English
Related papers

Related papers: Monads need not be endofunctors

200 papers

We prove that the opposite of the category of coalgebras for the Vietoris endofunctor on the category of compact Hausdorff spaces is monadic over Set. We deliver an analogous result for the upper, lower and convex Vietoris endofunctors…

Logic · Mathematics 2025-09-17 Marco Abbadini , Ivan Di Liberti

We prove that there is a monadic adjunction between the category of bounded posets with involution and the category of orthomodular posets.

Rings and Algebras · Mathematics 2022-10-03 Gejza Jenča

This article is devoted to the investigation of the deformation (twisting) of monoidal structures, such as the associativity constraint of the monoidal category and the monoidal structure of monoidal functor. The sets of twistings have a…

q-alg · Mathematics 2008-02-03 A. A. Davydov

We consider the endomorphism operad of a functor, which is roughly the object of natural transformations from (monoidal) powers of that functor to itself. There are many examples from geometry, topology, and algebra where this object has…

Category Theory · Mathematics 2019-07-04 Gabriel C. Drummond-Cole , Joseph Hirsh , Damien Lejay

If T is a commutative monad on a cartesian closed category, then there exists a natural T-bilinear pairing from T(X) times the space of T(1)-valued functions on X ("integration"), as well as a natural T-bilinear action on T(X) by the space…

Category Theory · Mathematics 2011-03-31 Anders Kock

Given a monad $T$ on $\mathscr{A}$ and a functor $G \colon \mathscr{A} \to \mathscr{B}$, one can construct a monad $G_\#T$ on $\mathscr{B}$ subject to the existence of a certain Kan extension; this is the pushforward of $T$ along $G$. We…

Category Theory · Mathematics 2025-01-07 Adrián Doña Mateo

We show how to construct a family of groups with simple commutator subgroups from aperiodic 1-vertex, finitely aligned higher rank graphs (which are, in fact, a class of cancellative monoids). Inverse semigroups form the intermediary…

Rings and Algebras · Mathematics 2020-04-07 Mark V Lawson , Alina Vdovina

The fundamental construction underlying descent theory, the lax descent category, comes with a functor that forgets the descent data. We prove that, in any $2$-category $\mathfrak{A} $ with lax descent objects, the forgetful morphisms…

Category Theory · Mathematics 2021-05-21 Fernando Lucatelli Nunes

Varieties of quantitative algebras are fully described by their free-algebra monads on the category Met of metric spaces. For a longer time it has been an open problem whether the resulting enriched monads are precisely the strongly…

Category Theory · Mathematics 2026-02-06 Jiri Adamek

This paper concerns spherical adjunctions of stable $\infty$-categories and their relation to monadic adjunctions. We begin with a proof of the 2/4 property of spherical adjunctions in the setting of stable $\infty$-categories. The proof is…

Algebraic Topology · Mathematics 2022-08-02 Merlin Christ

We show that the construction due to Leinster and Weber of a generalized Lawvere theory for a familially representable monad on a (co)presheaf category, and the associated ``nerve'' functor from monad algebras to (co)presheaves, have an…

Category Theory · Mathematics 2024-05-24 Brandon T. Shapiro , David I. Spivak

A traced monad is a monad on a traced symmetric monoidal category that lifts the traced symmetric monoidal structure to its Eilenberg-Moore category. A long-standing question has been to provide a characterization of traced monads without…

Category Theory · Mathematics 2024-08-07 Masahito Hasegawa , Jean-Simon Pacaud Lemay

We give an elementary exposition of some fundamental facts about fibered (or rather opfibered) categories, in terms of monads and 2-categories. The account avoids any mention of category-valued functors and pseudofunctors.

Category Theory · Mathematics 2013-12-06 Anders Kock

In this paper we introduce the notion of a relative volutive (higher) category, specializing to the notion of a lax volutive (higher) category. Our primary motivation to study these objects is the following: while any rigid symmetric…

Category Theory · Mathematics 2026-02-18 Tim Lüders

Constructions of spectra from symmetric monoidal categories are typically functorial with respect to strict structure-preserving maps, but often the maps of interest are merely lax monoidal. We describe conditions under which one can…

Algebraic Topology · Mathematics 2017-09-26 Nick Gurski , Niles Johnson , Angélica M. Osorno

We define a notion of grading of a monoid T in a monoidal category C, relative to a class of morphisms M (which provide a notion of M-subobject). We show that, under reasonable conditions (including that M forms a factorization system),…

Logic in Computer Science · Computer Science 2023-08-01 Flavien Breuvart , Dylan McDermott , Tarmo Uustalu

This is a condensed overview of the formal theory of monads in a 2-category. We also define two double categories of monads in a 2-category, extending Lack and Street's 2-categories of monads.

Category Theory · Mathematics 2026-05-06 Aaron David Fairbanks

This paper studies the Eilenberg Moore construction on DG categories. As applications one proves results on factoring of monads as composition of a pair of adjoint exact functors and further applications to reinterpretations of equivariant…

Algebraic Geometry · Mathematics 2018-08-08 Umesh V. Dubey , Vivek Mohan Mallick

Inspired by the classical theory of modules over a monoid, we give a first account of the natural notion of module over a monad. The associated notion of morphism of left modules ("Linear" natural transformations) captures an important…

Logic in Computer Science · Computer Science 2007-05-23 André Hirschowitz , Marco Maggesi

The functor that takes a ring to its category of modules has an adjoint if one remembers the forgetful functor to abelian groups: the endomorphism ring of linear natural transformations. This uses the self-enrichment of the category of…

Category Theory · Mathematics 2020-03-09 Gabriel C. Drummond-Cole , Joseph Hirsh , Damien Lejay