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We define the notion of a semicharacter of a group G : A function from the group to C*, whose restriction to any abelian subgroup is a homomorphism. We conjecture that for any finite group, the order of the group of semicharacters is…

Group Theory · Mathematics 2013-11-12 Gil Alon

An approach to a classification of groups generated by 3-state automata over a 2-letter alphabet and the current progress in this direction are presented. Several results related to the whole class are formulated. In particular, all finite,…

Properties of higher characters are developed and applied to symmetric products and Frobenius algebras. A `constructive' proof of the Gel'fand-Kolmogorov theorem is given. Generalisations of that theorem and the Nullstellensatz to symmetric…

Rings and Algebras · Mathematics 2015-06-26 V. M. Buchstaber , E. G. Rees

Brauer Theory for a finite group can be viewed as a method for comparing the representations of the group in characteristic 0 with those in prime characteristic. Here we generalize much of the machinery of Brauer theory to the setting of…

Representation Theory · Mathematics 2013-01-24 John MacQuarrie , Peter Symonds

We prove a variation of Thompson's Theorem. Namely, if the first column of the character table of a finite group $G$ contains only two distinct values not divisible by a given prime number $p>3$, then $O^{pp'pp'}(G)=1$. This is done by…

Group Theory · Mathematics 2019-04-16 Eugenio Giannelli , Noelia Rizo , Mandi Schaeffer Fry

We investigate a beautiful conjecture of T. Wilde on character values and element orders of finite groups. We reduce it to a statement on nearly simple groups that can be checked ``prime by prime". For these groups, we show that a strong…

Representation Theory · Mathematics 2026-05-07 Gunter Malle , Gabriel Navarro , Pham Huu Tiep

We prove, for primes $p\ge5$, two inequalities between the fundamental invariants of Brauer $p$-blocks of finite quasi-simple groups: the number of characters in the block, the number of modular characters, the number of height zero…

Representation Theory · Mathematics 2018-04-04 Gunter Malle

Let B be a block of a finite group G with defect group D. We prove that the exponent of the center of D is determined by the character table of G. In particular, we show that D is cyclic if and only if B contains a "large" family of…

Representation Theory · Mathematics 2020-07-10 Benjamin Sambale

For a subgroup $H$ of a finite group $G$, the Frobenius graph $\Gamma(G, H)$ records the constituents of the restrictions to $H$ of the irreducible characters of $G$. We investigate when this graph has diameter 3.

Group Theory · Mathematics 2024-07-12 Thomas Breuer , László Héthelyi , Erzsébet Horváth , Burkhard Külshammer

In this note we introduce and characterize a class of finite groups for which the element orders satisfy a certain inequality. This is contained in some well-known classes of finite groups.

Group Theory · Mathematics 2018-05-24 Marius Tărnăuceanu

We define invariants of braids rather than invariants of conjugacy classes of braids. For any pure three-braid we give effective upper and lower bounds for these invariants. This is done in terms of a natural syllable decomposition of the…

Geometric Topology · Mathematics 2023-12-20 Burlind Joricke

We give an analog of Frobenius' theorem about the factorization of the group determinant on the group algebra of finite abelian groups and we extend it into dihedral groups and generalized quaternion groups. Furthermore, we describe the…

Representation Theory · Mathematics 2014-05-09 N. Yamaguchi

The purpose of the present paper is to investigate a hypergroup arising from irreducible characters of a compact group G and a closed subgroup of G with finite index. The convolution of this hypergroup is introduced by inducing irreducible…

Representation Theory · Mathematics 2016-05-13 Hebert Heyer , Satoshi Kawakami , Tatsuya Tsurii , Satoe Yamanaka

This paper shows that groups of order $64$ are uniquely determined up to isomorphism by their Tables of Marks. This then resolves a previously posed question about whether all groups of order less than $96$ are determined by their Tables of…

Group Theory · Mathematics 2018-10-12 Peter Bonart

Much can be learned about a finite group from its character table, but sometimes that table can be difficult to compute. Supercharacter theories are generalizations of character theory defined by P. Diaconis and I.M. Isaacs, in which…

Group Theory · Mathematics 2009-05-22 Anders O. F. Hendrickson

In this article, we study the elements with disconnected centralizer in the Brauer complex associated to a simple algebraic group G defined over a finite field with corresponding Frobenius map F and derive the number of F-stable semisimple…

Representation Theory · Mathematics 2010-03-18 Olivier Brunat

We classify finite groups with a small average number of zeros in the character table.

Group Theory · Mathematics 2021-06-04 Alexander Moretó

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

We prove that the number of irreducible real characters in a nilpotent block of a finite group is locally determined. We further conjecture that the Frobenius-Schur indicators of those characters can be computed for p=2 in terms of the…

Representation Theory · Mathematics 2023-02-01 Benjamin Sambale

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