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Related papers: Splitting of homotopy idempotents revisited

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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

We show a Whitney Approximation Theorem for a continuous map from a manifold to a smooth CW complex. This enables us to show that a topological CW complex is homotopy equivalent to a smooth CW complex in a category of topological spaces. It…

Algebraic Topology · Mathematics 2022-08-12 Norio Iwase

We introduce and study the category of twisted modules over a triangular differential graded bocs. We show that in this category idempotents split, that it admits a natural structure of a Frobenius category, that a twisted module is…

Representation Theory · Mathematics 2019-06-25 R. Bautista , E. Pérez , L. Salmerón

In this paper, I prove a splitting theorem for equifocal submanifolds with non-flat section in a simply connected symmetric space of compact type. Also, by using the splitting theorem, I prove that the sections of equifocal submanifolds…

Differential Geometry · Mathematics 2010-02-14 Naoyuki Koike

We show that for a gradable finite dimensional algebra the perfect complexes and bounded derived category cannot be distinguished by homotopy invariants.

K-Theory and Homology · Mathematics 2024-05-10 Sira Gratz , Theo Raedschelders , Špela Špenko , Greg Stevenson

In this paper, we show that the homomorphisms between two unital one-dimensional NCCW complexes with the same KK-class are stably homotopic, i.e., with adding on a common homomorphism (with finite dimensional image), they are homotopic. As…

Operator Algebras · Mathematics 2019-09-18 Qingnan An , George A. Elliott , Zhichao Liu , Yuanhang Zhang

We prove that the group of homotopy classes of relative homotopy automorphisms of a simply connected finite CW-complex is finitely presented and that the rationalization map from this group to its rational analogue has a finite kernel.

Algebraic Topology · Mathematics 2024-02-28 Hadrien Espic , Bashar Saleh

We give a criterion on a group $\pi$ and a homomorphism $w \colon \pi \to C_2$ under which closed $4$-manifolds with fundamental group $\pi$ and orientation character $w$ are classified up to homotopy equivalence by their quadratic…

Geometric Topology · Mathematics 2025-08-12 Jonathan Hillman , Daniel Kasprowski , Mark Powell , Arunima Ray

We study special idempotents (as described by Bushnell and Kutzko) and split idempotents in the context of module and derived categories for idempotented algebras. We then characterize these concepts for path algebras of quivers.

Representation Theory · Mathematics 2018-06-15 Arnab Mitra , Rishi Vyas

This paper is devoted to the study of the separability problem in the field of Quantum information theory. We deal mainly with the bipartite finite dimensional case and with two types of matrices, one of them being the PPT matrices. We…

Quantum Physics · Physics 2016-03-21 Daniel Cariello

Homotopy links have proven to be one of the most powerful tools of stratified homotopy theory. In previous work, we described combinatorial models for the generalized homotopy links of a stratified simplicial set. For many purposes, in…

Algebraic Topology · Mathematics 2025-01-28 Lukas Waas

In this study, we interpret the notion of homotopy of morphisms in the category of crossed modules in a category $\mathsf{C}$ of groups with operations using the categorical equivalence between crossed modules and internal categories in…

Category Theory · Mathematics 2018-11-06 Tunçar Şahan

Given CW complexes X and Y, let map(X,Y) denote the space of continuous functions from X to Y with the compact open topology. The space map(X,Y) need not have the homotopy type of a CW complex. Here the results of an extensive investigation…

Algebraic Topology · Mathematics 2007-08-22 Jaka Smrekar

This is a survey about finite group actions on CW-complexes and related topics, primarily based on our joint work. The main applications are to finite $G$-CW-complexes which are homotopy equivalent to spheres. We have tried to give a fairly…

Algebraic Topology · Mathematics 2026-05-05 Ian Hambleton , Ergun Yalcin

Fiedorowicz suggested that it was likely that every finite simply connected CW complex is homotopy equivalent to the classifying space of a finite semigroup. We prove that every finite wedge of simply connected Moore spaces of finitely…

Group Theory · Mathematics 2025-11-18 Aris Martinian , Benjamin Steinberg

In this paper, using some properties of fundamental groups and covering spaces of connected polyhedra and CW-complexes, we present topological proof for some famous theorems about finitely presented groups.

Algebraic Topology · Mathematics 2010-12-09 Behrooz Mashayekhy , Hanieh Mirebrahimi

In these notes we develop some basic theory of idempotents in monoidal categories. We introduce and study the notion of a pair of complementary idempotents in a triangulated monoidal category, as well as more general idempotent…

Category Theory · Mathematics 2017-03-06 Matthew Hogancamp

The separability tensor element of a separable extension of noncommutative rings is an idempotent when viewed in the correct endomorphism ring; so one speaks of a separability idempotent, as one usually does for separable algebras. It is…

Rings and Algebras · Mathematics 2019-08-30 Lars Kadison

In this paper, we study the notion of a separability idempotent in the C*-algebra framework. This is analogous to the notion in the purely algebraic setting, typically considered in the case of (finite-dimensional) algebras with identity,…

Quantum Algebra · Mathematics 2017-09-26 Byung-Jay Kahng , Alfons Van Daele

We formulate a connection between a topological and a geometric category. The former is the idempotent completion of the (horizontal) trace of the affine Hecke category, while the latter is the equivariant derived category of the…

Geometric Topology · Mathematics 2024-12-10 Eugene Gorsky , Andrei Neguţ