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The paper is devoted to a categorical study of the category of probabilistic metric spaces. The study is based on an isomorphic description of the category of probabilistic metric spaces. The isomorphic description was obtained in [3] and…

General Topology · Mathematics 2026-04-02 Eva Colebunders , Robert Lowen

In this paper we define the notions of normal subcrossed module and quotient crossed module within groups with operations; and using the equivalence of crossed modules over groups with operations and internal groupoids we prove how…

Category Theory · Mathematics 2016-01-27 Tunçar Şahan , Osman Mucuk

The combinatorial approach to knot theory treats knots as diagrams modulo Reidemeister moves. Many constructions of knot invariants (e.g., index polynomials, quandle colorings, etc.) use elements of diagrams such as arcs and crossings by…

Geometric Topology · Mathematics 2025-04-29 Igor Nikonov

Given a not necessarily semisimple modular tensor category C, we use the corresponding 3d TFT defined in [arXiv:1912.02063] to explicitly describe a modular functor as a symmetric monoidal 2-functor from a 2-category of oriented bordisms to…

Quantum Algebra · Mathematics 2024-05-29 Aaron Hofer , Ingo Runkel

Multisorted modules, equivalently representations of quivers, equivalently additive functors on preadditive categories, encompass a wide variety of additive structures. In addition, every module has a natural and useful multisorted…

Representation Theory · Mathematics 2018-08-01 Mike Prest

Connections between heaps of modules and (affine) modules over rings are explored. This leads to explicit, often constructive, descriptions of some categorical constructions and properties that are implicit in universal algebra and…

Rings and Algebras · Mathematics 2025-10-08 Simion Breaz , Tomasz Brzezinski , Bernard Rybolowicz , Paolo Saracco

Let $k$ be a commutative $\mathbb{Q}$-algebra. We study families of functors between categories of finitely generated $R$-modules which are defined for all commutative $k$-algebras $R$ simultaneously and are compatible with base changes.…

Category Theory · Mathematics 2020-01-29 Martin Brandenburg

Modular functors are traditionally defined as systems of projective representations of mapping class groups of surfaces that are compatible with gluing. They can formally be described as modular algebras over central extensions of the…

Quantum Algebra · Mathematics 2025-10-27 Adrien Brochier , Lukas Woike

Let k be a commutative ring with unit. We endow the categories of filtered complexes and of bicomplexes of k-modules, with cofibrantly generated model structures, where the class of weak equivalences is given by those morphisms inducing a…

Algebraic Topology · Mathematics 2020-12-09 Joana Cirici , Daniela Egas Santander , Muriel Livernet , Sarah Whitehouse

In this article, we will show that the category of biset functors can be regarded as a reflective monoidal subcategory of the category of Mackey functors on the 2-category of finite groupoids. This reflective subcategory is equivalent to…

Category Theory · Mathematics 2016-01-26 Hiroyuki Nakaoka

This paper is the first in a series of papers in which we define and study a category of "sheaves of $\mathcal Z$-modules on the set of alcoves" that carries important information on the category of representations of semisimple Lie…

Representation Theory · Mathematics 2017-01-16 Peter Fiebig , Martina Lanini

The Hom closed colocalizing subcategories of the stable module category of a finite group are classified. Along the way, the colocalizing subcategories of the homotopy category of injectives over an exterior algebra, and the derived…

Representation Theory · Mathematics 2011-02-15 Dave Benson , Srikanth B. Iyengar , Henning Krause

In this paper we continue the study of triangular matrix categories $\mathbf{\Lambda}=\left[ \begin{smallmatrix} \mathcal{T} & 0 \\ M & \mathcal{U} \end{smallmatrix}\right]$ initiated in [21]. First, given an additive category $\mathcal{C}$…

Category Theory · Mathematics 2019-03-12 Alicia León-Galeana , Martín Ortiz-Morales , Valente Santiago Vargas

We introduce a modified rack algebra Z[X] for racks X with finite rack rank N. We use representations of Z[X] into rings, known as rack modules, to define enhancements of the rack counting invariant for classical and virtual knots and…

Geometric Topology · Mathematics 2010-08-04 Aaron Haas , Garret Heckel , Sam Nelson , Jonah Yuen , Qingcheng Zhang

Crossed squares and 2-crossed modules are both algebraic models for 3-types. This paper explores the interrelationships between these two models.

K-Theory and Homology · Mathematics 2007-05-23 A. Mutlu , T. Porter

We interpret augmented racks as a certain kind of multiplicative graphs and show that this point of view is natural for defining rack homology. We also define the analogue of the group algebra for these objects; in particular, we see how…

Group Theory · Mathematics 2017-08-03 Jacob Mostovoy

In a triangulated category T with a pair of triangulated subcategories X and Y, one may consider the subcategory of extensions X*Y. We give conditions for X*Y to be triangulated and use them to provide tools for constructing stable…

Representation Theory · Mathematics 2015-05-07 Peter Jorgensen , Kiriko Kato

This paper investigates some issues arising in categorical models of reversible logic and computation. Our claim is that the structural (coherence) isomorphisms of these categorical models, although generally overlooked, have decidedly…

Category Theory · Mathematics 2013-04-29 Peter Hines

We study Coxeter racks over $\mathbb{Z}_n$ and the knot and link invariants they define. We exploit the module structure of these racks to enhance the rack counting invariants and give examples showing that these enhanced invariants are…

Geometric Topology · Mathematics 2008-08-13 Sam Nelson , Ryan Wieghard

We describe the structure of module categories of finite dimensional algebras over an algebraically closed field for which the cycles of nonzero nonisomorphisms between indecomposable finite dimensional modules are finite (do not belong to…

Representation Theory · Mathematics 2013-10-24 Piotr Malicki , José A. de la Peña , Andrzej Skowroński