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Related papers: Kan Extensions in Context of Concreteness

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We give a summary (without proofs) of the main results in the author's thesis entitled ``Construction of biclosed categories'' (University of New South Wales, Australia, 1970). This summary is reprinted directly from Report 81-0030 of the…

Category Theory · Mathematics 2007-05-25 Brian J. Day

Categorical universal algebra can be developed either using Lawvere theories (single-sorted finite product theories) or using monads, and the category of Lawvere theories is equivalent to the category of finitary monads on Set. We show how…

Category Theory · Mathematics 2011-04-14 Stephen Lack , Jiri Rosicky

We develop the theory of relative monads and relative adjunctions in a virtual equipment, extending the theory of monads and adjunctions in a 2-category. The theory of relative comonads and relative coadjunctions follows by duality. While…

Category Theory · Mathematics 2025-10-21 Nathanael Arkor , Dylan McDermott

Category theory is the language of homological algebra, allowing us to state broadly applicable theorems and results without needing to specify the details for every instance of analogous objects. However, authors often stray from the realm…

General Mathematics · Mathematics 2025-02-04 Skyler Marks

Formalized $1$-category theory forms a core component of various libraries of mathematical proofs. However, more sophisticated results in fields from algebraic topology to theoretical physics, where objects have "higher structure," rely on…

Category Theory · Mathematics 2023-12-14 Nikolai Kudasov , Emily Riehl , Jonathan Weinberger

We show that metric abstract elementary classes (mAECs) are, in the sense of [LR] (i.e. arXiv:1404.2528), coherent accessible categories with directed colimits, with concrete $\aleph_1$-directed colimits and concrete monomorphisms. More…

Logic · Mathematics 2017-03-30 Michael Lieberman , Jiri Rosicky

We introduce the notion of Kan injectivity in 2-categories and study its properties. For an adequate 2-category $\mathcal{K}$, we show that every set of morphisms $\mathcal{H}$ induces a KZ-pseudomonad on $\mathcal{K}$ whose 2-category of…

Category Theory · Mathematics 2025-10-16 Ivan Di Liberti , Gabriele Lobbia , Lurdes Sousa

Expansions of abelian categories are introduced. These are certain functors between abelian categories and provide a tool for induction/reduction arguments. Expansions arise naturally in the study of coherent sheaves on weighted projective…

Representation Theory · Mathematics 2010-09-20 Xiao-Wu Chen , Henning Krause

We show that the construction due to Leinster and Weber of a generalized Lawvere theory for a familially representable monad on a (co)presheaf category, and the associated ``nerve'' functor from monad algebras to (co)presheaves, have an…

Category Theory · Mathematics 2024-05-24 Brandon T. Shapiro , David I. Spivak

We introduce and study a purely syntactic notion of lax cones and $(\infty,\infty)$-limits on finite computads in \texttt{CaTT}, a type theory for $(\infty,\infty)$-categories due to Finster and Mimram. Conveniently, finite computads are…

Category Theory · Mathematics 2025-12-01 Thomas Jan Mikhail

In this thesis weighted colimits in 2-categories equipped with promorphisms are studied. Such colimits include most universal constructions with counits, like ordinary colimits in categories, weighted colimits in enriched categories, and…

Category Theory · Mathematics 2013-04-16 Seerp Roald Koudenburg

We develop a general framework for studying signatures, presentations, and algebraic colimits of enriched monads for a subcategory of arities, even when the base of enrichment $\mathcal{V}$ is not locally presentable. When $\mathcal{V}$…

Category Theory · Mathematics 2022-01-11 Rory B. B. Lucyshyn-Wright , Jason Parker

Tangent category theory is a well-established categorical framework for differential geometry. A long list of fundamental geometric constructions, such as the tangent bundle functor, vector fields, Euclidean spaces, and vector bundles have…

Category Theory · Mathematics 2026-01-23 Marcello Lanfranchi

First we develop the theory of local rules for coboundary categories. Then we describe the local rules in two main cases. First for the quantum groups in general and in the seminormal representations of the Hecke algebras. Then for crystals…

Representation Theory · Mathematics 2018-05-10 Bruce W. Westbury

We introduce the notion of algebraic fibrant objects in a general model category and establish a (combinatorial) model category structure on algebraic fibrant objects. Based on this construction we propose algebraic Kan complexes as an…

Algebraic Topology · Mathematics 2011-05-31 Thomas Nikolaus

Ginzburg, Guay, Opdam and Rouquier established an equivalence of categories between a quotient category of the category $\mathcal{O}$ for the rational Cherednik algebra and the category of finite dimension modules of the Hecke algebra of a…

Representation Theory · Mathematics 2022-05-13 Henry Fallet

Additive categories play a fundamental role in mathematics and related disciplines. Given an additive category equipped with a biadditive functor, one can construct its category of extensions, which encodes important structural information.…

Category Theory · Mathematics 2023-10-30 Raphael Bennett-Tennenhaus , Johanne Haugland , Mads Hustad Sandøy , Amit Shah

Each distributor between categories enriched over a small quantaloid Q gives rise to two adjunctions between the categories of contravariant and covariant presheaves, and hence to two monads. These two adjunctions are respectively…

Category Theory · Mathematics 2013-07-23 Lili Shen , Dexue Zhang

Compact categories have lately seen renewed interest via applications to quantum physics. Being essentially finite-dimensional, they cannot accomodate (co)limit-based constructions. For example, they cannot capture protocols such as quantum…

Logic in Computer Science · Computer Science 2016-04-20 Chris Heunen

We generalize the constructions and results of Chapter 10 in Baldwin's "Categoricity" to coherent accessible categories with concrete directed colimits and concrete monomorphisms. In particular, we prove that if any category of this form is…

Logic · Mathematics 2015-05-25 Michael Lieberman , Jiri Rosicky