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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

This paper will prove that: 1. $G$ has a block only having linear ordinary characters if and only if $G$ is a $p$-nilpotent group with an abelian Sylow $p$-subgroup; 2. $G$ has a block only having linear Brauer characters if and only if…

Representation Theory · Mathematics 2011-03-02 Jiwen Zeng

Using computational methods, we determine the irreducible Brauer characters of the automorphism group of the Chevalley group F_4(2), up to one parameter and one consistency issue.

Group Theory · Mathematics 2024-12-16 Gerhard Hiss , Frank Lübeck

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 consider real versions of Brauer's k(B) conjecture, Olsson's conjecture and Eaton's conjecture. We prove the real version of Eaton's conjecture for 2-blocks of groups with cyclic defect group and for the principal 2-blocks of groups with…

Representation Theory · Mathematics 2011-03-17 Laszlo Hethelyi , Erzsebet Horvath , Endre Szabo

If $G$ is a solvable group and $p$ is a prime, then the Fong-Swan theorem shows that given any irreducible Brauer character $\phi$ of $G$, there exists a character $\chi \in \irrg$ such that $\chi^o = \phi$, where $^o$ denotes the…

Group Theory · Mathematics 2011-12-19 James P. Cossey , Mark L. Lewis

Using the classification of finite simple groups we prove Alperin's weight conjecture and the character theoretic version of Broue's abelian defect group conjecture for 2-blocks of finite groups with an elementary abelian defect group of…

Representation Theory · Mathematics 2010-12-17 Radha Kessar , Shigeo Koshitani , Markus Linckelmann

Let $G$ be a finite group, $p$ a prime number and $P$ a Sylow $p$-subgroup of $G$. Recently, G. Malle, G. Navarro, and P. H. Tiep conjectured that the number of $p$-Brauer characters of $G$ coincides with that of the normaliser ${\bf…

Representation Theory · Mathematics 2025-02-19 Zhicheng Feng , J. Miquel Martínez , Damiano Rossi

The longstanding Alperin weight conjecture and its blockwise version have been reduced to simple groups recently by Navarro, Tiep, Spaeth and Koshitani. Thus, to prove this conjecture, it suffices to verify the corresponding inductive…

Representation Theory · Mathematics 2019-01-23 Conghui Li

A complex irreducible character of a finite group G is said to be p-constant, for some prime p dividing the order of G, if it takes constant value at the set of p-singular elements of G. In this paper we classify irreducible p-constant…

Group Theory · Mathematics 2017-02-07 Marco Antonio Pellegrini

A super-Brauer character theory of a group $G$ and a prime $p$ is a pair consisting of a partition of the irreducible $p$-Brauer characters and a partition of the $p$-regular elements of $G$ that satisfy certain properties. We classify the…

Group Theory · Mathematics 2017-03-02 Xiaoyou Chen , Mark L. Lewis

We characterise finite groups such that for an odd prime $p$ all the irreducible characters in its principal $p$-block have odd degree. We show that this situation does not occur in non-abelian simple groups of order divisible by $p$ unless…

Representation Theory · Mathematics 2017-10-05 Eugenio Giannelli , Gunter Malle , Carolina Vallejo

We prove Brauer's k(B)-Conjecture for the 3-blocks with abelian defect groups of rank at most 5 and for all 3-blocks of defect at most 4. For this purpose we develop a computer algorithm to construct isotypies based on a method of Usami and…

Representation Theory · Mathematics 2019-11-26 Cesare G. Ardito , Benjamin Sambale

We show (among other things) that Brauer's k(B)-conjecture holds for defect groups with are central extensions of metacyclic 2-groups by cyclic groups. The same holds for defect groups which contain a central cyclic subgroup of index at…

Representation Theory · Mathematics 2010-12-21 Benjamin Sambale

We determine the numerical invariants of blocks with defect group D_{2^n} * C_{2^m} = Q_{2^n} * C_{2^m} (central product), where n > 2 and m > 1. As a consequence, we prove Brauer's k(B)-conjecture, Olsson's conjecture (and more generally…

Representation Theory · Mathematics 2011-05-26 Benjamin Sambale

A new conjecture on characters of finite groups, related to the McKay conjecture, was proposed recently by the first and third authors. In this paper, we prove it for $p$-solvable groups when $p$ is odd.

Representation Theory · Mathematics 2025-06-16 Alexander Moretó , Gabriel Navarro , Noelia Rizo

We prove that if $B$ is a $p$-block with non-trivial defect group $D$ of a finite $p$-solvable group $G$, then $\ell(B) < p^r$, where $r$ is the sectional rank of $D$. We remark that there are infinitely many $p$-blocks $B$ with non-Abelian…

Representation Theory · Mathematics 2016-11-08 Gunter Malle , Geoffrey R. Robinson

We consider $p$-blocks with abelian defect groups and in the first part prove a relationship between its Loewy length and that for blocks of normal subgroups of index $p$. Using this, we show that if $B$ is a $2$-block of a finite group…

Representation Theory · Mathematics 2016-08-01 Charles W. Eaton , Michael Livesey

As a sequel to [CS13b], we verify the so-called inductive AM-condition introduced in [Sp12] for simple groups of type A and blocks with maximal defect. This is part of the program set up to verify the Alperin-McKay conjecture through its…

Representation Theory · Mathematics 2014-03-20 Marc Cabanes , Britta Spaeth

We show that a conjecture of Giannelli on character degrees of height zero characters holds for blocks with a cyclic or Klein four defect group.

Representation Theory · Mathematics 2025-09-03 Markus Linckelmann