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For a category B with finite products, we first characterize pseudofunctors from B to Cat whose corresponding opfibration is cartesian monoidal. Among those, we then characterize the ones which extend to pseudofunctors from internal groups…

Category Theory · Mathematics 2022-06-03 Alan S. Cigoli , Sandra Mantovani , Giuseppe Metere

We prove that for a bifibration P between small categories, the lenght of the cup product in the kernel of the induced morphism in the Baues-Wirsching cohomology with coefficients in any natural system is a lower bound for the homotopic…

Category Theory · Mathematics 2026-05-19 Isaac Carcacía-Campos , Enrique Macías-Virgós , David Mosquera-Lois

The subject of this paper is a nerve construction for bicategories introduced by Leinster, which defines a fully faithful functor from the category of bicategories and normal pseudofunctors to the category of presheaves over Joyal's…

Category Theory · Mathematics 2020-04-21 Alexander Campbell

We call a finitely complete category algebraically coherent when the change-of-base functors of its fibration of points are coherent, which means that they preserve finite limits and jointly strongly epimorphic pairs of arrows. We give…

Category Theory · Mathematics 2015-12-10 Alan S. Cigoli , James R. A. Gray , Tim Van der Linden

We establish a correspondence between modules and spans of algebras within a general monoidal 2-category $\mathfrak{C}$. Specifically, for an algebra $A$ in $\mathfrak{C}$, we construct a normalized lax 3-functor from the 2-category of…

Category Theory · Mathematics 2025-12-03 Hao Xu

We describe the structure of bimodules (over finite dimensional algebras) which have the property that the functor of tensoring with such a bimodule sends any module to a projective module. The main result is that all such bimodules are…

Representation Theory · Mathematics 2019-06-24 Volodymyr Mazorchuk , Vanessa Miemietz , Xiaoting Zhang

Most categorical models for dependent types have traditionally been heavily set based: contexts form a category, and for each we have a set of types in said context -- and for each type a set of terms of said type. This is the case for…

Logic in Computer Science · Computer Science 2023-12-25 Greta Coraglia , Jacopo Emmenegger

In this paper we study the homotopy theory of parameterized spectrum objects in the $\infty$-category of $(\infty, 2)$-categories, as well as the Quillen cohomology of an $(\infty, 2)$-category with coefficients in such a parameterized…

Algebraic Topology · Mathematics 2018-02-23 Yonatan Harpaz , Joost Nuiten , Matan Prasma

Many structures of interest in two-dimensional category theory have aspects that are inherently strict. This strictness is not a limitation, but rather plays a fundamental role in the theory of such structures. For instance, a monoidal…

Category Theory · Mathematics 2024-12-11 Nathanael Arkor , John Bourke , Joanna Ko

We propose a simplified definition of Quillen's fibration sequences in a pointed model category that fully captures the theory, although it is completely independent of the concept of action. This advantage arises from the understanding…

Algebraic Topology · Mathematics 2021-09-28 Alisa Govzmann , Damjan Pištalo , Norbert Poncin

We show how to treat families of $\infty$-categories fibered in categorical patterns (e.g., $\infty$-operads and monoidal $\infty$-categories) in terms of fibrations by relativizing the Grothendieck construction. As applications, we…

Category Theory · Mathematics 2024-04-02 Kensuke Arakawa

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

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

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

An n-category is some sort of algebraic structure consisting of objects, morphisms between objects, 2-morphisms between morphisms, and so on up to n-morphisms, together with various ways of composing them. We survey various concepts of…

q-alg · Mathematics 2008-02-03 John C. Baez

We attach to each weak model category $\mathcal{M}$ a class of first order formulas about the fibrant objects of $\mathcal{M}$ whose validity is invariant under homotopies and weak equivalences. This is a generalization of the classical…

Category Theory · Mathematics 2025-10-06 César Bardomiano Martínez , Simon Henry

We expand the theory of 2-classifiers, that are a 2-categorical generalization of subobject classifiers introduced by Weber. The idea is to upgrade monomorphisms to discrete opfibrations. We prove that the conditions of 2-classifier can be…

Category Theory · Mathematics 2024-09-19 Luca Mesiti

In this thesis I lift the Curry--Howard--Lambek correspondence between the simply-typed lambda calculus and cartesian closed categories to the bicategorical setting, then use the resulting type theory to prove a coherence result for…

Category Theory · Mathematics 2020-07-02 Philip Saville

We describe a construction that to each algebraically specified notion of higher-dimensional category associates a notion of homomorphism which preserves the categorical structure only up to weakly invertible higher cells. The construction…

Category Theory · Mathematics 2011-10-17 Richard Garner

We clarify the relation between the `bosonisation' construction (due to the author) which can be used to turn a Hopf algebra $B$ in the category of $H$-modules or $H$-comodules into an equivalent ordinary Hopf algebra, and a version of…

q-alg · Mathematics 2008-02-03 S. Majid