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Let G be a finite group and N be a non-trivial normal subgroup of G, such that the average character degree of irreducible characters in Irr(G|N) is less than or equal to 16=5. Then we prove that N is solvable. Also, we prove the…

Group Theory · Mathematics 2021-09-10 Zeinab Akhlaghi

We describe an easy way how to find supercharacter theories for a finite group, if its character table is known. Namely, we show how an arbitrary partition of the conjugacy classes or of the irreducible characters can be refined to the…

Representation Theory · Mathematics 2023-03-20 Frieder Ladisch

This article is concerned with the relative McKay conjecture for finite reductive groups. Let G be a connected reductive group defined over the finite field F_q of characteristic p>0 with corresponding Frobenius map F. We prove that if the…

Representation Theory · Mathematics 2014-02-26 Olivier Brunat

It is known that, if all the real-valued irreducible characters of a finite group have odd degree, then the group has normal Sylow $2$-subgroup. We generalize this result for Sylow $p$-subgroups, for any prime number $p$, while assuming the…

Group Theory · Mathematics 2024-01-17 Nicola Grittini

We propose a new refinement of the McKay conjecture and we prove it for symmetric groups.

Representation Theory · Mathematics 2026-05-15 Eugenio Giannelli

We study the conditions under which the head characters of a finite solvable group, as defined by I. M. Isaacs, behave well with respect to restriction. We also determine the intersection of the kernels of all head characters of the group.…

Group Theory · Mathematics 2025-10-16 María José Felipe , Iris Gilabert , Lucia Sanus

We develop the concept of character level for the complex irreducible characters of finite, general or special, linear and unitary groups. We give characterizations of the level of a character in terms of its Lusztig's label and in terms of…

Representation Theory · Mathematics 2020-02-19 Robert M. Guralnick , Michael Larsen , Pham Huu Tiep

We gather tools for proving the inductive McKay--Navarro (or Galois--McKay) condition for groups of Lie type and odd primes. We use this to establish a bijection in the case of quasisimple groups of Lie type A satisfying the equivariance…

Representation Theory · Mathematics 2025-06-23 Lucas Ruhstorfer , A. A. Schaeffer Fry , Britta Späth , Jay Taylor

In 1973, I. M. Isaacs described a correspondence between characters of degree not divisible by a fixed prime $p$ of a finite solvable group $G$ and those of the normalizer of Sylow $p$-subgroup of $G$, whenever the index of the normalizer…

Representation Theory · Mathematics 2019-09-10 Carolina Vallejo

A classical theorem of John Thompson on character degrees asserts that if the degree of every ordinary irreducible character of a finite group $G$ is 1 or divisible by a prime $p$, then $G$ has a normal $p$-complement. We obtain a…

Group Theory · Mathematics 2015-06-23 Nguyen Ngoc Hung

Let p be a prime, B a p-block of a finite group G and b its Brauer correspondent. According to the Alperin-McKay Conjecture, there exists a bijection between the set of irreducible ordinary characters of height zero of B and those of b. In…

Representation Theory · Mathematics 2022-12-16 J. Miquel Martìnez , Damiano Rossi

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 construct supercharacter theories of finite unipotent groups in the orthogonal, symplectic and unitary types. Our method utilizes group actions in a manner analogous to that of Diaconis and Isaacs in their construction of supercharacters…

Representation Theory · Mathematics 2014-12-16 Scott Andrews

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

It is proven in the paper, that Carter subgroups of a finite group are conjugate if Carter subgroups in the group of induced automorphisms for every non-Abelian composition factor are conjugate.

Group Theory · Mathematics 2010-08-17 Vdovin Evgenii

There are two main constructions of supercharacter theories for a group $ G $. The first, defined by Diaconis and Isaacs, comes from the action of a group $A$ via automorphisms on our given group $G$. The second, defined by Hendrickson, is…

Rings and Algebras · Mathematics 2015-03-11 Farid Aliniaeifard

The classical It\^{o}-Michler theorem states that the degree of every ordinary irreducible character of a finite group $G$ is coprime to a prime $p$ if and only if the Sylow $p$-subgroups of $G$ are abelian and normal. In an earlier paper,…

Group Theory · Mathematics 2019-04-09 Nguyen Ngoc Hung , Pham Huu Tiep

Let G be a finite non-abelian simple group and let p be a prime. We classify all pairs (G,p) such that the sum of the complex irreducible character degrees of G is greater than the index of a Sylow p-subgroup of G. Our classification…

Group Theory · Mathematics 2013-02-07 Pablo Spiga , Alexandre Zalesski

The Alperin--McKay conjecture relates irreducible characters of a block of an arbitrary finite group to those of its $p$-local subgroups. A refinement of this conjecture was stated by the author in a previous paper. We prove that this…

Representation Theory · Mathematics 2016-06-14 Anton Evseev

We construct a few supercharacter theories for finite semidirect products with the normal subgroup of algebra group type. In the case of algebra groups, these supercharacter theories coincide with the one of P.Diaconis and I.M.Isaaks. For…

Representation Theory · Mathematics 2018-08-29 A. N. Panov