English
Related papers

Related papers: On Whitehead's theorem beyond pointed connected sp…

200 papers

We present a method for computing the classification groups of topological insulators and superconductors in the presence of $\mathbb{Z}_2^{\times n}$ point group symmetries, for arbitrary natural numbers $n$. Each symmetry class is…

Mesoscale and Nanoscale Physics · Physics 2026-03-16 Ken Shiozaki

Cohomology of a topological space with coefficients in stacks of abelian 2-groups is considered. A 2-categorical analog of the theorem of Grothendieck is proved, relating cohomology of the space with coefficients in a 2-stage spectrum and…

Algebraic Topology · Mathematics 2011-06-30 Mamuka Jibladze , Teimuraz Pirashvili

We give a presentation by generators and relations of the group of Clifford+T operators on two qubits. The proof relies on an application of the Reidemeister-Schreier theorem to an earlier result of Greylyn, and has been formally verified…

Quantum Physics · Physics 2023-11-16 Xiaoning Bian , Peter Selinger

Newstead gave the generators of the cohomology ring of the moduli space of rank 2 semi-stable, torsion-free sheaves with fixed odd degree determinant over a smooth, projective curve. In this article, we generalize this result to the case…

Algebraic Geometry · Mathematics 2022-04-19 Suratno Basu , Ananyo Dan , Inder Kaur

We prove the conjecture that any Grothendieck $(\infty,1)$-topos can be presented by a Quillen model category that interprets homotopy type theory with strict univalent universes. Thus, homotopy type theory can be used as a formal language…

Algebraic Topology · Mathematics 2019-04-30 Michael Shulman

We prove coherence theorems for bicategories, pseudofunctors and pseudonatural transformations. These theorems boil down to proving the coherence of some free $(4,2)$-categories. In the case of bicategories and pseudofunctors, existing…

Category Theory · Mathematics 2016-12-21 Maxime Lucas

In Chapter 1 we give the basic background and notations. We also give a new characterization of the Conrad property for orderings. In Chapter 2, we use the new characterization of the Conradian property to give a classification of groups…

Group Theory · Mathematics 2011-03-09 Cristóbal Rivas

The aim of this paper is to generalize some fixed point theorems in the class of convex contraction of order $m$ on a complete suprametric space. Then, we will prove that the class of convex contraction of order m is strong enough to…

General Mathematics · Mathematics 2026-05-11 Nicola Fabiano , Sedigheh Barootkoob , Hossein Lakzian

We give a rather general construction of double categories and so, under further conditions, double groupoids, from a structure we call a `double module'. We also give a homotopical construction of a double groupoid from a triad consisting…

Category Theory · Mathematics 2009-03-21 Ronald Brown

A classification theorem is given of projective threefolds that are covered by a two-dimensional family of lines, but not by a higher dimensional family.

Algebraic Geometry · Mathematics 2007-05-23 Emilia Mezzetti , Dario Portelli

We associate to a 2-vector bundle over an essentially finite groupoid a 2-vector space of parallel sections, or, in representation theoretic terms, of higher invariants, which can be described as homotopy fixed points. Our main result is…

Category Theory · Mathematics 2023-07-03 Christoph Schweigert , Lukas Woike

For a topological space that is homeomorphic to a finite simplicial complex, we prove that the Bartels--Nikolaus assembly functor has a fully faithful right adjoint. Using this, we define for each such topological space $X$ a {\em Whitehead…

Algebraic Topology · Mathematics 2026-04-22 Oscar Harr

We identify a reasonably large class of pushouts of strict $n$-categories which are preserved by the "inclusion" functor from strict $n$-categories to weak $(\infty,n)$-categories. These include the pushouts used to assemble from its…

Category Theory · Mathematics 2023-11-02 Timothy Campion

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 m: G x G -> G has been replaced by a functor. A number of precise definitions of this notion have…

Category Theory · Mathematics 2007-05-23 Aaron D. Lauda

We show that the two models of extensional type theory, those given by the category of equilogical spaces and by the effective topos, are homotopical quotients of categories of 2-groupoids.

Category Theory · Mathematics 2015-12-01 Giuseppe Rosolini

A candidate for the effective 2-topos is proposed and shown to include the effective 1-topos as its subcategory of 0-types.

Category Theory · Mathematics 2026-01-14 Steve Awodey , Jacopo Emmenegger

By a pointed vertex operator algebra (VOA) we mean one whose modules are all simple currents (i.e. invertible), e.g. lattice VOAs. This paper systematically explores the interplay between their orbifolds and tensor category theory. We begin…

Quantum Algebra · Mathematics 2024-10-02 Terry Gannon , Andrew Riesen

In this article, we interconnect two different aspects of higher category theory, in one hand the theory of infinity categories and on an other hand the theory of 2-categories.We construct an explicit functorial path objet in the model…

Algebraic Topology · Mathematics 2012-05-25 Ilias Amrani

In this paper, we will prove that the 2-category (2-SGp) of symmetric 2-groups and 2-category ($\cR$-2-Mod) of $\cR$-2-modules(\cite{5}) have enough projective objects, respectively.

Category Theory · Mathematics 2010-06-25 Fang Huang , Shao-Han Chen , Wei Chen , Zhu-Jun Zheng

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