English
Related papers

Related papers: Double groupoids and homotopy 2-types

200 papers

Let $f:G\rightarrow H$ be a homomorphism of groups, we construct a topological space $X_f$ such that its group of homeomorphisms is isomorphic to $G$, its group of homotopy classes of self-homotopy equivalences is isomorphic to $H$ and the…

Algebraic Topology · Mathematics 2021-04-16 Pedro J. Chocano , Manuel A. Morón , Francisco R. Ruiz del Portal

We introduce the notion of a symplectic hopfoid, which is a "groupoid-like" object in the category of symplectic manifolds where morphisms are given by canonical relations. Such groupoid-like objects arise when applying a version of the…

Differential Geometry · Mathematics 2017-12-20 Santiago Canez

This paper is the second in a series exploring the properties of a functor which assigns a homotopy double groupoid with connections to a Hausdorff space. We show that this functor satisfies a version of the van Kampen theorem, and so is a…

Algebraic Topology · Mathematics 2007-05-23 R. Brown , H. K. Kamps , T. Porter

One of the prime motivation for topology was Homotopy theory, which captures the general idea of a continuous transformation between two entities, which may be spaces or maps. In later decades, an algebraic formulation of topology was…

Category Theory · Mathematics 2025-11-24 Suddhasattwa Das

We investigate algebraic and compositional properties of abstract multiway rewriting systems, which are archetypical structures underlying the formalism of the Wolfram model. We demonstrate the existence of higher homotopies in this class…

Category Theory · Mathematics 2021-11-29 Xerxes D. Arsiwalla , Jonathan Gorard , Hatem Elshatlawy

Building on work by Fiore-Pronk-Paoli, we construct four model structures on the category of double categories, each modeling one of the following: simplicial spaces, Segal spaces, $(\infty,1)$-categories, and $\infty$-groupoids.…

Algebraic Topology · Mathematics 2024-12-23 Léonard Guetta , Lyne Moser

We investigate topological realizations of higher-rank graphs. We show that the fundamental group of a higher-rank graph coincides with the fundamental group of its topological realization. We also show that topological realization of…

Combinatorics · Mathematics 2012-05-15 S. Kaliszewski , Alex Kumjian , John Quigg , Aidan Sims

We introduce and study a notion of cylinder coherator similar to the notion of Grothendieck coherator which define more flexible notion of weak infinity groupoids. We show that each such cylinder coherator produces a combinatorial…

Category Theory · Mathematics 2016-09-16 Simon Henry

Given a topological group G, its orbit category Orb_G has the transitive G-spaces G/H as objects and the G-equivariant maps between them as morphisms. A well known theorem of Elmendorf then states that the category of G-spaces and the…

Algebraic Topology · Mathematics 2007-05-23 Andre Henriques , David Gepner

To a bicomplex one can associate two natural filtrations, the column and row filtrations, and then two associated spectral sequences. This can be generalized to $N$-multicomplexes. We present a family of model category structures on the…

Algebraic Topology · Mathematics 2025-11-11 Joana Cirici , Muriel Livernet , Sarah Whitehouse

We define and study homotopy groups of cubical sets. To this end, we give four definitions of homotopy groups of a cubical set, prove that they are equivalent, and further that they agree with their topological analogues via the geometric…

Algebraic Topology · Mathematics 2025-12-23 Daniel Carranza , Chris Kapulkin

A 2-group is a "categorified" version of a group, in which the underlying set G has been replaced by a category and the multiplication map has been replaced by a functor. Various versions of this notion have already been explored; our goal…

Quantum Algebra · Mathematics 2007-05-23 John C. Baez , Aaron D. Lauda

This paper gives a uniform-theoretic refinement of classical homotopy theory. Both cubical sets (with connections) and uniform spaces admit classes of weak equivalences, special cases of classical weak equivalences, appropriate for the…

Algebraic Topology · Mathematics 2021-09-20 Sanjeevi Krishnan , Crichton Ogle

Given a group $G$, we define suitable 2-categorical structures on the class of all small categories with $G$-actions and on the class of all small $G$-graded categories, and prove that 2-categorical extensions of the orbit category…

Category Theory · Mathematics 2015-11-02 Hideto Asashiba

It is well-known that small categories have equivalent descriptions as partial monoids. We provide a formulation of partial monoid and partial monoid homomorphism involving $s$ and $t$ instead of identities and then following a recent…

Category Theory · Mathematics 2015-03-02 Rachel A. D. Martins

The category of double categories and double functors is equipped with a symmetric closed monoidal structure. For any double category $\mathbb A$, the corresponding internal hom functor $|[ \mathbb A,-]|$ sends a double category $\mathbb B$…

Category Theory · Mathematics 2019-01-31 Gabriella Böhm

We show that the topological full group of a Hausdorff ample groupoid with compact unit space coincides with the group of homotopy classes of invertible isometries in pseudofunction algebras associated with the groupoid. Moreover, if the…

Operator Algebras · Mathematics 2025-11-19 Eusebio Gardella , Mathias Palmstrøm , Hannes Thiel

The Grothendieck groups of the categories of finitely generated modules and finitely generated projective modules over a tower of algebras can be endowed with (co)algebra structures that, in many cases of interest, give rise to a dual pair…

Representation Theory · Mathematics 2014-10-24 Alistair Savage , Oded Yacobi

Polynomial functors are a categorical generalization of the usual notion of polynomial, which has found many applications in higher categories and type theory: those are generated by polynomials consisting a set of monomials built from sets…

Logic in Computer Science · Computer Science 2021-12-30 Eric Finster , Samuel Mimram , Maxime Lucas , Thomas Seiller

Modular functors, i.e. consistent systems of projective representations of mapping class groups of surfaces, have been constructed for non-semisimple modular categories already decades ago. Concepts from homological algebra have not been…

Quantum Algebra · Mathematics 2022-01-07 Christoph Schweigert , Lukas Woike