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We consider the canonical pseudodistributive law between various free limit completion pseudomonads and the free coproduct completion pseudomonad. When the class of limits includes pullbacks, we show that this consideration leads to notions…

Category Theory · Mathematics 2024-06-13 Fernando Lucatelli Nunes , Rui Prezado , Matthijs Vákár

Let A be an associative algebra with identity over a field k. An atomistic subsemiring R of the lattice of subspaces of A, endowed with the natural product, is a subsemiring which is a closed atomistic sublattice. When R has no zero…

Rings and Algebras · Mathematics 2017-01-03 Daniel S. Sage

We study conditions under which subdirect products of various types of algebraic structures are finitely generated or finitely presented. In the case of two factors, we prove general results for arbitrary congruence permutable varieties,…

Rings and Algebras · Mathematics 2019-04-24 Peter Mayr , Nik Ruskuc

We exhibit a faithful representation of the stylic monoid of every finite rank as a monoid of upper unitriangular matrices over the tropical semiring. Thus, we show that the stylic monoid of finite rank $n$ generates the pseudovariety…

Rings and Algebras · Mathematics 2022-10-04 Thomas Aird , Duarte Ribeiro

It is shown that the category of semi-biproducts in monoids is equivalent to a category of pseudo-actions. A semi-biproduct in monoids is at the same time a generalization of a semi-direct product in groups and a biproduct in commutative…

Rings and Algebras · Mathematics 2020-02-17 Nelson Martins-Ferreira

We consider an homogeneous action of a finite group on a free linear category over a field in order to prove that the subcategory of invariants is still free. Moreover we show that the representation type is preserved when considering…

Representation Theory · Mathematics 2018-06-12 Claude Cibils , Eduardo N. Marcos

We study polynomial functors over locally cartesian closed categories. After setting up the basic theory, we show how polynomial functors assemble into a double category, in fact a framed bicategory. We show that the free monad on a…

Category Theory · Mathematics 2015-05-13 Nicola Gambino , Joachim Kock

We examine from an invariant theory viewpoint the monoid algebras for two monoids having large symmetry groups. The first monoid is the free left-regular band on $n$ letters, defined on the set of all injective words, that is, the words…

Combinatorics · Mathematics 2025-08-11 Sarah Brauner , Patricia Commins , Victor Reiner

We develop a constructive theory of finite multisets in Homotopy Type Theory, defining them as free commutative monoids. After recalling basic structural properties of the free commutative-monoid construction, we formalise and establish the…

Logic in Computer Science · Computer Science 2023-06-22 Vikraman Choudhury , Marcelo Fiore

Every countable directed graph generates a Fock space Hilbert space and a family of partial isometries. These operators also arise from the left regular representations of free semigroupoids derived from directed graphs. We develop a…

Operator Algebras · Mathematics 2007-05-23 David W. Kribs , Stephen C. Power

We consider monoids equipped with a compatible quantale valued relation, to which we call quantale enriched monoids, and study semidirect products of such structures. It is well-known that semidirect products of monoids are closely related…

Group Theory · Mathematics 2024-06-24 Célia Borlido

We investigate the (separated) monomorphism category $\operatorname{mono}(Q,\Lambda)$ of a quiver $Q$ over an Artin algebra $\Lambda$. We construct an epivalence from $\overline{\operatorname{mono}}(Q,\Lambda)$ to…

Representation Theory · Mathematics 2024-09-09 Nan Gao , Julian Külshammer , Sondre Kvamme , Chrysostomos Psaroudakis

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

Our aim is to bring the theory of analogous polytopes to bear on the study of quasitoric manifolds, in the context of stably complex manifolds with compatible torus action. By way of application, we give an explicit construction of a…

Algebraic Topology · Mathematics 2011-11-09 Victor M. Buchstaber , Taras E. Panov , Nigel Ray

Let $(\mathsf{baxt}_n,~^\sharp)$ be the Baxter monoid of finite rank $n$ with Sch\"{u}tzenberger's involution $^{\sharp}$. In this paper, it is shown that $(\mathsf{baxt}_n,~^\sharp)$ admits a faithful representation by an involution monoid…

Group Theory · Mathematics 2023-02-01 Bin Bin Han , Wen Ting Zhang , Yan Feng Luo , Jin Xing Zhao

Following Mitchell's philosophy, in this paper we define the analogous of the triangular matrix algebra to the context of rings with several objects. Given two additive categories $\mathcal{U}$ and $\mathcal{T}$ and $M\in…

Category Theory · Mathematics 2019-03-12 Alicia León-Galeana , Martín Ortiz-Morales , Valente Santiago Vargas

The main result of this paper is an explicit construction of the free commutative skew brace -- that is, a skew brace whose circle group is commutative -- on an arbitrary generating set $X$. We embed this object into a set of rational…

Group Theory · Mathematics 2025-06-25 Thomas Letourmy

It is shown that the category of \emph{semi-biproducts} of monoids is equivalent to the category of \emph{pseudo-actions}. A semi-biproduct of monoids is a new notion, obtained through generalizing a biproduct of commutative monoids. By…

Category Theory · Mathematics 2021-09-15 Nelson Martins-Ferreira

In this paper, we classify finite categories with two objects such that one of the endomorphism monoids is a group. We prove that having a group on one side affects the structure of the other endomorphism monoid, and we prove that it is…

Category Theory · Mathematics 2022-10-04 Najwa Ghannoum , Carlos Simpson

We introduce a noncommutative binary operation on matroids, called free product. We show that this operation respects matroid duality, and has the property that, given only the cardinalities, an ordered pair of matroids may be recovered, up…

Combinatorics · Mathematics 2007-05-23 Henry Crapo , William Schmitt