathematics 2007-05-23 Meinolf Geck

Let $G$ be a finite $p$-group and $\chi,\psi$ be irreducible characters of $G$. We study the character $\chi\psi$ when $\chi\psi$ has at most $p-1$ distinct irreducible constituents.

Group Theory · Mathematics 2007-05-23 Edith Adan-Bante

In representation theory of finite groups an important role is played by irreducible characters of p-defect 0, for a prime p dividing the group order. These are exactly those vanishing at the p-singular elements. In this paper we generalize…

Group Theory · Mathematics 2014-11-13 M. A. Pellegrini , A. Zalesski

We study the complex irreducible representations of special linear, symplectic, orthogonal and unitary groups over principal ideal local rings of length two. We construct a canonical correspondence between the irreducible representations of…

Representation Theory · Mathematics 2011-04-25 Pooja Singla

Recently the strings and the string number of self-maps were used in the computation of the algebraic entropy of special group endomorphisms. We introduce two special kinds of strings, and their relative string numbers. We show that a…

Group Theory · Mathematics 2010-12-23 Dikran Dikranjan , Anna Giordano Bruno , Simone Virili

For an irreducible character $\chi$ of a finite group $G$, the codegree of $\chi$ is defined as $|G:\ker(\chi)|/\chi(1)$. In this paper, we determine finite nonsolvable groups with exactly three nonlinear irreducible character codegrees,…

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

Let $G$ be a finite nilpotent group, $\chi$ and $\psi$ be irreducible complex characters of $G$ of prime degree. Assume that $\chi(1)=p$. Then either the product $\chi\psi$ is a multiple of an irreducible character or $\chi\psi$ is the…

Group Theory · Mathematics 2008-03-25 Edith Adan-Bante

We use the structure of finite-dimensional graded algebras to develop the theory of antilinear representations of finite $C_2$-graded groups. A finite $C_2$-graded group is a finite group with a subgroup of index 2. In this theory the…

Representation Theory · Mathematics 2021-08-30 Dmitriy Rumynin , James Taylor

In this work, we classify all finite groups such that for every field extension F of \mathbb{Q}, F is the field of values of at most 3 irreducible characters.

Group Theory · Mathematics 2023-01-02 Juan Martínez

In this paper, we answer affirmatively a question of H S Sim on representations in characteristic $0$, for a class of metabelian groups. Moreover, we provide examples to point out that the analogous answer is no longer valid if the solvable…

Representation Theory · Mathematics 2021-06-29 Soham Swadhin Pradhan , B. Sury

We consider irreducible representations of finite quandles over $\mathbb{C}$. For $Q$ a finite quandle whose inner automorphism group $Inn(Q)$ have trivial Schur multipliers, we prove that the irreducible representations of $Q$ can be…

Representation Theory · Mathematics 2026-04-15 Mohamad Maassarani

Several recent problems in the representation theory of finite groups require determining whether certain characters of almost simple groups belong to the principal block. Since the values of these characters are not yet known, we employ…

Representation Theory · Mathematics 2025-08-05 Richard Lyons , J. Miquel Martínez , Gabriel Navarro , Pham Huu Tiep

We give a new formula for the values of an irreducible character of the symmetric group S_n indexed by a partition of rectangular shape. Some observations and a conjecture are given concerning a generalization to arbitrary shapes.

Combinatorics · Mathematics 2007-05-23 Richard P. Stanley

In this paper we obtained the formula for the number of irreducible polynomials with degree $n$ over finite fields of characteristic two with given trace and subtrace. This formula is a generalization of the result of Cattell et al.(2003)…

Number Theory · Mathematics 2014-07-02 Won-Ho Ri , Gum-Chol Myong , Ryul Kim , Chang-Il Rim

A recurring theme in finite group theory is understanding how the structure of a finite group is determined by the arithmetic properties of group invariants. There are results in the literature determining the structure of finite groups…

Group Theory · Mathematics 2025-04-04 Christopher A. Schroeder , Hung P. Tong-Viet

Let $G$ be a finite group, and $\alpha$ a nontrivial character of $G$. The McKay graph $\mathcal{M}(G,\alpha)$ has the irreducible characters of $G$ as vertices, with an edge from $\chi_1$ to $\chi_2$ if $\chi_2$ is a constituent of…

Group Theory · Mathematics 2020-07-22 M. W. Liebeck , A. Shalev , Pham Huu Tiep

It is well known that the number of real irreducible characters of a finite group G coincides with the number of real conjugacy classes of G. Richard Brauer has asked if the number of irreducible characters with Frobenius-Schur indicator 1…

Representation Theory · Mathematics 2022-12-19 John Murray , Benjamin Sambale