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Related papers: A remark on Rickard complexes

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We functorially identify similarity classes of line-bundle-valued quadratic forms on rank two vector bundles with isomorphism classes of pairs consisting of the degree zero and the degree one parts of the associated generalized Clifford…

Algebraic Geometry · Mathematics 2026-02-20 Soham Mondal , T. E. Venkata Balaji

Some connections between quadratic forms over the field of two elements, Clifford algebras of quadratic forms over the real numbers, real graded division algebras, and twisted group algebras will be highlighted. This allows to revisit real…

Rings and Algebras · Mathematics 2020-02-28 Alberto Elduque , Adrián Rodrigo-Escudero

As a generalization of the modular isomorphism problem we study the behavior of defect groups under Morita equivalence of blocks of finite groups over algebraically closed fields of positive characteristic. We prove that the Morita…

Representation Theory · Mathematics 2017-06-13 Gabriel Navarro , Benjamin Sambale

We show that a bimodule between block algebras which has a fusion stable endopermutation module as a source and which induces Morita equivalences between centralisers of nontrivial subgroups of a defect group induces a stable equivalence of…

Representation Theory · Mathematics 2014-02-12 Markus Linckelmann

We prove a group graded Morita equivalences version of the "butterfly theorem" on character triples. This gives a method to construct an equivalence between block extensions from another related equivalence.

Representation Theory · Mathematics 2023-04-26 Andrei Marcus , Virgilius-Aurelian Minuta

The main purpose of this paper is to prove that the extensions of a nilpotent block algebra and its Glauberman correspondent block algebra are Morita equivalent under an additional group-theoretic condition. In particular, Harris and…

Group Theory · Mathematics 2014-02-26 Lluis Puig , Yuanyang Zhou

We introduce the notion of a strong equivalence between graded algebras and prove that any partially-strongly-graded algebra by a group $G$ is strongly-graded-equivalent to the skew group algebra by a product partial action of $G$. As to a…

Rings and Algebras · Mathematics 2024-07-22 F. Abadie , R. Exel , M. Dokuchaev

In this paper we define a monoid called the equivariant Brauer semigroup for a locally compact Hausdorff groupoid E whose elements consist of Morita equivalence classes of E-dynamical systems. This construction generalizes both the…

Operator Algebras · Mathematics 2012-08-30 Jonathan Henry Brown , Geoff Goehle

Linckelmann and Murphy have classified the Morita equivalence classes of p-blocks of finite groups whose basic algebra has dimension at most 12. We extend their classification to dimension 13 and 14. As predicted by Donovan's Conjecture, we…

Representation Theory · Mathematics 2021-07-01 Benjamin Sambale

Let $\Lambda$ be the set of partitions of length $\geq 0$. We introduce an $\mathbb{N}$-graded algebra $\mathbb{A}_q^d(\Lambda)$ associated to $\Lambda$, which can be viewed as a quantization of the algebra of partitions defined by Reineke.…

Combinatorics · Mathematics 2021-06-08 Neil J. Y. Fan , Changjian Fu , Liangang Peng

We compute the Hochschild cohomology of any block of $q$-Schur algebras. We focus the even part of this Hochschild cohomology ring. To compute the Hochschild cohomology of $q$-Schur algebras, we prove the following two results: first, we…

Representation Theory · Mathematics 2016-04-27 Mayu Tsukamoto

The Rickard complex of a braid with strands colored by positive integers is a chain complex of singular Soergel bimodules. The complex determines the colored triply-graded homology and colored sl(N) homology of the braid closure, when…

Geometric Topology · Mathematics 2026-04-21 Joshua Wang

Rickard complexes in the context of categorified quantum groups can be used to construct braid group actions. We define and study certain natural deformations of these complexes which we call curved Rickard complexes. One application is to…

Quantum Algebra · Mathematics 2020-12-03 Sabin Cautis , Aaron D. Lauda , Joshua Sussan

We compute the Hochschild homology of the differential graded category of perfect curved modules over suitable curved rings, giving what might be termed "de Rham models" for such. This represents a generalization of previous results by…

K-Theory and Homology · Mathematics 2024-08-27 Benjamin Briggs , Mark E. Walker

We introduce block pro-fusion systems for blocks of profinite groups, prove a profinite version of Puig's structure theorem for nilpotent blocks, and use it to show that there is only one Morita equivalence class of blocks having the…

Representation Theory · Mathematics 2025-04-15 Florian Eisele , Ricardo J. Franquiz Flores , John W. MacQuarrie

We consider central simple $K$-algebras which happen to bedifferential graded $K$-algebras. Two such algebras $A$ and $B$are considered equivalent if there are bounded complexes of finite dimensional$K$-vector spaces $C_A$ and $C_B$ such…

Rings and Algebras · Mathematics 2023-08-21 Alexander Zimmermann

Brauer algebras form a tower of cellular algebras. There is a well-defined notion of limiting blocks for these algebras. In this paper we give a complete description of these limiting blocks over any field of positive characteristic. We…

Representation Theory · Mathematics 2012-12-27 Oliver King

We introduce a new type of equivalence between blocks of finite group algebras called an almost isotypy. An almost isotypy restricts to a weak isotypy in Brou\'{e}'s original definition, and it is slightly weaker than Linckelmann's version.…

Representation Theory · Mathematics 2025-02-26 Xin Huang

We prove Turner's conjecture, which describes the blocks of the Hecke algebras of the symmetric groups up to derived equivalence as certain explicit Turner double algebras. Turner doubles are Schur-algebra-like `local' objects, which…

Representation Theory · Mathematics 2016-03-15 Anton Evseev , Alexander Kleshchev

In this paper we investigate equivariant Morita theory for algebras with momentum maps and compute the equivariant Picard groupoid in terms of the Picard groupoid explicitly. We consider three types of Morita theory: ring-theoretic…

Quantum Algebra · Mathematics 2015-05-18 Stefan Jansen , Nikolai Neumaier , Gregor Schaumann , Stefan Waldmann