English
Related papers

Related papers: 2-stacks over bisites

200 papers

We define the notion of 2-filtered 2-category and give an explicit construction of the bicolimit of a category valued 2-functor. A category considered as a trivial 2-category is 2-filtered if and only if it is a filtered category, and our…

Category Theory · Mathematics 2021-03-17 Eduardo J. Dubuc , Ross Street

Given a 2-category $\mathcal{A}$, a $2$-functor $\mathcal{A} \overset {F} {\longrightarrow} \mathcal{C}at$ and a distinguished 1-subcategory $\Sigma \subset \mathcal{A}$ containing all the objects, a $\sigma$-cone for $F$ (with respect to…

Category Theory · Mathematics 2018-03-21 M. E. Descotte , E. J. Dubuc , M. Szyld

We develop a 2-dimensional version of accessibility and presentability compatible with the formalism of flat pseudofunctors. First we give prerequisites on the different notions of 2-dimensional colimits, filteredness and cofinality; in…

Category Theory · Mathematics 2025-08-05 Ivan Di Liberti , Axel Osmond

We study (pre-)sheaves in bicategories on geometric categories: smooth manifolds, manifolds with a Lie group action and Lie groupoids. We present three main results: we describe equivariant descent, we generalize the plus construction to…

Algebraic Topology · Mathematics 2011-05-30 Thomas Nikolaus , Christoph Schweigert

The first goal of this survey paper is to argue that if orbifolds are groupoids, then the collection of orbifolds and their maps has to be thought of as a 2-category. Compare this with the classical definition of Satake and Thurston of…

Differential Geometry · Mathematics 2011-04-05 Eugene Lerman

We generalize the notion of a crossed module of groups to that of a crossed module of racks. We investigate the relation to categorified racks, namely strict 2-racks, and trunk-like objects in the category of racks, generalizing the…

Quantum Algebra · Mathematics 2014-04-02 Alissa S. Crans , Friedrich Wagemann

We associate to a bimonoidal functor, i.e. a bifunctor which is monoidal in each variable, a nonabelian version of a biextension. We show that such a biextension satisfies additional triviality conditions which make it a bilinear analog of…

Category Theory · Mathematics 2017-11-15 Ettore Aldrovandi

This document is centered around a main idea: simplicial categories, by which we mean simplicial objects in the category of categories, can be treated as a two-fold categorical structure and their double category theory is homotopically…

Algebraic Topology · Mathematics 2019-08-20 Redi , Haderi

We define a tricategory T of length 3 complexes of abelian sheaves, whose hom-bigroupoids consist of weak morphisms of such complexes. We also define a 3-category 2PIC(S) of Picard 2-stacks, whose hom-2-groupoids consist of additive…

Algebraic Geometry · Mathematics 2014-01-29 A. Emin Tatar

We define bicategories internal to 2-categories. When the ambient 2-category is symmetric monoidal categories, this provides a convenient framework for encoding the structures of a symmetric monoidal 3-category. This framework is well…

Category Theory · Mathematics 2016-11-09 Christopher L. Douglas , André G. Henriques

We define a bicategory $\mathbf{2TDX}$ whose 1-cells provide a categorification of transducers, computational devices extending finite-state automata with output capabilities. This bicategory is a mathematically interesting object: its…

Category Theory · Mathematics 2025-09-11 Fosco Loregian

We provide bicategorical analogs of several aspects of the notion of geometry in the sense of the theory of spectrum. We first introduce a notion of local right biadjoint, and prove it to be equivalent to a notion of bistable pseudofunctor,…

Category Theory · Mathematics 2021-11-19 Axel Osmond

We extend the 2-representation theory of finitary 2-categories to certain 2-categories with infinitely many objects, denoted locally finitary 2-categories, and extend the classical classification results of simple transitive…

Category Theory · Mathematics 2022-01-19 James Macpherson

The familiar trace of a square matrix generalizes to a trace of an endomorphism of a dualizable object in a symmetric monoidal category. To extend these ideas to other settings, such as modules over non-commutative rings, the trace can be…

Category Theory · Mathematics 2024-07-01 Justin Barhite

In this article, we derive many properties of \'etale stacks in various contexts, and prove that \'etale stacks may be characterized categorically as those stacks that arise as prolongations of stacks on a site of spaces and local…

Differential Geometry · Mathematics 2013-06-14 David Carchedi

We define the notion of {\em classifying space} of a topological stack and show that every topological stack \X has a classifying space X which is a topological space well-defined up to weak homotopy equivalence. Under a certain…

Algebraic Topology · Mathematics 2010-05-04 Behrang Noohi

We develop a ready-to-use comprehensive theory for (super) 2-vector bundles over smooth manifolds. It is based on the bicategory of (super) algebras, bimodules, and intertwiners as a model for 2-vector spaces. We discuss symmetric monoidal…

Differential Geometry · Mathematics 2022-09-12 Peter Kristel , Matthias Ludewig , Konrad Waldorf

Many of the properties of sectional category, topological complexity and homotopic distance are in fact derived from a small number of basic properties, which, once established, lead to all the others without further recourse to topology.…

Algebraic Topology · Mathematics 2025-08-26 Jean-Paul Doeraene , Mohammed El Haouari

The sum theorem and its corollaries are proved for a countable family of zero-dimensional (in the sense of small and large inductive bidimensions) p-closed sets, using a new notion of relative normality whose topological correspondent is…

General Topology · Mathematics 2007-06-29 B. P. Dvalishvili

Tightness of a triangulated manifold is a topological condition, roughly meaning that any simplexwise linear embedding of the triangulation into euclidean space is "as convex as possible". It can thus be understood as a generalization of…

Geometric Topology · Mathematics 2011-03-04 Felix Effenberger