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Related papers: Nilpotent graphs over skew PBW extensions

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In this paper we compute the center of many noncommutative algebras that can be interpreted as skew $PBW$ extensions. We show that, under some natural assumptions on the parameters that define the extension, either the center is trivial,…

Rings and Algebras · Mathematics 2018-07-18 José Oswaldo Lezama Serrano , Helbert Javier Venegas Ramírez

We answer several open questions and establish new results concerning differential and skew polynomial ring extensions, with emphasis on radicals. In particular, we prove the following results. If $R$ is prime radical and $\delta$ is a…

Rings and Algebras · Mathematics 2018-10-03 Be'eri Greenfeld , Agata Smoktunowicz , Michal Ziembowski

This work investigates the existence of complex structures on 2-step nilpotent Lie algebras arising from finite graphs. We introduce the notion of adapted complex structure, namely a complex structure that maps vertices and edges of the…

Differential Geometry · Mathematics 2025-12-30 Adrián Andrada , Sonia Vera

We study the structure of nilpotent completely positive maps in terms of Choi-Kraus coefficients. We prove several inequalities, including certain majorization type inequalities for dimensions of kernels of powers of nilpotent completely…

Operator Algebras · Mathematics 2013-10-03 B V Rajarama Bhat , Nirupama Mallick

A diagonal base of a Sylow 2-subgroup $P_n(2)$ of symmetric group $S_{2^n}$ is a minimal generating set of this subgroup consisting of elements with only one non-zero coordinate in the polynomial representation. For different diagonal bases…

Group Theory · Mathematics 2018-06-25 Bartłomiej Pawlik

In this work we study the automorphisms of skew $PBW$ extensions and skew quantum polynomials. We use Artamonov's works as reference for getting the principal results about automorphisms for generic skew $PBW$ extensions and generic skew…

Rings and Algebras · Mathematics 2018-06-29 César Fernando Venegas Ramírez , José Oswaldo Lezama Serrano

We investigate and characterize several kinds of elements such as units, idempotents, von Neumann regular, $\pi$-regular and clean elements for skew PBW extensions over weak compatible rings. We also study the notions of Gelfand and…

Rings and Algebras · Mathematics 2022-12-22 Andrés Chacón , Sebastián Higuera , Armando Reyes

Many rings and algebras arising in quantum mechanics, algebraic analysis, and non-commutative algebraic geometry can be interpreted as skew PBW (Poincar\'e-Birkhoff-Witt) extensions. In the present paper we study two aspects of these…

Rings and Algebras · Mathematics 2015-10-13 Oswaldo Lezama , Claudia Gallego

The maximum extensions of finite-dimensional nilpotent Lie algebras are considered. In particular, it is proved that in the general case such an extension is not unique, which refutes one L. Snoble's assumption.

Rings and Algebras · Mathematics 2022-09-09 Vladimir V Gorbatsevich

The classical commutative coding theory has been recently extended to noncommutative rings of polynomial type. There are many interesting works in coding theory over single Ore extensions. In this review article we present the most relevant…

Rings and Algebras · Mathematics 2023-11-01 Oswaldo Lezama , Claudia Gallego

We prove the existence of a limiting distribution for the appropriately rescaled diameters of random undirected Cayley graphs of finite nilpotent groups of bounded rank and nilpotency class, thus extending a result of Shapira and Zuck which…

Combinatorics · Mathematics 2020-02-27 Daniel El-Baz , Carlo Pagano

Let $R$ be a ring and $\sigma$ an endomorphism of $R$. In this note, we study skew polynomial rings and skew power series rings over idempotent reflexive rings and abelian rings. Also, we introduce the concept of right (resp., left)…

Rings and Algebras · Mathematics 2017-11-17 Mohamed Louzari

The unipotent subgroup of a finite group of Lie type over a prime field Z/pZ comes equipped with a natural set of generators; the properties of the Cayley graph associated to this set of generators have been much studied. In the present…

Group Theory · Mathematics 2007-05-23 Jordan S. Ellenberg , Julianna S. Tymoczko

We investigate structural and combinatorial properties of Bi-Cayley graphs defined over cyclic groups of order $p^2q^2$, where $p$ and $q$ are distinct primes. We begin by describing their fundamental group-theoretic underpinnings. The main…

Combinatorics · Mathematics 2026-03-11 Iqbal Atmaja , Yeni Susanti , Ahmad Erfanian

In this paper, we explore the design and analysis of regular bipartite graphs motivated by their application in low-density parity-check (LDPC) codes specifically with constrained girth and in the high-rate regime. We focus on the relation…

Information Theory · Computer Science 2025-06-16 Sheida Rabeti , Mohsen Moradi , Hessam Mahdavifar

In 2015, Dankelmann and Bau proved that for every bridgeless graph $G$ of order $n$ and minimum degree $\delta$ there is an orientation of diameter at most $11\frac{n}{\delta+1}+9$. In 2016, Surmacs reduced this bound to…

Combinatorics · Mathematics 2022-01-20 Garner Cochran

Let (G,w) be a weighted graph. The necessary and sufficient conditions under which a weight w : E(G)-->R^+ can be extended to a pseudoultrametric on V(G) are found. A criterion of the uniqueness of this extension is also obtained. It is…

Metric Geometry · Mathematics 2011-11-01 O. Dovgoshey , E. Petrov

The study of the graph diameter of polytopes is a classical open problem in polyhedral geometry and the theory of linear optimization. In this paper we continue the investigation initiated in [4] by introducing a vast hierarchy of…

Combinatorics · Mathematics 2014-11-27 Steffen Borgwardt , Jesús A. De Loera , Elisabeth Finhold

Motivated by recent extensive studies on Wenger graphs, we introduce a new infinite class of bipartite graphs of the similar type, called linearized Wenger graphs. The spectrum, diameter and girth of these linearized Wenger graphs are…

Combinatorics · Mathematics 2014-12-02 Xiwang Cao , Mei Lu , Daqing Wan , Li-Ping Wang , Qiang Wang

Each group G of nxn permutation matrices has a corresponding permutation polytope, P(G):=conv(G) in R^{nxn}. We relate the structure of P(G) to the transitivity of G. In particular, we show that if G has t nontrivial orbits, then…

Combinatorics · Mathematics 2007-05-23 Robert Guralnick , David Perkinson