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We give criteria for subcategories of a compactly generated algebraic triangulated category to be precovering or preenveloping. These criteria are formulated in terms of closure conditions involving products, coproducts, directed homotopy…

Representation Theory · Mathematics 2020-07-15 Rosanna Laking , Jorge Vitória

We introduce the notion of a positive opetope and positive opetopic cardinals as certain finite combinatorial structures. The positive opetopic cardinals to positive-to-one polygraphs are like simple graphs to free omega-categories over…

Geometric Topology · Mathematics 2023-04-12 Marek Zawadowski

Strong Steiner $\omega$-categories are a class of $\omega$-categories that admit algebraic models in the form of chain complexes, whose formalism allows for several explicit computations. The conditions defining strong Steiner…

Category Theory · Mathematics 2023-04-05 Dimitri Ara , Andrea Gagna , Viktoriya Ozornova , Martina Rovelli

Categories, n-categories, double categories, and multicategories (among others) all have similar definitions as collections of cells with composition operations. We give an explicit description of the information required to define any…

Category Theory · Mathematics 2025-06-03 Brandon Shapiro

Higher category theory is an exceedingly active area of research, whose rapid growth has been driven by its penetration into a diverse range of scientific fields. Its influence extends through key mathematical disciplines, notably homotopy…

Category Theory · Mathematics 2017-07-07 Simona Paoli

We give a new description of computads for weak globular $\omega$-categories by giving an explicit inductive definition of the free words. This yields a new understanding of computads, and allows a new definition of $\omega$-category that…

Category Theory · Mathematics 2024-11-06 Christopher J. Dean , Eric Finster , Ioannis Markakis , David Reutter , Jamie Vicary

In this paper we introduce the notion of (pointed) prenormal category, modelled after regular categories, but with the key notions of coequaliser and kernel pair replaced by those of cokernel and kernel. This framework provides a natural…

Category Theory · Mathematics 2025-12-29 Sandra Mantovani , Mariano Messora

The semidirect product of a finitely generated group dual with the symmetric group can be described through so-called group-theoretical categories of partitions (covers only a special case; due to Raum--Weber, 2015) and skew categories of…

Quantum Algebra · Mathematics 2022-03-25 Daniel Gromada

In this paper, we introduce a rewriting theory of linear monoidal categories. Those categories are a particular case of what we will define as linear (n, p)-categories. We will also define linear (n, p)-polygraphs, a linear adapation of…

Representation Theory · Mathematics 2016-03-09 Clément Alleaume

We introduce a 3-dimensional categorical structure which we call intercategory. This is a kind of weak triple category with three kinds of arrows, three kinds of 2-dimensional cells and one kind of 3-dimensional cells. In one dimension, the…

Category Theory · Mathematics 2015-09-14 Marco Grandis , Robert Paré

In earlier work, Batanin has shown that an important class of definitions of higher categories could be apprehended together simply as monads over globular sets. This allowed him to generalize the notion of polygraph, initially introduced…

Category Theory · Mathematics 2022-04-06 Simon Forest

Restriction categories were introduced as a way of generalising the notion of partial map categories. In this paper, we define cocomplete restriction category, and give the free cocompletion of a small restriction category as a suitably…

Category Theory · Mathematics 2016-10-25 Richard Garner , Daniel Lin

We introduce a version of skein categories of surfaces which depends on a tensor ideal in a linear ribbon category, thereby extending the existing theory to the setting of non-semisimple TQFTs. We obtain modified notions of skein algebras…

Quantum Algebra · Mathematics 2026-01-29 Jennifer Brown , Benjamin Haïoun

For a collection of subcategories satisfying a fixed set of conditions, for example thick subcategories of a triangulated category, we define a topological space called classifying space of subcategories. We show that this space classifies…

Category Theory · Mathematics 2017-09-12 Yong Liu

We want to replace categories, functors and natural transformations by categories, open functors and open natural transformations. In analogy with open dynamical systems, the adjective open is added here to mean that some external…

Category Theory · Mathematics 2021-02-17 Alexandre Fernandez , Luidnel Maignan , Antoine Spicher

There are a dozen definitions of weak higher categories, all of which loosen the notion of composition of arrows. A new approach is presented here, where instead the notion of identity arrow is weakened -- these are tentatively called fair…

Category Theory · Mathematics 2010-03-09 Joachim Kock

We provide a new approach to categorical graph and hypergraph theory by using categorical syntax and semantics. For each monoid $M$ and action on a set $X$, there is an associated presheaf topos of $(X,M)$-graphs where each object can be…

Combinatorics · Mathematics 2019-07-08 Martin Schmidt

Tree-width is an invaluable tool for computational problems on graphs. But often one would like to compute on other kinds of objects (e.g. decorated graphs or even algebraic structures) where there is no known tree-width analogue. Here we…

Combinatorics · Mathematics 2022-06-22 Benjamin Merlin Bumpus , Zoltan A. Kocsis

Premonoidal and Freyd categories are both generalized by non-cartesian Freyd categories: effectful categories. We construct string diagrams for effectful categories in terms of the string diagrams for a monoidal category with a freely added…

Category Theory · Mathematics 2024-05-03 Mario Román

The concept of n-categories and related subject is considered. An n-category is described as an n-graph with a composition. A new definition of operad is presented. Some illustrative examples are given.

Category Theory · Mathematics 2007-05-23 Zbigniew Oziewicz , Wladyslaw Marcinek