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Using a stable equivalence due to Rouquier, we prove that Broue's abelian defect group conjecture holds for 3-blocks of defect 2 whose Brauer correspondent has a unique isomorphism class of simple modules. The proof makes use of the fact,…

Group Theory · Mathematics 2014-02-26 Radha Kessar

Highest weight categories arising in Lie theory are known to be associated with finite dimensional quasi-hereditary algebras such as Schur algebras or blocks of category $\mathcal O$. An analogue of the PBW theorem will be shown to hold for…

Representation Theory · Mathematics 2014-05-01 Steffen Koenig , Julian Külshammer , Sergiy Ovsienko

We systematically classify all possible poles of superconformal blocks as a function of the scaling dimension of intermediate operators, for all superconformal algebras in dimensions three and higher. This is done by working out the…

High Energy Physics - Theory · Physics 2020-03-06 Kallol Sen , Masahito Yamazaki

We establish two consequences of the Kawamata--Morrison--Totaro cone conjecture, and prove them unconditionally in all dimensions. First, for a K-trivial variety, the natural action of its automorphism group on the set of ample divisor…

Algebraic Geometry · Mathematics 2026-05-01 Daniil Serebrennikov

The classical Morita Theorem for rings established the equivalence of three statements, involving categorical equivalences, isomorphisms between corners of finite matrix rings, and bimodule homomorphisms. A fourth equivalent statement…

Rings and Algebras · Mathematics 2022-05-17 Gene Abrams , Efren Ruiz , Mark Tomforde

Important correspondences in representation theory can be regarded as restrictions of the Morita--Tachikawa correspondence. Moreover, this correspondence motivates the study of many classes of algebras like Morita algebras and…

Representation Theory · Mathematics 2025-08-27 Tiago Cruz

As is known, every finite-dimensional algebra over a field is isomorphic to the centralizer algebra of \textbf{two} matrices. So it is fundamental to study first the centralizer algebra of a single matrix, called a centralizer matrix…

Representation Theory · Mathematics 2026-03-05 Xiaogang Li , Changchang Xi

Several structural results about permutation groups of finite rank definable in differentially closed fields of characteristic zero (and other similar theories) are obtained. In particular, it is shown that every finite rank definably…

Logic · Mathematics 2024-12-17 James Freitag , Léo Jimenez , Rahim Moosa

Let p be a prime. In this paper we provide a lower bound for the number of almost p-rational characters of degree coprime to p in the principal p-block of a finite group of order divisible by p. We further describe the p-local structure of…

Representation Theory · Mathematics 2024-09-18 Attila Maróti , J. Miquel Martínez , A. A. Schaeffer Fry , Carolina Vallejo

Any oriented 4-dimensional real vector bundle is naturally a line bundle over a bundle of quaternion algebras. In this paper we give an account of modules over bundles of quaternion algebras, discussing Morita equivalence, characteristic…

Algebraic Topology · Mathematics 2018-11-13 Martin Cadek , Michael Crabb , Jiri Vanzura

Motivated by deformation quantization, we introduced in an earlier work the notion of formal Morita equivalence in the category of $^*$-algebras over a ring $\ring C$ which is the quadratic extension by $\im$ of an ordered ring $\ring R$.…

Quantum Algebra · Mathematics 2007-05-23 Henrique Bursztyn , Stefan Waldmann

We compare lower defect groups associated with $p$-regular classes and vertices of simple modules for a block of a finite group algebra. We show that lower defect groups are contained in vertices of simple modules after suitable reordering.…

Representation Theory · Mathematics 2022-03-02 Akihiko Hida , Masao Kiyota

Let $A$ be a finite-dimensional algebra over a field of characteristic $p>0$. We use a functorial approach involving torsion pairs to construct embeddings of endomorphism algebras of basic projective $A$--modules $P$ into those of the…

Representation Theory · Mathematics 2021-04-13 Karin Erdmann , Stacey Law

The paper has three parts. It is conjectured that for every elementary amenable group G and every non-zero commutative ring k, the homological dimension of G over k is equal to the Hirsch length of G whenever G has no k-torsion. In Part I…

Group Theory · Mathematics 2013-02-19 M. R. Bridson , P. H. Kropholler

This paper is concerned with the representation theory of finite groups. According to Robinson, the truth of certain variants of Alperin's weight conjecture on the $p$-blocks of a finite group would imply some arithmetical conditions on the…

Representation Theory · Mathematics 2007-05-23 Meinolf Geck

Koenig, K\"ulshammer and Ovsienko showed that Morita equivalence classes of quasi-hereditary algebras are in one-to-one correspondence with equivalence classes of the module categories over directed bocses. In this article, we extend this…

Representation Theory · Mathematics 2022-02-02 Yuichiro Goto

In this study, we classify some soliton nilpotent Lie algebras and possible candidates in dimension 8 and 9 up to isomorphy. We focus on 1 < 2 < ::: < n type of derivations where n is the dimension of the Lie algebras. We present algorithms…

Differential Geometry · Mathematics 2016-05-20 Hulya Kadioglu

Let $k$ be an algebraically closed field of characteristic $2$, let $G$ be a finite group and let $B$ be the principal $2$-block of $kG$ with a dihedral or a generalised quaternion defect group $P$. Let also $\mathcal{T}(B)$ denote the…

Group Theory · Mathematics 2023-06-14 Çisil Karagüzel , Deniz Yılmaz

The Eaton--Moret\'o conjecture extends the recently-proven Brauer height zero conjecture to blocks with non-abelian defect group, positing equality between the minimal positive heights of a block of a finite group and its defect group. Here…

Representation Theory · Mathematics 2024-10-31 Gunter Malle , A. A. Schaeffer Fry

We show that if two $m$-homogeneous algebras have Morita equivalent graded module categories, then they are quantum-symmetrically equivalent, that is, there is a monoidal equivalence between the categories of comodules for their associated…

Quantum Algebra · Mathematics 2024-10-02 Hongdi Huang , Van C. Nguyen , Padmini Veerapen , Kent B. Vashaw , Xingting Wang