Search results for "Character Theory"

2-Brauer correspondent blocks with one simple module

2017

Abstract One of the main problems in representation theory is to understand the exact relationship between Brauer corresponding blocks of finite groups. The case where the local correspondent has a unique simple module seems key. We study this situation for 2-blocks.

Some applications of a fundamental theorem by Gluck and Wolf in the character theory of finite groups

1986

Characters and Blocks of Finite Groups

1998

This is a clear, accessible and up-to-date exposition of modular representation theory of finite groups from a character-theoretic viewpoint. After a short review of the necessary background material, the early chapters introduce Brauer characters and blocks and develop their basic properties. The next three chapters study and prove Brauer's first, second and third main theorems in turn. These results are then applied to prove a major application of finite groups, the Glauberman Z*-theorem. Later chapters examine Brauer characters in more detail. The relationship between blocks and normal subgroups is also explored and the modular characters and blocks in p-solvable groups are discussed. Fi…

On groups having a p-constant character

2020

Let G G be a finite group, and p p a prime number; a character of G G is called p p -constant if it takes a constant value on all the elements of G G whose order is divisible by p p . This is a generalization of the very important concept of characters of p p -defect zero. In this paper, we characterize the finite p p -solvable groups having a faithful irreducible character that is p p -constant and not of p p -defect zero, and we will show that a non- p p -solvable group with this property is an almost-simple group.

Character sums and double cosets

2008

Abstract If G is a p-solvable finite group, P is a self-normalizing Sylow p-subgroup of G with derived subgroup P ′ , and Ψ is the sum of all the irreducible characters of G of degree not divisible by p, then we prove that the integer Ψ ( P ′ z P ′ ) is divisible by | P | for all z ∈ G . This answers a question of J. Alperin.

On the orders of zeros of irreducible characters

2009

Let G be a finite group and p a prime number. We say that an element g in G is a vanishing element of G if there exists an irreducible character χ of G such that χ (g) = 0. The main result of this paper shows that, if G does not have any vanishing element of p-power order, then G has a normal Sylow p-subgroup. Also, we prove that this result is a generalization of some classical theorems in Character Theory of finite groups. © 2008 Elsevier Inc. All rights reserved.

Character correspondences in blocks with normal defect groups

2014

Abstract In this paper we give an extension of the Glauberman correspondence to certain characters of blocks with normal defect groups.

Penal Contextualism and Ideational Frameworks: A Guide for the Perplexed

2017

In my paper, I attempt a critical review of Nicola Lacey’s book In Search of Criminal Responsibility, by arguing, firstly, that she gives the categories of “character responsibility” and “capacity responsibility” an over-inclusive account, which results from her filling each of them with views that are not only disparate but also based, at least in part, on conflicting principles; and, secondly, that Lacey’s spelling out of various conceptions of “criminal responsibility” necessarily entails an underlying unitary definition of its subject matter, that is, the concept of “criminal responsibility,” which seems to conflict with her (version of) penal contextualism.

Primitive characters of subgroups ofM-groups

1995

One of the hardest areas in the Character Theory of Solvable Groups continues to be the monomial groups. A finite group is said to be an M-group (or monomial) if all of its irreducible characters are monomial, that is to say, induced from linear characters. Two are still the main problems on M-groups: are Hall subgroups of M groups monomial? Under certain oddness hypothesis, are normal subgroups of M-groups monomial? In both cases there is evidence that this could be the case: the primitive characters of the subgroups in question are the linear characters. This is the best result up to date ([4], [6]). Recently, some idea appears to be taking form. In [14], T. Okuyama proved that if G is an…

Irreducible characters of $3'$-degree of finite symmetric, general linear and unitary groups

2018

Abstract Let G be a finite symmetric, general linear, or general unitary group defined over a field of characteristic coprime to 3. We construct a canonical correspondence between irreducible characters of degree coprime to 3 of G and those of N G ( P ) , where P is a Sylow 3-subgroup of G . Since our bijections commute with the action of the absolute Galois group over the rationals, we conclude that fields of values of character correspondents are the same.