On diameter of the zero-divisor and the compressed zero-divisor graphs of skew Laurent polynomial rings

2019 ◽  
Vol 18 (07) ◽  
pp. 1950126 ◽  
Author(s):  
Ebrahim Hashemi ◽  
Mona Abdi ◽  
Abdollah Alhevaz
Keyword(s):  
Zero Divisor ◽  
Undirected Graph ◽  
Complete Characterization ◽  
Laurent Polynomial ◽  
Polynomial Rings ◽  
Noncommutative Rings ◽  
Zero Divisor Graph ◽  
Zero Divisors ◽  
Base Ring

Let [Formula: see text] be an associative ring with nonzero identity. The zero-divisor graph [Formula: see text] of [Formula: see text] is the (undirected) graph with vertices the nonzero zero-divisors of [Formula: see text], and distinct vertices [Formula: see text] and [Formula: see text] are adjacent if and only if [Formula: see text] or [Formula: see text]. Let [Formula: see text] and [Formula: see text] be the set of all right annihilators and the set of all left annihilator of an element [Formula: see text], respectively, and let [Formula: see text]. The relation on [Formula: see text] given by [Formula: see text] if and only if [Formula: see text] is an equivalence relation. The compressed zero-divisor graph [Formula: see text] of [Formula: see text] is the (undirected) graph with vertices the equivalence classes induced by [Formula: see text] other than [Formula: see text] and [Formula: see text], and distinct vertices [Formula: see text] and [Formula: see text] are adjacent if and only if [Formula: see text] or [Formula: see text]. The goal of our paper is to study the diameter of zero-divisor and the compressed zero-divisor graph of skew Laurent polynomial rings over noncommutative rings. We give a complete characterization of the possible diameters of [Formula: see text] and [Formula: see text], where the base ring [Formula: see text] is reversible and also has the [Formula: see text]-compatible property.

scholarly journals On the diameter of compressed zero-divisor graphs of ore extensions

Filomat ◽  
2020 ◽  
Vol 34 (7) ◽  
pp. 2387-2400
Author(s):  
Ebrahim Hashemi ◽  
Mona Abdi
Keyword(s):  
Noetherian Ring ◽  
Zero Divisor ◽  
Complete Characterization ◽  
Noncommutative Rings ◽  
Zero Divisor Graph ◽  
Ongoing Effort ◽  
Ore Extensions ◽  
Base Ring

This paper continues the ongoing effort to study the compressed zero-divisor graph over noncommutative rings. The purpose of our paper is to study the diameter of the compressed zero-divisor graph of Ore extensions and give a complete characterization of the possible diameters of ?E(R[x; ?,?]), where the base ring R is reversible and also have the (?,?)-compatible property. Also, we give a complete characterization of the diameter of ?E (R[[x;?]]), where R is a reversible, ?-compatible and right Noetherian ring. By some examples, we show that all of the assumptions ?reversiblity?, ?(?,?)-compatiblity? and ?Noetherian? in our main results are crucial.

On zero-divisor graphs of skew polynomial rings over non-commutative rings

2017 ◽  
Vol 16 (03) ◽  
pp. 1750056 ◽  
Author(s):  
E. Hashemi ◽  
R. Amirjan ◽  
A. Alhevaz
Keyword(s):  
Associative Ring ◽  
Zero Divisor ◽  
Polynomial Rings ◽  
Zero Divisor Graph ◽  
Zero Divisors ◽  
Skew Polynomial Rings ◽  
Derivation Formula ◽  
Base Ring ◽  
Skew Polynomial ◽  
Associative Rings

In this paper, we continue to study zero-divisor properties of skew polynomial rings [Formula: see text], where [Formula: see text] is an associative ring equipped with an endomorphism [Formula: see text] and an [Formula: see text]-derivation [Formula: see text]. For an associative ring [Formula: see text], the undirected zero-divisor graph of [Formula: see text] is the graph [Formula: see text] such that the vertices of [Formula: see text] are all the nonzero zero-divisors of [Formula: see text] and two distinct vertices [Formula: see text] and [Formula: see text] are connected by an edge if and only if [Formula: see text] or [Formula: see text]. As an application of reversible rings, we investigate the interplay between the ring-theoretical properties of a skew polynomial ring [Formula: see text] and the graph-theoretical properties of its zero-divisor graph [Formula: see text]. Our goal in this paper is to give a characterization of the possible diameters of [Formula: see text] in terms of the diameter of [Formula: see text], when the base ring [Formula: see text] is reversible and also have the [Formula: see text]-compatible property. We also completely describe the associative rings all of whose zero-divisor graphs of skew polynomials are complete.

