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We show that differential calculus (in its usual form, or in the general form of topological differential calculus) can be fully imdedded into a functor category (functors from a small category of anchord tangent algebras to anchored sets).…

Algebraic Geometry · Mathematics 2021-03-25 Wolfgang Bertram , Jérémy Haut

In this paper, we address the construction of homotopy bicategories of $(\infty,2)$-categories, which we take as being modeled by 2-fold Segal spaces. Our main result is the concrete construction of a functor $h_2$ from the category of…

Category Theory · Mathematics 2025-02-14 Jack Romö

We give an explicit handy (and cocycle-free) description of the groupoid of weak maps between two crossed-modules in terms of certain digrams of groups which we we call a {\em butterflies}. We define composition of butterflies and this way…

Category Theory · Mathematics 2008-07-13 Behrang Noohi

In his paper "Th\'eories homotopiques des 2-cat\'egories", Jonathan Chiche studies homotopy theories on 2-Cat, the category of small strict 2-categories, given by classes of weak equivalences which he calls basic localizers of 2-Cat. These…

Algebraic Topology · Mathematics 2020-09-07 Dimitri Ara

Throughout this paper $G$ is a fixed group, and $k$ is a fixed field. All categories are assumed to be $k$-linear. First we give a systematic way to induce $G$-precoverings by adjoint functors using a 2-categorical machinery, which unifies…

Representation Theory · Mathematics 2024-02-08 Rasool Hafezi , Hideto Asashiba , Mohammad Hossein Keshavarz

Using full images of accessible functors, we prove some results about combinatorial and accessible model categories. In particular, we give an example of a weak factorization system on a locally presentable category which is not accessible.

Category Theory · Mathematics 2022-02-08 Jiří Rosický

This article is first in a series of papers where we reprove the statements in constructing the Enhanced Operation Map and the abstract six-functor formalism developed by Liu-Zheng. In this paper, we prove a theorem regarding constructing…

Algebraic Geometry · Mathematics 2025-01-28 Chirantan Chowdhury

Given a functor $T:C \to D$ carrying a class of morphisms $S\subset C$ into a class $S'\subset D$, we give sufficient conditions in order that $T$ induces an equivalence on the localised categories. These conditions are in the spirit of…

Algebraic Geometry · Mathematics 2010-09-13 Bruno Kahn , R. Sujatha

We consider $(\infty,d)$-categories in the limit $d\to \infty$ via the core or localization functors that forget or invert higher non-invertible arrows, respectively. We compare the two resulting $(\infty,1)$-categories of…

Algebraic Topology · Mathematics 2026-03-12 Viktoriya Ozornova , Martina Rovelli , Tashi Walde

We prove that the 2-category Grt of Grothendieck abelian categories with colimit preserving functors and natural transformations is a bicategory of fractions in the sense of Pronk of the 2-category Site of linear sites with continuous…

Category Theory · Mathematics 2018-01-15 Julia Ramos González

In some bicategories, the 1-cells are `morphisms' between the 0-cells, such as functors between categories, but in others they are `objects' over the 0-cells, such as bimodules, spans, distributors, or parametrized spectra. Many…

Category Theory · Mathematics 2010-03-15 Michael A. Shulman

We fix any bicategory $\mathscr{A}$ together with a class of morphisms $\mathbf{W}_{\mathscr{A}}$, such that there is a bicategory of fractions $\mathscr{A}[\mathbf{W}_{\mathscr{A}}^{-1}]$. Given another such pair…

Category Theory · Mathematics 2014-11-24 Matteo Tommasini

Category theory unifies mathematical concepts, aiding comparisons across structures by incorporating objects and morphisms, which capture their interactions. It has influenced areas of computer science such as automata theory, functional…

Category Theory · Mathematics 2024-02-09 Nima Rasekh , Niels van der Weide , Benedikt Ahrens , Paige Randall North

We study bicategories of (deterministic) automata, drawing from prior work of Katis-Sabadini-Walters, and Di Lavore-Gianola-Rom\'an-Sabadini-Soboci\'nski, and linking their bicategories of `processes' to a bicategory of Mealy machines…

Category Theory · Mathematics 2023-12-15 Guido Boccali , Andrea Laretto , Fosco Loregian , Stefano Luneia

A subunit in a monoidal category is a subobject of the monoidal unit for which a canonical morphism is invertible. They correspond to open subsets of a base topological space in categories such as those of sheaves or Hilbert modules. We…

Category Theory · Mathematics 2020-06-22 Pau Enrique Moliner , Chris Heunen , Sean Tull

In this paper, we present new concepts of Ann-categories, Ann-functors, and a transmission of the structure of categories based on Ann-equivalences. We build Ann-category of Pic-funtors and prove that each Ann-category can be faithfully…

Category Theory · Mathematics 2007-05-23 Tien Quang Nguyen

The bicategorical point of view provides a natural setting for many concepts in the representation theory of monoidal categories. We show that centers of twisted bimodule categories correspond to categories of 2-dimensional natural…

Category Theory · Mathematics 2023-06-09 Bojana Femić , Sebastian Halbig

For a given category C and a topological space X, the constant stack on X with stalk C is the stack of locally constant sheaves with values in C. Its global objects are classified by their monodromy, a functor from the Poincare groupoid of…

Algebraic Topology · Mathematics 2007-05-23 Pietro Polesello , Ingo Waschkies

This paper emerged as a result of tackling the following three issues. Firstly, we would like the well known embedding of bicategories into pseudo double categories to be monoidal, which it is not if one uses the usual notion of a monoidal…

Category Theory · Mathematics 2021-06-02 Bojana Femić

Abstract inner automorphisms can be used to promote any category into a 2-category, and we study two-dimensional limits and colimits in the resulting 2-categories. Existing connected colimits and limits in the starting category become…

Category Theory · Mathematics 2025-09-08 Pieter Hofstra , Martti Karvonen