English
Related papers

Related papers: Homotopy categories and idempotent completeness, w…

200 papers

We thoroughly treat several familiar and less familiar definitions and results concerning categories, functors and distributors enriched in a base quantaloid Q. In analogy with V-category theory we discuss such things as adjoint functors,…

Category Theory · Mathematics 2007-05-23 Isar Stubbe

We establish rigid tensor category structure on finitely-generated weight modules for the subregular $W$-algebras of $\mathfrak{sl}_n$ at levels $ - n + \frac{n}{n+1}$ (the $\mathcal{B}_{n+1}$-algebras of Creutzig-Ridout-Wood) and at levels…

Quantum Algebra · Mathematics 2024-02-28 Thomas Creutzig , Robert McRae , Jinwei Yang

The homotopy theory of higher categorical structures has become a relevant part of the machinery of algebraic topology and algebraic K-theory, and this paper contains contributions to the study of the relationship between B\'enabou's…

Category Theory · Mathematics 2014-04-11 A. M. Cegarra , B. A. Heredia , J. Remedios

We investigate modules over "systematic" rings. Such rings are "almost graded" and have appeared under various names in the literature; they are special cases of the G-systems of Grzeszczuk. We analyse their K-theory in the presence of…

K-Theory and Homology · Mathematics 2019-09-12 Thomas Huettemann , Zuhong Zhang

Given a fixed tensor triangulated category S we consider triangulated categories T together with an S-enrichment which is compatible with the triangulated structure of T. It is shown that, in this setting, an enriched analogue of Brown…

Category Theory · Mathematics 2016-04-05 Johan Steen , Greg Stevenson

The paper is in essence a survey of categories having $\phi$-weighted colimits for all the weights $\phi$ in some class $\Phi$. We introduce the class $\Phi^+$ of {\em $\Phi$-flat} weights which are those $\psi$ for which $\psi$-colimits…

Category Theory · Mathematics 2007-05-23 G. M. Kelly , V. Schmitt

This note extends Quillen's Theorem A to a large class of categories internal to topological spaces. This allows us to show that under a mild condition a fully faithful and essentially surjective functor between such topological categories…

Algebraic Topology · Mathematics 2024-06-12 David Michael Roberts

We initiate the study of derived functors in the setting of extriangulated categories. By using coends, we adapt Yoneda's theory of higher extensions to this framework. We show that, when there are enough projectives or enough injectives,…

Category Theory · Mathematics 2021-03-24 Mikhail Gorsky , Hiroyuki Nakaoka , Yann Palu

We give a sufficient condition for an Ext-finite triangulated category to be saturated. Saturatedness means that every contravariant cohomological functor of finite type to vector spaces is representable. The condition consists in existence…

Algebraic Geometry · Mathematics 2007-05-23 Alexei Bondal , Michel Van den Bergh

We study t-structures generated by sets of objects which satisfy a condition weaker than the compactness. We also study weight structures cogenerated by sets of objects satisfying the dual condition. Under some appropriate hypothesis, it…

Category Theory · Mathematics 2020-02-05 George Ciprian Modoi

It is known that there is a weak-equivalence between the geometric realization of a simplicially enriched small category and its cofibrant replacement [12]. In this paper, we show that when only small categories are considered there exists…

Algebraic Topology · Mathematics 2019-01-03 Asli Guclukan Ilhan , Ozgun Unlu

In this paper, we classify the homotopy types of the total spaces of $S^{2k-1}$-bundles (or fibrations) over $S^{2k}$ for $2\leq k\leq 6$. One of the two key new ingredients in the argument is the new necessary and sufficient conditions for…

Algebraic Topology · Mathematics 2026-04-17 Zhongjian Zhu , Jianzhong Pan

We show that Klemenc's stable envelope of exact $\infty$-categories induces an equivalence between stable $\infty$-categories with a bounded heart structure and weakly idempotent complete exact $\infty$-categories. Moreover, we generalise…

K-Theory and Homology · Mathematics 2025-12-01 Victor Saunier , Christoph Winges

For every commutative ring $A$, one has a functorial commutative ring $W(A)$ of $p$-typical Witt vectors of $A$, an iterated extension of $A$ by itself. If $A$ is not commutative, it has been known since the pioneering work of L. Hesselholt…

Algebraic Geometry · Mathematics 2017-10-13 D. Kaledin

Let $\mathcal{C}$ be a finitely bicomplete category and $\mathcal{W}$ a subcategory. We prove that the existence of a model structure on $\mathcal{C}$ with $\mathcal{W}$ as subcategory of weak equivalence is not first order expressible.…

Category Theory · Mathematics 2021-02-25 Jean-Marie Droz , Inna Zakharevich

We do three things in this paper: (1) study the analog of localization sequences (in the sense of algebraic $K$-theory of stable $\infty$-categories) for additive $\infty$-categories, (2) define the notion of nilpotent extensions for…

K-Theory and Homology · Mathematics 2021-06-16 Elden Elmanto , Vladimir Sosnilo

We prove that any weakly idempotent complete $d$-exact category is equivalent to a $d$-cluster tilting subcategory of a weakly idempotent complete exact category, and that any weakly idempotent complete algebraic $(d+2)$-angulated category…

Representation Theory · Mathematics 2026-05-26 Sondre Kvamme

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

For a finite dimensional algebra $A$, we prove that the bounded homotopy category of projective $A$-modules and the bounded derived category of $A$-modules are dual to each other via certain categories of locally-finite cohomological…

Rings and Algebras · Mathematics 2018-10-09 Xiao-Wu Chen

Let G denote a compact connected Lie group with torsion-free fundamental group acting on a compact space X such that all the isotropy subgroups are connected subgroups of maximal rank. Let $T\subset G$ be a maximal torus with Weyl group W.…

Algebraic Topology · Mathematics 2014-02-26 Alejandro Adem , José Manuel Gómez