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Related papers: On fibrant objects in model categories

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We show that the model category of diagrams of spaces generated by a proper class of orbits is not cofibrantly generated. In particular the category of maps between spaces may be given a non-cofibrantly generated model structure.

Algebraic Topology · Mathematics 2013-12-05 Boris Chorny

This is the second paper in a series on representations over diagrams of abelian categories. We show that, under certain conditions, a compatible family of abelian model categories indexed by a skeletal small category can be amalgamated…

Category Theory · Mathematics 2025-06-23 Zhenxing Di , Liping Li , Li Liang , Nina Yu

We use Cisinski's machinery to construct and study model structures on the category of simplicial sets whose classes of fibrant objects generalize quasi-categories. We identify a lifting condition which captures the homotopical behavior of…

Algebraic Topology · Mathematics 2025-04-02 Matthew Feller

In [BaSc2], the author and Tomer Schlank introduced a much weaker homotopical structure than a model category, which we called a "weak cofibration category". We further showed that a small weak cofibration category induces in a natural way…

Algebraic Topology · Mathematics 2016-10-31 Ilan Barnea

The filter quotient construction is a particular instance of a filtered colimit of categories. It has primarily been considered in the context of categorical logic, where it has been used effectively to construct non-trivial models, for…

Category Theory · Mathematics 2026-03-10 Nima Rasekh

We establish that a category of fibrant objects (in the sense of Brown) admits a Dwyer-Kan homotopical calculus of right fractions. This is done using a homotopical calculus of cocycles, which is an auxiliary structure that can be defined…

Category Theory · Mathematics 2015-09-29 Zhen Lin Low

We define local fibration structures for real map germs with strictly positive dimensional discriminant: a local fibration structure over the complement of the discriminant, and a complete local fibration structure which includes the…

Algebraic Geometry · Mathematics 2020-01-06 Maico F. Ribeiro , Raimundo N. Araújo dos Santos , Mihai Tibăr

In [BaSc2] the authors introduced a much weaker homotopical structure than a model category, called a "weak cofibration category". We further showed that a small weak cofibration category induces in a natural way a model category structure…

Algebraic Topology · Mathematics 2016-10-27 Ilan Barnea , Tomer M. Schlank

For a given group $G$ and a collection of subgroups $\mathcal F$ of $G$, we show that there exist a left induced model structure on the category of right $G$-simplicial sets, in which the weak equivalences and cofibrations are the maps that…

Algebraic Topology · Mathematics 2021-02-01 Mehmet Akif Erdal , Aslı Güçlükan İlhan

We prove the existence of a model structure on the category of stratified simplicial sets whose fibrant objects are precisely $n$-complicial sets, which are a proposed model for $(\infty,n)$-categories, based on previous work of Verity and…

Algebraic Topology · Mathematics 2020-06-03 Viktoriya Ozornova , Martina Rovelli

We study Quillen's model category structure for homotopy of simplicial objects in the context of Janelidze, Marki and Tholen's semi-abelian categories. This model structure exists as soon as the base category A is regular Mal'tsev and has…

K-Theory and Homology · Mathematics 2010-06-10 Tim Van der Linden

In this article, we develop a notion of Quillen bifibration which combines the two notions of Grothendieck bifibration and of Quillen model structure. In particular, given a bifibration $p:\mathcal E\to\mathcal B$, we describe when a family…

Category Theory · Mathematics 2017-10-02 Pierre Cagne , Paul-André Melliès

In this note we study the local projective model structure on presheaves of complexes on a site, i.e. we describe its classes of cofibrations, fibrations and weak equivalences. In particular, we prove that the fibrant objects are those…

Category Theory · Mathematics 2020-01-03 Utsav Choudhury , Martin Gallauer

We develop a categorical framework for reasoning about abstract properties of differentiation, based on the theory of fibrations. Our work encompasses the first-order fragments of several existing categorical structures for differentiation,…

Category Theory · Mathematics 2024-09-10 Matteo Capucci , Geoffrey S. H. Cruttwell , Neil Ghani , Fabio Zanasi

We introduce a notion of a filtered model structure and use this notion to produce various model structures on pro-categories. This framework generalizes several known examples. We give several examples, including a homotopy theory for…

Algebraic Topology · Mathematics 2007-05-23 Halvard Fausk , Daniel C. Isaksen

We show that the category of simplicial sets is a co-reflective subcategory of the category of cubical sets with connections, with the inclusion given by a version of the straightening functor. We show that using the co-reflector, one can…

Category Theory · Mathematics 2019-06-24 Chris Kapulkin , Zachery Lindsey , Liang Ze Wong

We prove that the category of directed graphs and graph maps carries a cofibration category structure in which the weak equivalences are the graph maps inducing isomorphisms on path homology.

Combinatorics · Mathematics 2025-12-23 Daniel Carranza , Brandon Doherty , Chris Kapulkin , Morgan Opie , Maru Sarazola , Liang Ze Wong

We prove the well-definedness of some deformations of the fibred biset category in characteristic zero. The method is to realize the fibred biset category and the deformations as the invariant parts of some categories whose compositions are…

Representation Theory · Mathematics 2021-07-27 Laurence Barker , İsmail Alperen Öğüt

Classification questions are often about understanding components of a category. It is much more desirable however to be able to understand the entire homotopy type of this category and not just the set of its components. In this paper we…

Algebraic Topology · Mathematics 2012-06-21 Martin Blomgren , Wojciech Chacholski

We introduce the notion of algebraic fibrant objects in a general model category and establish a (combinatorial) model category structure on algebraic fibrant objects. Based on this construction we propose algebraic Kan complexes as an…

Algebraic Topology · Mathematics 2011-05-31 Thomas Nikolaus