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Related papers: A comonad for Grothendieck fibrations

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We introduce unary operadic 2-categories as a framework for operadic Grothendieck construction for categorical $\mathbb{O}$-operads, $\mathbb{O}$ being a unary operadic category. The construction is a fully faithful functor…

Category Theory · Mathematics 2024-10-08 Dominik Trnka

We apply the Acyclicity Theorem of Hess, Kerdziorek, Riehl, and Shipley (recently corrected by Garner, Kedziorek, and Riehl) to establishing the existence of model category structure on categories of coalgebras over comonads arising from…

Algebraic Topology · Mathematics 2018-08-15 Kathryn Hess , Magdalena Kedziorek

We show how to "interleave" the monad for operads and the monad for contractions on the category \coll of collections, to construct the monad for the operads-with-contraction of Leinster. We first decompose the adjunction for operads and…

Category Theory · Mathematics 2008-10-06 Eugenia Cheng

Firm Frobenius algebras are firm algebras and counital coalgebras such that the comultiplication is a bimodule map. They are investigated by categorical methods based on a study of adjunctions and lifted functors. Their categories of…

Rings and Algebras · Mathematics 2013-07-18 Gabriella Böhm , José Gómez-Torrecillas

Given an operad $\mathcal{O}$, we define a notion of weak $\mathcal{O}$-monoids -- which we term $\mathcal{O}$-pseudomonoids -- in a 2-category. In the special case with the 2-category in question is the 2-category $\mathsf{Cat}$ of…

Category Theory · Mathematics 2024-04-02 Redi Haderi , Walker H. Stern

The Grothendieck construction establishes an equivalence between fibrations, a.k.a. fibred categories, and indexed categories, and is one of the fundamental results of category theory. Cockett and Cruttwell introduced the notion of…

Category Theory · Mathematics 2025-07-30 Marcello Lanfranchi

This paper is a continuation of ``Operads, Grothendieck topologies and deformation theory'' (alg-geom/9502010). We show how to develop a cohomology theory that would control deformations of a sheaf of associative algebras over a scheme by…

alg-geom · Mathematics 2008-02-03 Dennis Gaitsgory

We construct a model structure on the category $\mathrm{DblCat}$ of double categories and double functors, whose trivial fibrations are the double functors that are surjective on objects, full on horizontal and vertical morphisms, and fully…

Algebraic Topology · Mathematics 2023-06-21 Lyne Moser , Maru Sarazola , Paula Verdugo

In this paper we show that the strict and lax pullbacks of a 2-categorical opfibration along an arbitrary 2-functor are homotopy equivalent. We give two applications. First, we show that the strict fibers of an opfibration model the…

Category Theory · Mathematics 2021-05-18 Nick Gurski , Niles Johnson , Angélica M. Osorno

We give a model-independent construction of directed univalent cocartesian fibrations of $(\infty,1)$-categories, and prove a straightening equivalence against such fibrations. The key step is showing that cocartesian fibrations descend…

Category Theory · Mathematics 2026-03-31 Christian Sattler , David Wärn

Grothendieck fibrations provide a unifying algebraic framework that underlies the treatment of various form of logics, such as first order logic, higher order logics and dependent type theories. In the categorical approach to logic proposed…

Category Theory · Mathematics 2020-09-28 Jacopo Emmenegger , Fabio Pasquali , Giuseppe Rosolini

We present a comonadic approach to pretorsion theories on semiexact categories, i.e. categories equipped with a closed ideal of null morphisms that admits all kernels and all cokernels. We first prove that bihereditary pretorsion theories…

Category Theory · Mathematics 2026-01-19 Elena Caviglia , Zurab Janelidze , Luca Mesiti

For a discrete colored operad $P$, we construct an adjunction between the category of dendroidal sets over the nerve of $P$ and the category of simplicial $P$-algebras, and prove that when $P$ is $\Sigma$-free it establishes a Quillen…

Algebraic Topology · Mathematics 2025-03-17 Francesca Pratali

In this article we describe properties of the 2-functor from the 2-category of comonads to the 2-category of functors that sends a comonad to its forgetful functor. This allows us to describe contexts where algebras over a monad are…

Category Theory · Mathematics 2022-05-04 Brice Le Grignou

We set the foundations of a theory of Grothendieck $(\infty,2)$-topoi based on the notion of fibrational descent, which axiomatizes both the existence of a classifying object for fibrations internal to an $(\infty,2)$-category as well as…

Category Theory · Mathematics 2024-10-04 Fernando Abellán , Louis Martini

Given a hereditary complete cotorsion pair $(\mathsf A,\mathsf B)$ generated by a set of objects in a Grothendieck category $\mathsf K$, we construct a natural equivalence between the Becker coderived category of the left-hand class…

Category Theory · Mathematics 2025-10-14 Leonid Positselski

We generalize to dimension 2 the well-known fact that a colimit in a 1-dimensional slice is precisely the map from the colimit of the domains of the diagram that is induced by the universal property. For this, we find the need to reduce…

Category Theory · Mathematics 2024-12-12 Luca Mesiti

We study lax functors between bicategories as a generalized concept of monads and describe generalized notions and theorems of formal monad theory for lax functors. Our first approach is to use the 2-monad whose lax algebras are lax…

Category Theory · Mathematics 2024-09-20 Kengo Hirata

We categorify cocompleteness results of monad theory, in the context of pseudomonads. We first prove a general result establishing that, in any 2-category, weighted bicolimits can be constructed from oplax bicolimits and bicoequalizers of…

Category Theory · Mathematics 2023-02-15 Axel Osmond

Every Grothendieck fibration gives rise to a vertical/cartesian orthogonal factorization system on its domain. We define a cartesian factorization system to be an orthogonal factorization in which the left class satisfies 2-of-3 and is…

Category Theory · Mathematics 2021-01-22 David Jaz Myers