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Related papers: Realizable homotopy colimits

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The main objective of this paper is to construct a homotopy colimit functor on a category of functors taking values in the model category of quasi-categories.

Category Theory · Mathematics 2020-07-21 Amit Sharma

We study liftings of abelian model structures to categories of chain complexes and construct a realization functor from the derived category of a Grothendieck abelian category equipped with a cofibrantly generated, hereditary abelian model…

Category Theory · Mathematics 2018-03-12 Hanno Becker

For a small simplicial category A, we prove that the homotopy colimit functor from the category of simplicial diagrams on A to the category of simplicial sets over the homotopy-coherent nerve of A provides a left Quillen equivalence between…

Algebraic Topology · Mathematics 2016-02-04 Gijs Heuts , Ieke Moerdijk

Given an algebraic structure on the homology of a chain complex, we define its realization space as a Kan complex whose vertices are the structures up to homotopy realizing this structure at the homology level. Our algebraic structures are…

Algebraic Topology · Mathematics 2016-11-03 Sinan Yalin

Let $I$ be a small category with finite dimensional nerve, and $X\colon I\to Cat$ a diagram of small categories. We show that, under a "Reedy quasi-fibrancy condition", the homotopy limit of the geometric realization of $X$ is itself the…

Algebraic Topology · Mathematics 2014-10-29 Emanuele Dotto

We give a specific cylinder functor for semifree dg categories. This allows us to construct a homotopy colimit functor explicitly. These two functors are "computable", specifically, the constructed cylinder functor sends a dg category of…

Category Theory · Mathematics 2024-05-07 Dogancan Karabas , Sangjin Lee

We provide a criterion for the existence of right approximations in cocomplete additive categories; it is a straightforward generalisation of a result due to El Bashir. This criterion is used to construct adjoint functors in homotopy…

Category Theory · Mathematics 2010-06-24 Henning Krause

Quillen defined a {\em model category} to be a category with finite limits and colimits carrying a certain extra structure. In this paper, we show that only finite products and coproducts (in addition to the certain extra structure alluded…

Category Theory · Mathematics 2007-05-23 J. M. Egger

This work contributes to clarifying several relationships between certain higher categorical structures and the homotopy types of their classifying spaces. Double categories (Ehresmann, 1963) have well-understood geometric realizations, and…

Algebraic Topology · Mathematics 2010-03-22 Antonio M. Cegarra , Benjamín A. Heredia , Josué Remedios

One way of interpreting a left Kan extension is as taking a kind of "partial colimit", whereby one replaces parts of a diagram by their colimits. We make this intuition precise by means of the "partial evaluations" sitting in the so-called…

Category Theory · Mathematics 2024-04-15 Paolo Perrone , Walter Tholen

In this work, we construct the stable derivator associated to a homotopically complete and cocomplete dg-category by explicitly defining homotopy Kan extensions via suitable weighted homotopy limits and colimits in dg-categories. By…

Category Theory · Mathematics 2025-08-05 Francesco Genovese , Chiara Sava , Jan Šťovíček

In this paper we develop homotopy theoretical methods for studying diagrams. In particular we explain how to construct homotopy colimits and limits in an arbitrary model category. The key concept we introduce is that of a model…

Algebraic Topology · Mathematics 2009-09-25 Wojciech Chacholski , Jerome Scherer

If all objects of a simplicial combinatorial model category \cat A are cofibrant, then there exists the homotopy model structure on the category of small functors $\sS^{\cat A}$, where the fibrant objects are homotopy functors, i.e.,…

Algebraic Topology · Mathematics 2024-07-24 Boris Chorny , David White

Every right adjoint functor between presentable $\infty$-categories is shown to decompose canonically as a coreflection, followed by, possibly transfinitely many, monadic functors. Furthermore, the coreflection part is given a presentation…

Algebraic Topology · Mathematics 2021-11-23 Lior Yanovski

Let $G$ be a finite group acting on a small category $I$. We study functors $X \colon I \to \mathscr{C}$ equipped with families of compatible natural transformations that give a kind of generalized $G$-action on $X$. Such objects are called…

Algebraic Topology · Mathematics 2016-03-09 Emanuele Dotto , Kristian Moi

Model structures for many different kinds of functor calculus can be obtained by applying a theorem of Bousfield to a suitable category of functors. In this paper, we give a general criterion for when model categories obtained via this…

Algebraic Topology · Mathematics 2025-11-05 Lauren Bandklayder , Julia E. Bergner , Rhiannon Griffiths , Brenda Johnson , Rekha Santhanam

We construct combinatorial model category structures on the categories of (marked) categories and (marked) pre-additive categories, and we characterize (marked) additive categories as fibrant objects in a Bousfield localization of…

Algebraic Topology · Mathematics 2021-05-28 Ulrich Bunke , Alexander Engel , Daniel Kasprowski , Christoph Winges

Let $A$ be a virtually Gorenstein algebra of finite CM-type. We establish a duality between the subcategory of compact objects in the homotopy category of Gorenstein projective left $A$-modules and the bounded Gorenstein derived category of…

Representation Theory · Mathematics 2014-02-14 Nan Gao

Many ex/reg completions $J:\mathcal C\to\mathcal C_{\rm ex/reg}$ that arise in categorical realizability and tripos theory admit left Kan extensions of arbitrary finitely continuous functors to arbitrary exact categories. This paper…

Category Theory · Mathematics 2014-02-19 Wouter Pieter Stekelenburg

We introduce the notion of an accessible $\infty$-cosmos and prove that these include the basic examples of $\infty$-cosmoi and are stable under the main constructions. A consequence is that the vast majority of known examples of…

Category Theory · Mathematics 2022-12-14 John Bourke , Stephen Lack