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Related papers: Mackey functors and sharpness for fusion systems

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Systematically using the language of groupoids, we survey the theory of global Mackey functors, global Green functors and global power functors. Given a global power functor, we study rings with similar operations. The example of n-class…

Representation Theory · Mathematics 2013-01-22 Nora Ganter

We develop and extend the theory of Mackey functors as an application of enriched category theory. We define Mackey functors on a lextensive category $\E$ and investigate the properties of the category of Mackey functors on $\E$. We show…

Category Theory · Mathematics 2007-06-21 Ross Street , Elango Panchadcharam

We introduce the notion of a pro-fusion system on a pro-p group, which generalizes the notion of a fusion system on a finite p-group. We also prove a version of Alperin's Fusion Theorem for pro-fusion systems.

Representation Theory · Mathematics 2017-05-17 Radu Stancu , Peter Symonds

We determine for which known finite simple groups $G$ and which primes $p$ the $p$-fusion system of $G$ is simple. This means first collecting together the results that were already known (and correcting two errors made in an earlier study…

Group Theory · Mathematics 2022-11-08 Bob Oliver , Albert Ruiz

For half a century, Mackey and Green functors have been successfully used to model the induction and restriction maps which are ubiquitous in the representation theory of finite groups. In the examples, the latter maps are typically…

Representation Theory · Mathematics 2024-07-16 Ivo Dell'Ambrogio

The box product of Mackey functors has been studied extensively in Lewis's notes. As shown in Thevenaz and Webb's paper, a Mackey functor may be identified with a module over a certain algebra, called the Mackey algebra. We aim at…

Algebraic Topology · Mathematics 2015-09-24 Zhulin Li

We introduce endo-permutation Mackey functors and the Mackey-Dade group of a $p$-group and study their basic properties. We exhibit relations between the Mackey-Dade group of a finite $p$-group $P$ and the Dade groups of the Weyl groups of…

Group Theory · Mathematics 2016-09-16 Olcay Coşkun

In this paper, we give a description of polynomial functors from (finitely generated free) groups to abelian groups in terms of non-linear Mackey functors generalizing those given in a paper of Baues-Dreckmann-Franjou-Pirashvili published…

Algebraic Topology · Mathematics 2012-09-12 Manfred Hartl , Teimuraz Pirashvili , Christine Vespa

Let $\mathcal F$ be a saturated fusion system on a finite $p$-group $S$, and let $P$ be a strongly $\mathcal F$-closed subgroup of $S$. We define the concept ``$\mathcal F$-essential subgroups with respect to $P$" which are some proper…

Group Theory · Mathematics 2023-04-10 M. Yasir Kızmaz

The purpose of this article is threefold: Firstly, we propose some enhancements to the existing definition of 6-functor formalisms. Secondly, we systematically study the category of kernels, which is a certain 2-category attached to every…

Category Theory · Mathematics 2024-10-18 Claudius Heyer , Lucas Mann

We examine the projective dimensions of Mackey functors and cohomological Mackey functors. We show over a field of characteristic $p$ that cohomological Mackey functors are Gorenstein if and only if Sylow $p$-subgroups are cyclic or…

Representation Theory · Mathematics 2015-03-16 S. Bouc , R. Stancu , P. J. Webb

The aim of this paper is to generalise the notion of p-stability to fusion systems. We study the question how Qd(p) is involved in finite simple groups. We show that with a single exception a simple group involving Qd(p) has a subgroup…

Group Theory · Mathematics 2017-01-10 László Héthelyi , Magdolna Szőke , Alexandre Zalesski

To study induced representation of some class of groups, Mackey's theory is very useful. In this paper, we consider some generalization of Mackey's theory for locally profinite groups. In particular, we give conditions on groups under which…

Group Theory · Mathematics 2022-03-29 Yuki Yamamoto

Over any partially ordered abelian group whose positive cone is closed in an appropriate sense and has finitely many faces, modules that satisfy a weak finiteness condition admit finite primary decompositions. This conclusion rests on the…

Commutative Algebra · Mathematics 2020-08-12 Ezra Miller

We develop a theory of separable ring extensions and separable functors for nonunital rings in the setting of firm modules. We prove nonunital analogues of classical results on functorial separability and semisimplicity, and apply these…

Rings and Algebras · Mathematics 2026-05-26 Patrik Lundström

In this paper, we find some exotic fusion systems which have non-trivial strongly closed subgroups, and we prove these fusion systems are also not realizable by p-blocks of finite groups.

Group Theory · Mathematics 2017-01-10 Heguo Liu , Xingzhong Xu , Jiping Zhang

We exhibit gluing properties of cluster tilting subcategories in exact $\infty$-categories within the framework of perverse schobers on surfaces with boundary. These results are based on a study of the restriction functors from global…

Representation Theory · Mathematics 2025-10-14 Merlin Christ

We introduce separable functors of the second kind (or $H$-separable functors) and $H$-Maschke functors. $H$-separable functors are generalizations of separable functors. Various necessary and sufficient conditions for a functor to be…

Rings and Algebras · Mathematics 2007-05-23 S. Caenepeel , G. Militaru

In this paper we establish sharp weighted bounds (Buckley type theorems) for one{sided maximal and fractional integral operators in terms of one{sided $A_p$ characteristics. Appropriate sharp bounds for strong maximal functions, multiple…

Functional Analysis · Mathematics 2014-03-04 Vakhtang Kokilashvili , Alexander Meskhi , Muhammad Asad Zaighum

We expound a concise construction of finite groups and groupoids whose Cayley graphs satisfy graded acyclicity requirements. Our acyclicity criteria concern cyclic patterns formed by coset-like configurations w.r.t. subsets of the generator…

Combinatorics · Mathematics 2024-02-16 Martin Otto