English
Related papers

Related papers: Splendid Morita equivalences for principal blocks …

200 papers

We show that the splendid Rickard complexes for blocks with Klein four defect groups constructed by Rickard and Linckelmann descend to non-split fields. As a corollary, Navarro's refinement of the Alperin-McKay conjecture holds for blocks…

Group Theory · Mathematics 2021-10-18 Xin Huang

In by now classical work, K. Erdmann classified blocks of finite groups with dihedral defect groups (and more generally algebras of dihedral type) up to Morita equivalence. In the explicit description by quivers and relations of such…

Representation Theory · Mathematics 2008-09-09 Thorsten Holm , Guodong Zhou

For any block of a finite group over an algebraically closed field of characteristic $2$ which has dihedral, semidihedral, or generalized quaternion defect groups, we determine explicitly the decomposition of the associated diagonal…

Representation Theory · Mathematics 2025-09-19 Robert Boltje , Serge Bouc , Deniz Yılmaz

We introduce strong Morita equivalence for inverse semigroups. This notion encompasses Mark Lawson's concept of enlargement. Strongly Morita equivalent inverse semigroups have Morita equivalent universal groupoids in the sense of Paterson…

Operator Algebras · Mathematics 2009-01-20 Benjamin Steinberg

By results of the second author, a source algebra equivalence between two $p$-blocks of finite groups induces an equivalence between the categories of cohomological Mackey functors associated with these blocks, and a splendid derived…

Representation Theory · Mathematics 2018-07-24 Markus Linckelmann , Baptiste Rognerud

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 prove that for any finite-dimensional differential graded algebra with separable semisimple part the category of perfect modules is equivalent to a full subcategory of the category of perfect complexes on a smooth projective scheme with…

Algebraic Geometry · Mathematics 2020-03-18 Dmitri Orlov

Let k be an algebraically closed field of characteristic 2, and let W be the ring of infinite Witt vectors over k. Suppose G is a finite group, and B is a block of kG with dihedral defect group D which is Morita equivalent to the principal…

Representation Theory · Mathematics 2009-04-02 Frauke M. Bleher

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

For finite groups $G$ with non-abelian, trivial intersection Sylow $p$-subgroups, the analysis of the Loewy structure of the centre of a block allows us to deduce that a stable equivalence of Morita type does not induce an algebra…

Representation Theory · Mathematics 2016-08-10 Inga Schwabrow

We consider a block $B$ of a finite group with defect group $D \cong (C_{2^m})^n$ and inertial quotient $\mathbb{E}$ containing a Singer cycle (an element of order $2^n-1$). This implies $\mathbb{E} = E \rtimes F$, where $E \cong…

Representation Theory · Mathematics 2020-01-09 Elliot Mckernon

We give a complete description of the Morita equivalence classes of blocks with elementary abelian defect groups of order 8 and of the derived equivalences between them. A consequence is the verification of Brou\'e's abelian defect group…

Representation Theory · Mathematics 2014-09-23 Charles W. Eaton

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

The Morita context provided by an exact module category over a finite tensor category gives a two-object bicategory with duals. Right and left duals of objects in the module category are given by internal Homs and coHoms, respectively. We…

Quantum Algebra · Mathematics 2023-10-19 Jürgen Fuchs , César Galindo , David Jaklitsch , Christoph Schweigert

In this paper we investigate gradings on tame blocks of group algebras whose defect group is dihedral. We classify gradings on an arbitrary dihedral block up to graded Morita equivalence. We do this by computing the group of outer…

Representation Theory · Mathematics 2010-04-21 Dusko Bogdanic

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 classify the Morita equivalence classes of blocks with elementary abelian defect groups of order $16$ with respect to a complete discrete valuation ring with algebraically closed residue field of characteristic two. As a consequence,…

Group Theory · Mathematics 2019-05-16 Charles W. Eaton

Categorical equivalences between block algebras of finite groups - such as Morita and derived equivalences - are well-known to induce character bijections which commute with the Galois groups of field extensions. This is the motivation for…

Representation Theory · Mathematics 2018-02-16 Radha Kessar , Markus Linckelmann

A well-known result of Scopes states that there are only finitely many Morita equivalence classes of $p$-blocks of symmetric groups with a given weight (or defect). In this note we investigate a lower bound on the number of those Morita…

Representation Theory · Mathematics 2018-09-21 Benjamin Sambale

Taking advantage of the quantale-theoretic description of \'etale groupoids we study principal bundles, Hilsum-Skandalis maps, and Morita equivalence in terms of modules on inverse quantal frames. The Hilbert module description of quantale…

Category Theory · Mathematics 2021-09-06 Juan Pablo Quijano , Pedro Resende