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Related papers: Donovan's conjecture, blocks with abelian defect g…

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We give a reduction of Donovan's conjecture for abelian groups to a similar statement for quasisimple groups. Consequently we show that Donovan's conjecture holds for abelian $2$-groups.

Representation Theory · Mathematics 2018-03-12 Charles Eaton , Michael Livesey

We consider Donovan's conjecture in the context of blocks of groups $G$ with defect group $D$ and normal subgroups $N \lhd G$ such that $G=C_D(D\cap N)N$, extending similar results for blocks with abelian defect groups. As an application we…

Representation Theory · Mathematics 2020-06-22 Charles W. Eaton , Michael Livesey

We give a classification, up to Morita equivalence, of 2-blocks of quasi-simple groups with abelian defect groups. As a consequence, we show that Donovan's conjecture holds for elementary abelian 2-groups, and that the entries of the Cartan…

Group Theory · Mathematics 2013-05-27 Charles W. Eaton , Radha Kessar , Burkhard Külshammer , Benjamin Sambale

We define a new invariant for a $p$-block, the strong Frobenius number, which we use to address the problem of reducing Donovan's conjecture to normal subgroups of index p. As an application we use the strong Frobenius number to complete…

Representation Theory · Mathematics 2018-06-08 Charles Eaton , Michael Livesey

Let $k$ be an algebraically closed field of characteristic $p$, and let $\mathcal{O}$ be either $k$ or its ring of Witt vectors $W(k)$. Let $G$ a finite group and $B$ a block of $\mathcal{O}G$ with normal abelian defect group and abelian…

Representation Theory · Mathematics 2018-08-23 David Benson , Radha Kessar , Markus Linckelmann

Let $\ell$ be a prime number. We show that the Morita Frobenius number of an $\ell$-block of a quasi-simple finite group is at most 4 and that the strong Frobenius number is at most $4|D|^2!$, where D denotes a defect group of the block. We…

Representation Theory · Mathematics 2019-08-05 Niamh Farrell , Radha Kessar

We classify up to Morita equivalence all blocks whose defect groups are Suzuki $2$-groups. The classification holds for blocks over a suitable discrete valuation ring as well as for those over an algebraically closed field, and in fact…

Group Theory · Mathematics 2024-09-16 Charles W. Eaton

In the representation theory of finite groups, there is a well-known and important conjecture due to M. Brou\'e. He conjectures that, for any prime p, if a p-block A of a finite group G has an abelian defect group P, then A and its Brauer…

Representation Theory · Mathematics 2015-03-17 Shigeo Koshitani , Jürgen Müller , Felix Noeske

We study numerical invariants of 2-blocks with minimal nonabelian defect groups. These groups were classified by R\'edei. If the defect group is also metacyclic, then the block invariants are known. In the remaining cases there are only two…

Representation Theory · Mathematics 2010-12-09 Benjamin Sambale

In this paper, we classify all $2$-blocks for which the defect groups are abelian and the inertial quotient has prime order. As a consequence, we prove that Brou\'e's abelian defect group conjecture holds for all blocks under consideration…

Group Theory · Mathematics 2026-04-14 Qianhu Zhou , Kun Zhang

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

In representation theory of finite groups, there is a well-known and important conjecture due to M. Brou\'e. He conjectures that, for any prime $p$, if a $p$-block $A$ of a finite group $G$ has an abelian defect group $P$, then $A$ and its…

Representation Theory · Mathematics 2009-06-30 Shigeo Koshitani , Jürgen Müller

We characterise the Morita equivalence classes of blocks with extraspecial defect groups $p_+^{1+2}$ for $p \geq 5$, and so show that Donovan's conjecture and the Alperin-McKay conjecture hold for such $p$-groups. For $p=3$ we reduce…

Representation Theory · Mathematics 2023-10-05 Jianbei An , Charles W. Eaton

Recently, a new conjecture on the degrees of the irreducible Brauer characters of a finite group was presented by the second author. In this paper we propose a 'local' version of this conjecture for blocks B of finite groups, giving a lower…

Group Theory · Mathematics 2007-05-23 Thorsten Holm , Wolfgang Willems

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

In the representation theory of finite groups, Brou\'e's abelian defect group conjecture says that for any prime p if a p-block A of a finite group G has an abelian defect group P, then A and its Brauer corresponding block B of the…

Representation Theory · Mathematics 2013-09-30 Shigeo Koshitani , Jürgen Müller , Felix Noeske

We construct blocks of finite groups with arbitrarily large Morita Frobenius numbers, an invariant which determines the size of the minimal field of definition of the associated basic algebra. This answers a question of Benson and Kessar.…

Representation Theory · Mathematics 2020-06-26 Florian Eisele , Michael Livesey

In this note we give applications of recent results coming mostly from the third paper of this series. It is shown that the number of irreducible characters in a $p$-block of a finite group with abelian defect group $D$ is bounded by $|D|$…

Representation Theory · Mathematics 2015-03-31 Benjamin Sambale

We show that perverse equivalences between module categories of finite-dimensional algebras preserve rationality. As an application, we give a connection between some famous conjectures from the modular representation theory of finite…

Representation Theory · Mathematics 2018-11-05 Joseph Chuang , Radha Kessar

The first author has recently classified the Morita equivalence classes of 2-blocks B of finite groups with elementary abelian defect group of order 32. In all but three cases he proved that the Morita equivalence class determines the…

Representation Theory · Mathematics 2020-11-16 Cesare G. Ardito , Benjamin Sambale
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