English
Related papers

Related papers: On partial skew groupoids rings

200 papers

A flag manifold over a semifield K can be partitioned into "half i-circles" which are orbits of a K-action on that flag manifold. Here i is fixed and it corresponds to a simple reflection in the Weyl group. We prove (for certain K) a…

Representation Theory · Mathematics 2022-12-21 G. Lusztig

Sufficient conditions for a semigroup measure algebra to have contractible Gelfand spectrum are given and it is shown that for a wide class of semigroups these conditions are also necessary.

Functional Analysis · Mathematics 2019-03-08 A. R. Mirotin

In this paper, we construct a partial group \(\mathcal{P}(F)\) that represents the "partial symmetry" inherent in a subset \(F\) of \(d\)-dimensional Euclidean space. In cases where \(F\) is not connected, \(\mathcal{P}(F)\) captures more…

Group Theory · Mathematics 2025-08-27 Takahiro Hayashi

We introduce the concept of a partial abstract kernel associated to a group G and a semilattice of groups A and relate the partial cohomology group H^3(G,C(A)) with the obstructions to the existence of admissible extensions of A by G which…

Group Theory · Mathematics 2020-02-12 Mikhailo Dokuchaev , Mykola Khrypchenko , Mayumi Makuta

We consider a version of the notion of F-inverse semigroup (studied in the algebraic theory of inverse semigroups). We point out that an action of such an inverse semigroup on a locally compact space has associated a natural groupoid…

funct-an · Mathematics 2008-02-03 Alexandru Nica

Let $G$ be a finite solvable group and $H$ be a subgroup of $Aut(G)$. Suppose that there exists an $H$-invariant Carter subgroup $F$ of $G$ such that the semidirect product $FH$ is a Frobenius group with kernel $F$. We prove that the terms…

Group Theory · Mathematics 2019-07-26 Gülin Ercan , İsmail Ş. Güloğlu

A magmoid is a non-empty set with a partial binary operation; group-like magmoids generalize group-like magmas such as semigroups, monoids and groups. In this article, we first consider the many ways in which the notions of associative…

Group Theory · Mathematics 2019-05-07 Dan Jonsson

Consider a commutative monoid $(M,+,0)$ and a biadditive binary operation $\mu \colon M \times M \to M$. We will show that under some additional general assumptions, the operation $\mu$ is automatically both associative and commutative. The…

Rings and Algebras · Mathematics 2024-06-18 Matthias Schötz

We consider skew free extensions of rings, also known as free multivariate skew polynomial rings, and explore some of the algebraic aspects of this construction. We give different characterizations of such rings and present conditions for…

Rings and Algebras · Mathematics 2025-03-03 Vitor O. Ferreira , Érica Z. Fornaroli , Javier Sánchez

Given a group G, a (unital) ring A and a group homomorphism $\sigma : G \to \Aut(A)$, one can construct the skew group ring $A \rtimes_{\sigma} G$. We show that a skew group ring $A \rtimes_{\sigma} G$, of an abelian group G, is simple if…

Rings and Algebras · Mathematics 2014-02-17 Johan Öinert

In this work, we introduce the notion of a partial action of a group on a strict monoidal category. We propose, in the context of Monoidal categories, new constructions analogous to those existing for partial group actions over an algebra…

Category Theory · Mathematics 2024-12-18 Eliezer Batista , Felipe Lopes Castro , Mykola Khrypchenko

Let $A\subseteq B$ be a ring extension and $\mathcal{G}$ be a set of $A$-submodules of $B$. We introduce a class of closure operations on $\mathcal{G}$ (which we call \emph{multiplicative operations on $(A,B,\mathcal{G})$}) that generalizes…

Commutative Algebra · Mathematics 2019-10-31 Dario Spirito

We realize Leavitt ultragraph path algebras as partial skew group rings. Using this realization we characterize artinian ultragraph path algebras and give simplicity criteria for these algebras.

Rings and Algebras · Mathematics 2017-06-14 Daniel Gonçalves , Danilo Royer

We study statistical properties of random numerical semigroups of a given genus. We analyze the graph of a typical numerical semigroup, understood as a function from $\mathbb{N}$ to $\mathbb{N}$. If $S$ is a numerical semigroup of genus…

Combinatorics · Mathematics 2026-04-30 Maria Bras-Amorós , Nathan Kaplan , Deepesh Singhal

The main goal of this note is to suggest an algebraic approach to the quasi-isometric classification of partially commutative groups (alias right-angled Artin groups). More precisely, we conjecture that if the partially commutative groups…

Group Theory · Mathematics 2018-03-02 Montserrat Casals-Ruiz

Through this work we introduce an action of the skew polynomial ring $\mathbb{F}_{q}\left[X; \sigma, \delta\right]$ over $\mathbb{F}_{q}$ based on its polynomial valuation and the concept of left skew product of functions. This lead us to…

Cryptography and Security · Computer Science 2025-12-03 Daniel Camazón-Portela , Juan Antonio López-Ramos

In this work, the notion of a twisted partial Hopf action is introduced as a unified approach for twisted partial group actions, partial Hopf actions and twisted actions of Hopf algebras. The conditions on partial cocycles are established…

Rings and Algebras · Mathematics 2015-11-12 Marcelo Muniz S. Alves , Eliezer Batista , Michael Dokuchaev , Antonio Paques

Let $M$ be a monoid, $\mathscr{C}$ a category with pullbacks and $X$ an object of $\mathscr{C}$. We introduce the notion of a partial action $\alpha$ of $M$ on $X$ and study the globalization question for $\alpha$. If $\alpha$ admits a…

Category Theory · Mathematics 2026-02-05 Mykola Khrypchenko , Francisco Klock

We develop a cohomology theory of groups based on partial actions and explore its relation with the partial Schur multiplier as well as with cohomology of inverse semigroups.

Group Theory · Mathematics 2018-02-02 M. Dokuchaev , M. Khrypchenko

The purpose of this note is to relate certain ring-theoretic properties of rings in mixed and positive characteristics that are related to each other by a tilting operation used in perfectoid geometry. To this aim, we exploit the…

Commutative Algebra · Mathematics 2026-01-05 Kazufumi Eto , Jun Horiuchi , Kazuma Shimomoto