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Related papers: Skew-monoidal reflection and lifting theorems

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The skew monoidal categories of Szlach\'anyi are a weakening of monoidal categories where the three structural laws of left and right unitality and associativity are not required to be isomorphisms but merely transformations in a particular…

Logic in Computer Science · Computer Science 2021-01-27 Tarmo Uustalu , Niccolò Veltri , Noam Zeilberger

A non-classical Weyl theory is developed for skew-self-adjoint Dirac systems with rectangular matrix potentials. The notion of the Weyl function is introduced and direct and inverse problems are solved. A Borg-Marchenko type uniqueness…

Classical Analysis and ODEs · Mathematics 2012-11-29 B. Fritzsche , B. Kirstein , I. Ya. Roitberg , A. L. Sakhnovich

In this paper we prove an $\infty$-categorical version of the reflection theorem of Ad\'amek-Rosick\'y. Namely, that a full subcategory of a presentable $\infty$-category which is closed under limits and $\kappa$-filtered colimits is a…

Algebraic Topology · Mathematics 2022-07-20 Shaul Ragimov , Tomer M. Schlank

A subunit in a monoidal category is a subobject of the monoidal unit for which a canonical morphism is invertible. They correspond to open subsets of a base topological space in categories such as those of sheaves or Hilbert modules. We…

Category Theory · Mathematics 2020-06-22 Pau Enrique Moliner , Chris Heunen , Sean Tull

We analyse compatibility between monads and monoidal structures in the two-dimensional setting. We describe sufficient conditions for monoidal structures to lift to the Eilenberg-Moore pseudoalgebras. We then extend these results to braids,…

Category Theory · Mathematics 2024-02-20 Adrian Miranda

Given an action of a monoid $T$ on a ring $A$ by ring endomorphisms, and an Ore subset $S$ of $T$, a general construction of a fractional skew monoid ring $S^{\rm op} * A * T$ is given, extending the usual constructions of skew group rings…

Rings and Algebras · Mathematics 2007-05-23 P. Ara , M. A. Gonzalez-Barroso , K. R. Goodearl , E. Pardo

In this paper, we develop the proof theory of skew prounital closed categories. These are variants of the skew closed categories of Street where the unit is not represented. Skew closed categories in turn are a weakening of the closed…

Logic in Computer Science · Computer Science 2021-01-12 Tarmo Uustalu , Niccolò Veltri , Noam Zeilberger

I motivate a variation (due to K. Szlach\'{a}nyi) of monoidal categories called skew-monoidal categories where the unital and associativity laws are not required to be isomorphisms, only natural transformations. Coherence has to be…

Logic in Computer Science · Computer Science 2014-08-26 Tarmo Uustalu

We show that every braiding on a monoidal bicategory induces a monoidal structure on its bicategory of monoids, such that if the former is sylleptic or symmetric then the latter is braided or symmetric, respectively. This extends a classic…

Category Theory · Mathematics 2026-02-18 Raffael Stenzel

Skew algebroid is a natural generalization of the concept of Lie algebroid. In this paper, for a skew algebroid E, its modular class mod(E) is defined in the classical as well as in the supergeometric formulation. It is proved that there is…

Differential Geometry · Mathematics 2017-01-26 Janusz Grabowski

New formulas on the inverse problem for the continuous skew-self-adjoint Dirac type system are obtained. For the discrete skew-self-adjoint Dirac type system the solution of a general type inverse spectral problem is also derived in terms…

Spectral Theory · Mathematics 2007-05-23 Alexander Sakhnovich

Let $\mathcal{S}$ be a small category, and suppose that we are given a full subcategory $\mathcal{U}$ such that every object of $\mathcal{S}$ can be embedded into some object of $\mathcal{U}$ in the same way as every quasi-projective…

Category Theory · Mathematics 2024-12-12 Luca Terenzi

Motivated by duality phenomena for derived global sections on derived local systems on compact oriented manifolds, we introduce the notion of a $d$-duality context between symmetric monoidal enriched categories. In this setting, the right…

Category Theory · Mathematics 2026-04-02 Valerio Melani , Hugo Pourcelot

We introduce the notion of a braiding on a skew monoidal category, whose curious feature is that the defining isomorphisms involve three objects rather than two. These braidings are shown to arise from, and classify, cobraidings (also known…

Category Theory · Mathematics 2020-01-29 John Bourke , Stephen Lack

We consider algebras and Frobenius algebras, internal to a monoidal category, that are graded over a finite abelian group. For the case that A is a twisted group algebra in a linear abelian monoidal category we obtain a graded…

Quantum Algebra · Mathematics 2025-06-06 Jürgen Fuchs , Tobias Grøsfjeld

This work concerns the proof theory of (left) skew monoidal categories and their variants (e.g. closed monoidal, symmetric monoidal), continuing the line of work initiated in recent years by Uustalu et al. Skew monoidal categories are a…

Logic in Computer Science · Computer Science 2024-04-24 Niccolò Veltri , Cheng-Syuan Wan

Variations on the notions of Reedy model structures and projective model structures on categories of diagrams in a model category are introduced. These allow one to choose only a subset of the entries when defining weak equivalences, or to…

Algebraic Topology · Mathematics 2010-04-23 Mark W. Johnson

We construct a `weak' version EM^w(K) of Lack & Street's 2-category of monads in a 2-category K, by replacing their compatibility constraint of 1-cells with the units of monads by an additional condition on the 2-cells. A relation between…

Category Theory · Mathematics 2012-01-27 Gabriella Böhm

This paper is about skew monoidal tensored V-categories (= skew monoidal hommed V-actegories) and their categories of modules. A module over <M,*,R> is an algebra for the monad T = R * _ on M. We study in detail the skew monoidal structure…

Category Theory · Mathematics 2016-08-30 K. Szlachanyi

It is well known that the category of Gray-categories does not admit a monoidal biclosed structure that models weak higher-dimensional transformations. In this paper, the first of a series on the topic, we describe several skew monoidal…

Category Theory · Mathematics 2023-11-10 John Bourke , Gabriele Lobbia