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Related papers: The higher structure of unstable homotopy groups

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Unstable modules over the Steenrod algebra with only the top $k$ operations are introduced in the language of ringoids. We prove the category of such modules has homological dimension at most $k$. A pratical method, which generalizes the…

Algebraic Topology · Mathematics 2022-01-05 Zhulin Li

In this paper we provide an explicit general construction of higher homotopy operations in model categories, which include classical examples such as (long) Toda brackets and (iterated) Massey products, but also cover unpointed operations…

Algebraic Topology · Mathematics 2018-09-21 David Blanc , Mark W. Johnson , James M. Turner

We describe a collection of higher homotopy operations which determine the rational homotopy type of a simply-connected space X. These are described in terms of simplicial resolutions of successive approximations (L^k,\alpha} to the Quillen…

Algebraic Topology · Mathematics 2007-05-23 David Blanc

This is an expository paper providing an overview of the unstable motivic homotopy category using the theory of $(\infty,1)$-categories. In this paper, we examine two constructions in the literature and discuss their equivalence.

Algebraic Topology · Mathematics 2018-10-02 Thomas Brazelton

We show that every sheaf on the site of smooth manifolds with values in a stable (infinity,1)-category (like spectra or chain complexes) gives rise to a differential cohomology diagram and a homotopy formula, which are common features of…

K-Theory and Homology · Mathematics 2013-11-15 Ulrich Bunke , Thomas Nikolaus , Michael Völkl

We give a solution to Dehn's isomorphism problem for the class of all hyperbolic groups, possibly with torsion. We also prove a relative version for groups with peripheral structures. As a corollary, we give a uniform solution to…

Group Theory · Mathematics 2021-04-02 François Dahmani , Vincent Guirardel

We study homotopy properties of regular mappings from spheres into a real retract rational variety $Y$. We show that the homotopy classes which are represented by such mappings form subgroups of the homotopy groups of $Y$, and that the…

Algebraic Geometry · Mathematics 2026-02-16 Juliusz Banecki

In this paper, we show how certain ``stability phenomena'' in unpointed model categories provide the sets of homotopy classes with the structure of abelian heaps, i.e. abelian groups without a choice of a zero. In contrast with the…

Algebraic Topology · Mathematics 2013-12-09 Lukáš Vokřínek

In this paper, we study the structure of homogeneous subgroups of the homeomorphism group of the sphere, which are defined as closed groups of homeomorphisms of the sphere that contain the rotation group. We prove two structure theorems…

Geometric Topology · Mathematics 2015-02-16 Ferry Kwakkel , Fabio Tal

Let G be a rank two finite group, and let $\cH$ denote the family of rank one p-subgroups of G, at all primes where G has p-rank two. We show that a rank two finite group G which satisfies certain group-theoretic conditions admits a finite…

Geometric Topology · Mathematics 2026-04-13 Ian Hambleton , Ergun Yalcin

We prove that the category $\textbf{G-Cat}$ of small categories with $G$-action forms a model of unstable $G$-global homotopy theory for every discrete group $G$, generalizing Schwede's global model structure on $\textbf{Cat}$. As a…

Algebraic Topology · Mathematics 2024-10-03 Tobias Lenz

In this paper, we examine the modal aspects of higher groups in Shulman's Cohesive Homotopy Type Theory. We show that every higher group sits within a modal fracture hexagon which renders it into its discrete, infinitesimal, and…

Category Theory · Mathematics 2025-05-06 David Jaz Myers

We prove that the simplicial complex whose simplices are the nonempty partial bases of $\mathbb{F}_n$ is homotopy equivalent to a wedge of $(n-1)$-spheres. Moreover, we show that it is Cohen-Macaulay.

Algebraic Topology · Mathematics 2020-01-08 Iván Sadofschi Costa

We establish a loop space decomposition for certain $CW$-complexes with a single top cell in the presence of a spherical pair, thereby generalizing several known decompositions of Poincar\'{e} duality complexes in which a loop of a product…

Algebraic Topology · Mathematics 2026-01-06 Ruizhi Huang

The homotopy type of the complement of a complex coordinate subspace arrangement is studied by fathoming out the connection between its topological and combinatorial structures. A family of arrangements for which the complement is homotopy…

Algebraic Topology · Mathematics 2007-05-23 Jelena Grbic , Stephen Theriault

In our previous works, we constructed diffeomorphisms of compact 4-manifolds $X$ by surgeries on theta-graphs embedded in $X$. In this paper, we consider the case $X=M\times I$, where $M$ is a spherical 3-manifold. For some of such $X$, we…

Geometric Topology · Mathematics 2023-10-19 Yuji Ohta , Tadayuki Watanabe

We show that in a weak globular $\omega$-category, all composition operations are equivalent and commutative for cells with sufficiently degenerate boundary, which can be considered a higher-dimensional generalisation of the Eckmann-Hilton…

Category Theory · Mathematics 2025-12-22 Thibaut Benjamin , Ioannis Markakis , Wilfred Offord , Chiara Sarti , Jamie Vicary

We analyze stabilization with respect to ${\mathbb P}^1$ in the Morel--Voevodsky unstable motivic homotopy theory. We introduce a refined notion of cellularity (a.k.a., biconnectivity) in various motivic homotopy categories taking into…

Algebraic Geometry · Mathematics 2026-01-26 Aravind Asok , Tom Bachmann , Michael J. Hopkins

We review the interpretation of Whitehead products in homotopy theory as an entanglement of topological defects in ordered media.

Soft Condensed Matter · Physics 2023-12-04 Gareth P. Alexander , Randall D. Kamien

This paper defines homology in homotopy type theory, in the process stable homotopy groups are also defined. Previous research in synthetic homotopy theory is relied on, in particular the definition of cohomology. This work lays the…

Logic · Mathematics 2018-12-27 Robert Graham