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Related papers: Coherence for adjunctions in a $4$-category

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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

For every adjunction of stable $\infty$-categories -- or more generally, in any locally stable $(\infty,2)$-category -- we give a simple procedure for inverting the twist and cotwist functors associated to this adjunction. As a consequence,…

Category Theory · Mathematics 2026-05-15 Fernando Abellán , Jonte Gödicke

In the context of infinity categories, we rethink the notion of derived functor in terms of correspondences. This is especially convenient for the description of a passage from an adjoint pair (F,G) of functors to a derived adjoint pair…

Category Theory · Mathematics 2020-03-25 V. Hinich

We propose a new framework for integrating quantifiers with other logical connectives in a higher-categorical setting. Our method systematically incorporates key coherence conditions-including those akin to the Beck-Chevalley property-and…

General Mathematics · Mathematics 2025-05-19 Barreto Joaquim Reizi

The adjunction inequality is a key tool for bounding the genus of smoothly embedded surfaces in 4-manifolds. Using gauge-theoretic invariants, many versions of this inequality have been established for both closed surfaces and surfaces with…

Geometric Topology · Mathematics 2021-07-26 Peter Lambert-Cole

A combinatorial code $\mathcal{C}$ is a collection of subsets of $[n]$, or equivalently a set of points in $\{0,1\}^n$. A morphism of codes is a map from one combinatorial code to another such that the coordinates of points in the image can…

Combinatorics · Mathematics 2026-03-12 Juliann Geraci , Alexander B. Kunin , Alexandra Seceleanu

An n-category is some sort of algebraic structure consisting of objects, morphisms between objects, 2-morphisms between morphisms, and so on up to n-morphisms, together with various ways of composing them. We survey various concepts of…

q-alg · Mathematics 2008-02-03 John C. Baez

Category theory has foundational importance because it provides conceptual lenses to characterize what is important in mathematics. Originally the main lenses were universal mapping properties and natural transformations. In recent decades,…

Category Theory · Mathematics 2007-05-23 David Ellerman

We generalise the usual notion of fibred category; first to fibred 2-categories and then to fibred bicategories. Fibred 2-categories correspond to 2-functors from a 2-category into 2-Cat. Fibred bicategories correspond to trihomomorphisms…

Category Theory · Mathematics 2013-03-26 Mitchell Buckley

Certain results involving "higher structures" are not currently accessible to computer formalization because the prerequisite $\infty$-category theory has not been formalized. To support future work on formalizing $\infty$-category theory…

Category Theory · Mathematics 2025-07-23 Mario Carneiro , Emily Riehl

We prove that a jointly conservative family of geometric functors between rigidly-compactly generated tensor triangulated categories induces a surjective map on Balmer spectra. From this we deduce a fiberwise criterion for Balmer's…

Category Theory · Mathematics 2024-09-27 Tobias Barthel , Natalia Castellana , Drew Heard , Beren Sanders

Graduated locally finitely presentable categories are introduced, examples include categories of sets, vector spaces, posets, presheaves and Boolean algebras. A finitary functor between graduated locally finitely presentable categories is…

Category Theory · Mathematics 2024-02-06 Jirí Adámek , Lurdes Sousa

Coherence is here demonstrated for sesquicartesian categories, which are categories with nonempty finite products and arbitrary finite sums, including the empty sum, where moreover the first and the second projection from the product of the…

Category Theory · Mathematics 2007-05-23 K. Dosen , Z. Petric

We investigate certain adjunctions in derived categories of equivariant spectra, including a right adjoint to fixed points, a right adjoint to pullback by an isometry of universes, and a chain of two right adjoints to geometric fixed…

Algebraic Topology · Mathematics 2018-05-02 Po Hu , Igor Kriz , Petr Somberg

Coherent strings of composable morphisms play an important role in various important constructions in abstract stable homotopy theory (for example algebraic K-theory or higher Toda brackets) and in the representation theory of finite…

Algebraic Topology · Mathematics 2020-01-14 Falk Beckert

Conformal nets are a mathematical model for conformal field theory, and defects between conformal nets are a model for an interaction or phase transition between two conformal field theories. In the preceding paper of this series, we…

Category Theory · Mathematics 2019-05-17 Arthur Bartels , Christopher L. Douglas , André Henriques

Our work over the past years shows that not only the collection of (for instance) all topological spaces gives rise to a category, but also each topological space can be seen individually as a category by interpreting the convergence…

Category Theory · Mathematics 2008-04-03 Dirk Hofmann

This paper aims to answer the following question: Given an adjunction between two categories, how is Quillen (co)homology in one category related to that in the other? We identify the induced comparison diagram, giving necessary and…

Algebraic Topology · Mathematics 2015-05-18 Martin Frankland

We observe that an enriched right adjoint functor between model categories which preserves acyclic fibrations and fibrant objects is quite generically a right Quillen functor.

Algebraic Topology · Mathematics 2024-06-05 Victor Carmona

If a Quillen model category can be specified using a certain logical syntax (intuitively, ``is algebraic/combinatorial enough''), so that it can be defined in any category of sheaves, then the satisfaction of Quillen's axioms over any site…

Category Theory · Mathematics 2009-11-07 Tibor Beke