English
Related papers

Related papers: Categories internal to crossed modules

200 papers

We use a result of Barron, Dong and Mason to give a natural isomorphism between the category of twisted modules and the category of quasi-modules of a certain type for a general vertex operator algebra.

Quantum Algebra · Mathematics 2007-05-23 Haisheng Li

We show that the category of corings over a fixed base ring with local units is equivalent to the category of comonads in (right) unital modules whose underlying functors preserve inductive limits. Changing base rings, we prove a…

Rings and Algebras · Mathematics 2009-04-27 L. El Kaoutit

Results on the finiteness of induced crossed modules are proved both algebraically and topologically. Using the Van Kampen type theorem for the fundamental crossed module, applications are given to the 2-types of mapping cones of…

Group Theory · Mathematics 2009-09-25 Ronald Brown , Christopher D. Wensley

We introduce the theory of enrichment over an internal monoidal category as a common generalization of both the standard theories of enriched and internal categories. The aim of the paper is to justify and contextualize the new notion by…

Category Theory · Mathematics 2020-06-16 Enrico Ghiorzi

We extend the notion of the nerve of a category for a small class of crossed simplicial groups, explicitly describing them using generators and relations. We do this by first considering a generalised bar construction of a group before…

Category Theory · Mathematics 2017-05-22 Scott Balchin

Prolongations of a group extension can be studied in a more general situation that we call group extensions of the co-type of a crossed module. Cohomology classification of such extensions is obtained by applying the obstruction theory of…

Category Theory · Mathematics 2015-03-17 Nguyen Tien Quang

We develop a theory of categories which are simultaneously (1) indexed over a base category S with finite products, and (2) enriched over an S-indexed monoidal category V. This includes classical enriched categories, indexed and fibered…

Category Theory · Mathematics 2014-06-10 Michael Shulman

We give a combinatorial model for the bounded derived category of graded modules over the dual numbers in terms of arcs on the integer line with a point at infinity. Using this model we describe the lattice of thick subcategories of the…

Representation Theory · Mathematics 2016-11-08 Sira Gratz , Greg Stevenson

We use the theory of Tambara modules to extend and generalize the reconstruction theorem for module categories over a rigid monoidal category to the non-rigid case. We show a biequivalence between the $2$-category of cyclic module…

Category Theory · Mathematics 2024-08-28 Mateusz Stroiński

We classify certain categories of partitions of finite sets subject to specific rules on the colorization of points and the sizes of blocks. More precisely, we consider pair partitions such that each block contains exactly one white and one…

Combinatorics · Mathematics 2018-09-20 Alexander Mang , Moritz Weber

Neeman shows that the completion of a triangulated category with respect to a good metric yields a triangulated category. We compute completions of discrete cluster categories with respect to metrics induced by internal t-structures. In…

Representation Theory · Mathematics 2024-09-24 Charley Cummings , Sira Gratz

In this paper we present a unified proof of the fact that the category of modules over a ring and the category of near-vector spaces in the sense of J. Andr\'e, over an appropriate scalar system (a 'scalar group'), are both abelian…

Rings and Algebras · Mathematics 2025-01-29 Zurab Janelidze , Sophie Marques , Daniella Moore

We classify semisimple module categories over the tensor category of representations of quantum SL(2) extending previous results to the roots of unity and positive characteristic cases.

Quantum Algebra · Mathematics 2007-05-23 Victor Ostrik

Let A be a commutative unital ring and a an ideal in it. We define and study a-reduced complexes and a-coreduced complexes in both the category of chain complexes of A-modules as well as in the derived category of A-modules. We show that…

Rings and Algebras · Mathematics 2024-04-12 Abebaw Tilahun , Mamo S. Amanuel , Ssevviiri David , Teshome Zelalem

We extend the comatrix coring to the case of a quasi-finite bicomodule. We also generalize some of its interesting properties. We study equivalences between categories of comodules over rather general corings. We particularize to the case…

Rings and Algebras · Mathematics 2007-05-23 Mohssin Zarouali-Darkaoui

We define bicategories internal to 2-categories. When the ambient 2-category is symmetric monoidal categories, this provides a convenient framework for encoding the structures of a symmetric monoidal 3-category. This framework is well…

Category Theory · Mathematics 2016-11-09 Christopher L. Douglas , André G. Henriques

We compare three different ways of defining group cohomology with coefficients in a crossed-module: 1) explicit approach via cocycles; 2) geometric approach via gerbes; 3) group theoretic approach via butterflies. We discuss the case where…

K-Theory and Homology · Mathematics 2010-01-26 Behrang Noohi

We prove a general version of the crystalline equivalence principle which gives an equivalence of categories between a category of TQFTs defined on a generic space with $G$-symmetry, and a category of TQFTs with internal symmetry. We give a…

Mathematical Physics · Physics 2026-01-13 Devon Stockall , Matthew Yu

We show that, with some technical conditions, an abelian category can be embedded into the category of bimodules over a ring. The case of semisimple rigid monoidal categories is studied in more detail.

Category Theory · Mathematics 2007-05-23 Phung Ho Hai

Firstly, we compare the bounded derived categories with respect to the pure-exact and the usual exact structures, and describe bounded derived category by pure-projective modules, under a fairly strong assumption on the ring. Then, we study…

K-Theory and Homology · Mathematics 2020-09-10 Tianya Cao , Wei Ren