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We call a ring R pointwise semicommutative if for any element a in R either l(a) or r(a) is an ideal of R. A class of pointwise semicommutative rings is a strict generalization of semicommutative rings. Since reduced rings are pointwise…

Rings and Algebras · Mathematics 2022-06-06 Sanjiv Subba , Tikaram Subedi , A. M. Buhphang

We study the class of rings $R$ for which every direct sum of injective $R$-modules is cotorsion. We call them weakly $\Sigma$-cotorsion rings. The defining property might be seen as the dual of Chase's characterization of coherence in…

Rings and Algebras · Mathematics 2026-02-13 Manuel Cortés-Izurdiaga , Sergio Estrada , José Manuel Fresneda

Let $G$ be a semisimple simply connected complex algebraic group. Let $U$ be the unipotent radical of a Borel subgroup in $G$. We describe the coordinate rings of $U$ (resp., $G/U$, $G$) in terms of two (resp., four, eight) birational…

Representation Theory · Mathematics 2021-02-09 Sergey Fomin , George Lusztig

We provide two new formulations of the separativity problem. First, it is known that separativity (and strong separativity) in von Neumann regular (and exchange) rings is tightly connected to unit-regularity of certain kinds of elements. By…

Rings and Algebras · Mathematics 2024-03-19 Pere Ara , Ken Goodearl , Pace P. Nielsen , Enrique Pardo , Francesc Perera

An integer matrix $\mathbf{A}$ is $\Delta$-modular if the determinant of each $\text{rank}(\mathbf{A}) \times \text{rank}(\mathbf{A})$ submatrix of $\mathbf{A}$ has absolute value at most $\Delta$. The study of $\Delta$-modular matrices…

Optimization and Control · Mathematics 2022-12-08 Joseph Paat , Ingo Stallknecht , Zach Walsh , Luze Xu

We explore elementary matrix reduction over certain rings characterized by their localizations. Let $R$ be a locally stable ring, we prove that $R$ is an elementary divisor ring if and only if $R$ is a Bezout ring. Elementary matrix…

Rings and Algebras · Mathematics 2015-04-21 Marjan Sheibani Abdolyousefi , Huanyin Chen

Let $R$ be a ring with $char(R)\neq2$ whose unit group are denoted by $\mathcal{U}(R)$, $G$ a group, and $RG$ its group ring. Let $*$ be an involution in $G$, $\sigma:G\rightarrow\mathcal{U}(R)$ be a nontrivial group homomorphism, with…

Rings and Algebras · Mathematics 2015-11-24 Edward Landi Tonucci , Thierry Corrêa Petit Lobão

The upper ideal relation graph $\Gamma_{U}(R)$ of a commutative ring $R$ with unity is a simple undirected graph with the set of all non-unit elements of $R$ as a vertex set and two vertices $x$, $y$ are adjacent if and only if the…

Combinatorics · Mathematics 2024-05-30 Mohd Shariq , Praveen Mathil , Jitender Kumar

The m-weak group inverse was recently studied in the literature. The purpose of this paper is to investigate new properties of this generalized inverse for ring elements. We introduce the m-weak group decomposition for a ring element and…

Rings and Algebras · Mathematics 2024-06-25 Huanyin Chen

In this article we introduce the notion of a controlled group graded ring. Let $G$ be a group, with identity element $e$, and let $R=\oplus_{g\in G} R_g$ be a unital $G$-graded ring. We say that $R$ is $G$-controlled if there is a…

Rings and Algebras · Mathematics 2017-01-11 Johan Öinert

In this paper we describe conjugacy classes of a Renner monoid $R$ with unit group $W$, the Weyl group. We show that every element in $R$ is conjugate to an element $ue$ where $u\in W$ and $e$ is an idempotent in a cross section lattice.…

Representation Theory · Mathematics 2012-09-07 Zhuo Li , Zhenheng Li , You'an Cao

In this paper we study invariant rings arising in the study of finite dimensional algebraic structures. The rings we encounter are graded rings of the form $K[U]^{\Gamma}$ where $\Gamma$ is a product of general linear groups over a field…

Representation Theory · Mathematics 2019-07-31 Ehud Meir , with an appendix by Dejan Govc

Let $K$ be a field of characteristic $p>0$, $A=K[[Y]]$ be a power series ring in one variable and $Q(A)$ be the field of fraction of $A$. Suppose that $R=A[X_1,\ldots,X_n]$ is a standard $\mathbb{N}^n$-graded polynomial ring over $A$, i.e.,…

Commutative Algebra · Mathematics 2026-04-10 Sayed Sadiqul Islam

A ring $R$ is called left GF-closed, if the class of all Gorenstein flat left $R$-modules is closed under extensions. The class of left GF-closed rings includes strictly the one of right coherent rings and the one of rings of finite weak…

Commutative Algebra · Mathematics 2008-01-09 D. Bennis

For $n \geq 2$ let $\Delta$ be a Dynkin diagram of rank $n$ and let $I = {1, >..., n}$ be the set of labels of $\Delta$. A group $G$ admits a weak Phan system of type $\Delta$ over $\mathbb{C}$ if $G$ is generated by subgroups $U_i$, $i \in…

Group Theory · Mathematics 2011-08-18 Ralf Köhl

The description of the subgroup structure of a non-commutative division ring is the subject of the intensive study in the theory of division rings in particular, and of the theory of skew linear groups in general. This study is still so far…

Rings and Algebras · Mathematics 2020-11-04 Bui Xuan Hai , Huynh Viet Khanh

Halidon rings are rings with a unit element, containing a primitive $m^{th}$ root of unity and $m$ is invertible in the ring. The field of complex numbers is a halidon ring with any index $ m \geq 1$. In this article, the author examines…

Rings and Algebras · Mathematics 2024-05-20 Antony Telveenus

A ring $R$ satisfies the {\it strong rank condition} (SRC) if, for every natural number $n$, the free $R$-submodules of $R^n$ all have rank $\leq n$. Let $G$ be a group and $R$ a ring strongly graded by $G$ such that the base ring $R_1$ is…

Rings and Algebras · Mathematics 2019-08-16 Peter Kropholler , Karl Lorensen

Let $M$ be a commutative cancellative monoid. The set $\Delta(M)$, which consists of all positive integers which are distances between consecutive factorization lengths of elements in $M$, is a widely studied object in the theory of…

Commutative Algebra · Mathematics 2016-09-12 Scott T. Chapman , Felix Gotti , Roberto Pelayo

Let R be a Noetherian commutative ring of dimension n >2 and let A=R[T,T^{-1}]. Assume that the height of the Jacobson radical of R is atleast 2. Let P be a projective A-module of rank n=dim A - 1 with trivial determinant. We define an…

Commutative Algebra · Mathematics 2011-11-09 Manoj Kumar Keshari