English
Related papers

Related papers: On cofinal functors of $\infty$-bicategories

200 papers

We define and discuss lax and weighted colimits of diagrams in $\infty$-categories and show that the coCartesian fibration associated to a functor is given by its lax colimit. A key ingredient, of independent interest, is a simple…

Category Theory · Mathematics 2020-11-03 David Gepner , Rune Haugseng , Thomas Nikolaus

We study four types of (co)cartesian fibrations of $\infty$-bicategories over a given base $\mathcal{B}$, and prove that they encode the four variance flavors of $\mathcal{B}$-indexed diagrams of $\infty$-categories. We then use this…

Algebraic Topology · Mathematics 2021-03-11 Andrea Gagna , Yonatan Harpaz , Edoardo Lanari

We prove a refinement of Quillen's Theorem A, providing necessary and sufficient conditions for a functor to be cofinal with respect to diagrams valued in a fixed $\infty$-category. We deduce this from a general duality phenomenon for…

Category Theory · Mathematics 2025-12-17 Shai Keidar , Lior Yanovski

In the first part of this paper we study fibrations of $(\infty,2)$-categories. We give a simple characterization of such fibrations in terms of a certain square being a pullback, and apply this to show that in some cases…

Category Theory · Mathematics 2026-02-10 Fernando Abellán , Rune Haugseng , Louis Martini

Given a marked $\infty$-category $\mathcal{D}^{\dagger}$ (i.e. an $\infty$-category equipped with a specified collection of morphisms) and a functor $F: \mathcal{D} \to \mathbb{B}$ with values in an $\infty$-bicategory, we define…

Category Theory · Mathematics 2020-10-23 Fernando Abellán García

This paper contains some contributions to the study of the relationship between 2-categories and the homotopy types of their classifying spaces. Mainly, generalizations are given of both Quillen's Theorem B and Thomason's Homotopy Colimit…

Category Theory · Mathematics 2010-03-26 Antonio M. Cegarra

In this work, we prove a generalization of Quillen's Theorem A to 2-categories equipped with a special set of morphisms which we think of as weak equivalences, providing sufficient conditions for a 2-functor to induce an equivalence on…

Algebraic Topology · Mathematics 2020-04-14 Fernando Abellán García , Walker H. Stern

In this paper, we provide a notion of $\infty$-bicategories fibred in $\infty$-bicategories which we call 2-Cartesian fibrations. Our definition is formulated using the language of marked biscaled simplicial sets: Those are scaled…

Algebraic Topology · Mathematics 2021-06-08 Fernando Abellán García , Walker H. Stern

We generalize Quillen's Theorem A to diagrams of lax 2-functors which commute up to transformation. It follows from a special case of this result that 2-categories are models for homotopy types.

Algebraic Topology · Mathematics 2015-02-02 Jonathan Chiche

In this work, we conclude our study of fibred $\infty$-bicategories by providing a Grothendieck construction in this setting. Given a scaled simplicial set $S$ (which need not be fibrant) we construct a 2-categorical version of Lurie's…

Algebraic Topology · Mathematics 2023-04-14 Fernando Abellán , Walker H. Stern

We give the definitions of model bicategory and $q$-homotopy, which are natural generalizations of the notions of model category and homotopy to the context of bicategories. For any model bicategory $\mathcal{C}$, denote by…

Category Theory · Mathematics 2022-05-06 M. E. Descotte , E. J. Dubuc , M. Szyld

We generalise the usual notion of fibred category; first to fibred 2-categories and then to fibred bicategories. Fibred 2-categories correspond to 2-functors from a 2-category into 2-Cat. Fibred bicategories correspond to trihomomorphisms…

Category Theory · Mathematics 2013-03-26 Mitchell Buckley

In this work we provide a model-independent notion of local fibrations of $(\infty,2)$-categories which generalises the well-known theory of locally coCartesian fibrations of $(\infty,1)$-categories. Based on previous work, we construct a…

Algebraic Topology · Mathematics 2023-05-03 F. Abellán

We prove that a (lax) bilimit of a 2-functor is characterized by the existence of a limiting contraction in the 2-category of (lax) cones over the diagram. We also investigate the notion of bifinal object and prove that a (lax) bilimit is a…

Category Theory · Mathematics 2022-04-27 Andrea Gagna , Yonatan Harpaz , Edoardo Lanari

The main result concerns a bicategorical factorization system on the bicategory $\mathrm{Cat}$ of categories and functors. Each functor $A\xra{f} B$ factors up to isomorphism as $A\xra{j}E\xra{p}B$ where $j$ is what we call an ultimate…

Category Theory · Mathematics 2021-04-08 Ross Street

We prove a bicategorical analogue of Quillen's Theorem A. As an application, we deduce the well-known result that a pseudofunctor is a biequivalence if and only if it is essentially surjective on objects, essentially full on 1-cells, and…

Category Theory · Mathematics 2021-12-21 Niles Johnson , Donald Yau

We show that the conditions in Steimle's 'additivity theorem for cobordism categories' can be weakened to only require \emph{locally} (co)Cartesian fibrations, making it applicable to a larger class of functors. As an application we compute…

Algebraic Topology · Mathematics 2022-09-05 Jan Steinebrunner

The contributions of this paper are twofold. Within the framework of Grothendieck's fibrational category theory, we present a web of fundamental 2-adjunctions surrounding the formation of the category of all small diagrams in a given…

Category Theory · Mathematics 2021-03-09 George Peschke , Walter Tholen

We study the interaction between the notions of filteredness, fractions and fibrations in the theory of bicategories, generalizing classical results for categories. We give an explicit formula for filtered pseudo-colimits of categories…

Category Theory · Mathematics 2021-12-02 P. Bustillo Vazquez , D. Pronk , M. Szyld

We investigate the connection between left exact $\infty$-functors between finitely complete quasicategories and exact functors between fibration categories, describing a procedure to approximate flat $\infty$-functors of the former type by…

Category Theory · Mathematics 2026-02-20 El Mehdi Cherradi
‹ Prev 1 2 3 10 Next ›