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Related papers: Some properties of the A$_{\infty}$-nerve

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This paper is the second in a series of two papers about generalizing Quillen's Theorem A to strict $\infty$-categories. In the first one, we presented a proof of this Theorem A of a simplicial nature, direct but somewhat ad hoc. In the…

Algebraic Topology · Mathematics 2020-09-07 Dimitri Ara , Georges Maltsiniotis

We show that the Street nerve of a strict $\omega$-category $C$ is a Kan complex (respectively a quasi-category) if and only if the $n$-cells of $C$ for $n\geq 1$ (respectively $n> 1$) are weakly invertible. Moreover, we equip…

Category Theory · Mathematics 2022-07-21 Félix Loubaton

Many definitions of weak n-category have been proposed. It has been widely observed that each of these definitions is of one of two types: algebraic definitions, in which composites and coherence cells are explicitly specified, and…

Category Theory · Mathematics 2014-05-29 Thomas Cottrell

We present a relatively simple description of binary, definable subsets of models of weakly quasi-o-minimal theories. In particular, we closely describe definable linear orders and prove a weak version of the monotonicity theorem. We also…

Logic · Mathematics 2021-06-01 Slavko Moconja , Predrag Tanović

Let A be a commutative ring, and let \a = \frak{a} be a finitely generated ideal in it. It is known that a necessary and sufficient condition for the derived \a-torsion and \a-adic completion functors to be nicely behaved is the weak…

Rings and Algebras · Mathematics 2018-08-08 Rishi Vyas , Amnon Yekutieli

We lay the foundations for a theory of quasi-categories in a monoidal category $\mathcal{V}$ replacing $\mathrm{Set}$, aimed at realising weak enrichment in the category $S\mathcal{V}$ of simplicial objects in $\mathcal{V}$. To accomodate…

Category Theory · Mathematics 2025-05-21 Wendy Lowen , Arne Mertens

In this paper, we define weakly coherent rings, and examine the transfer of these rings to homomorphic image, trivial ring extension, localization, and direct product. These results provide examples of weakly coherent rings that are not…

Commutative Algebra · Mathematics 2010-03-17 Chahrazade Bakkari , Najib Mahdou

Given a locally presentable enriched category $\mathcal{E}$ together with a small dense full subcategory $\mathcal A$ of arities, we study the relationship between monads on $\mathcal E$ and identity-on-objects functors out of $\mathcal A$,…

Category Theory · Mathematics 2020-06-03 John Bourke , Richard Garner

In this paper we construct a symmetric monoidal closed model category of coherently commutative Picard groupoids. We construct another model category structure on the category of (small) permutative categories whose fibrant objects are…

Category Theory · Mathematics 2020-03-13 Amit Sharma

We use type-theoretic techniques to present an algebraic theory of $\infty$-categories with strict units. Starting with a known type-theoretic presentation of fully weak $\infty$-categories, in which terms denote valid operations, we extend…

Logic in Computer Science · Computer Science 2022-05-27 Eric Finster , David Reutter , Alex Rice , Jamie Vicary

This paper explores the relationship amongst the various simplicial and pseudo-simplicial objects characteristically associated to any bicategory C. It proves the fact that the geometric realizations of all of these possible candidate…

Algebraic Topology · Mathematics 2014-10-01 P. Carrasco , A. M. Cegarra , A. R. Garzón

For an abelian category $\mathcal{A}$ we investigate when the stable categories $\underline{\mathrm{GPro}}\mathrm{j}(\mathcal{A})$ and $\underline{\mathrm{GIn}}\mathrm{j}(\mathcal{A})$ are triangulated equivalent. To this end, we realize…

Category Theory · Mathematics 2017-08-10 Georgios Dalezios , Sergio Estrada , Henrik Holm

We introduce the notion of groupoidal (weak) test category, which is a small category A such that the groupoid-valued presheaves over A models homotopy types in a "canonical and nice" way. The definition does not require a priori that A is…

Algebraic Topology · Mathematics 2025-11-05 Léonard Guetta

Given a simplicial group G, there are two known classifying simplicial set constructions, the Kan classifying simplicial set Wbar G and Diag N G, where N denotes the dimensionwise nerve. They are known to be weakly homotopy equivalent. We…

Algebraic Topology · Mathematics 2011-03-31 Sebastian Thomas

We functorially associate to each relative $\infty$-category $(R,W)$ a simplicial space $N^R_\infty(R,W)$, called its Rezk nerve (a straightforward generalization of Rezk's "classification diagram" construction for relative categories). We…

Algebraic Topology · Mathematics 2019-12-25 Aaron Mazel-Gee

We give an intrinsic characterization of the closure under shifts $\widehat{\cal A}$ of a given strictly unital $A_\infty$-category ${\cal A}$. We study some arithmetical properties of its higher operations and special conflations in the…

Representation Theory · Mathematics 2023-10-16 Raymundo Bautista , Efrén Pérez , Leonardo Salmerón

Let $(\mathcal{E}, \mathbb{E}, \mathfrak{s})$ be an extriangulated category. Motivated by the theory of hereditary algebras, we introduce the notion of a hereditary-type subcategory $\mathcal{W}\subseteq \mathcal{E}$. We prove that the…

Representation Theory · Mathematics 2026-05-27 Yu Liu , Yu-Zhe Liu , Panyue Zhou

We propose a categorification of the Dowker duality theorem for relations. Dowker's theorem states that the Dowker complex of a relation $R \subseteq X \times Y$ of sets $X$ and $Y$ is homotopy equivalent to the Dowker complex of the…

Algebraic Topology · Mathematics 2023-03-29 Morten Brun , Marius Gårdsmann Fosse , Lars M. Salbu

We prove properness of (co)Cartesian fibrations as well as a straightening and unstraightening equivalence, which is compatible with cartesian products, when the base is the nerve of a small category.

Category Theory · Mathematics 2022-10-17 Hoang Kim Nguyen

In this paper, we study diffeological spaces as certain kinds of discrete simplicial presheaves on the site of cartesian spaces with the coverage of good open covers. The \v{C}ech model structure on simplicial presheaves provides us with a…

Differential Geometry · Mathematics 2024-04-17 Emilio Minichiello