The zero-divisor graph of a ring with involution

2018 ◽  
Vol 17 (03) ◽  
pp. 1850050 ◽  
Author(s):  
Avinash Patil ◽  
B. N. Waphare
Keyword(s):  
Complete Graph ◽  
Zero Divisor ◽  
Undirected Graph ◽  
Sufficient Conditions ◽  
Left Zero ◽  
Star Graph ◽  
Artinian Rings ◽  
Zero Divisor Graph ◽  
Zero Divisors

For a *-ring [Formula: see text], we associate a simple undirected graph [Formula: see text] having all nonzero left zero-divisors of [Formula: see text] as vertices and, two vertices [Formula: see text] and [Formula: see text] are adjacent if [Formula: see text]. In case of Artinian *-rings and Rickart *-rings, characterizations are obtained for those *-rings having [Formula: see text] a complete graph or a star graph, and sufficient conditions are obtained for [Formula: see text] to be connected and also for [Formula: see text] to be disconnected. For a Rickart *-ring [Formula: see text], we characterize the girth of [Formula: see text] and prove a sort of Beck’s conjecture.

scholarly journals On Certain Bounds for Edge Metric Dimension of Zero-Divisor Graphs Associated with Rings

2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Hafiz Muahmmad Afzal Siddiqui ◽  
Ammar Mujahid ◽  
Muhammad Ahsan Binyamin ◽  
Muhammad Faisal Nadeem
Keyword(s):  
Zero Divisor ◽  
Research Work ◽  
Commutative Rings ◽  
Polynomial Rings ◽  
Metric Dimension ◽  
Gaussian Integers ◽  
Zero Divisor Graph ◽  
Zero Divisors ◽  
Algebraic Properties ◽  
Do So

Given a finite commutative unital ring S having some non-zero elements x ,   y such that x . y = 0 , the elements of S that possess such property are called the zero divisors, denoted by Z S . We can associate a graph to S with the help of zero-divisor set Z S , denoted by ζ S (called the zero-divisor graph), to study the algebraic properties of the ring S . In this research work, we aim to produce some general bounds for the edge version of metric dimension regarding zero-divisor graphs of S . To do so, we will discuss the zero-divisor graphs for the ring of integers ℤ m modulo m , some quotient polynomial rings, and the ring of Gaussian integers ℤ m i modulo m . Then, we prove the general result for the bounds of edge metric dimension of zero-divisor graphs in terms of maximum degree and diameter of ζ S . In the end, we provide the commutative rings with the same metric dimension, edge metric dimension, and upper dimension.

On defensive alliance in zero-divisor graphs

2020 ◽  
pp. 2150155
Author(s):  
Najat Muthana ◽  
Abdellah Mamouni
Keyword(s):  
Commutative Ring ◽  
Zero Divisor ◽  
Undirected Graph ◽  
Dominating Set ◽  
Complete Characterization ◽  
Minimum Cardinality ◽  
Number Formula ◽  
Finite Commutative Ring ◽  
Multiple Edges

Let [Formula: see text] be a finite undirected graph without loops or multiple edges. A non-empty set of vertices [Formula: see text] is called defensive alliance if every vertex in [Formula: see text] have at least one more neighbors inside of [Formula: see text] than it has outside of [Formula: see text]. A non-empty set of vertices [Formula: see text] is called a dominating set if every vertex not in [Formula: see text] is adjacent to at least one member of [Formula: see text]. A defensive alliance dominating set is called global. The global defensive alliance number [Formula: see text] is defined as the minimum cardinality among all global defensive alliances. In this paper, we initiate the study of the global defensive alliance number of zero-divisor graphs [Formula: see text] with [Formula: see text] is a finite commutative ring. Hence, we calculate [Formula: see text] for some usual kind of rings. We finish by a complete characterization of rings with [Formula: see text].

Locating sets and numbers of graphs associated to commutative rings

2014 ◽  
Vol 13 (07) ◽  
pp. 1450047 ◽  
Author(s):  
S. Pirzada ◽  
Rameez Raja ◽  
Shane Redmond
Keyword(s):  
Commutative Ring ◽  
Zero Divisor ◽  
Undirected Graph ◽  
Commutative Rings ◽  
Zero Divisor Graph ◽  
Zero Divisors ◽  
Finite Vector ◽  
Minimum Number

For a graph G(V, E) with order n ≥ 2, the locating code of a vertex v is a finite vector representing distances of v with respect to vertices of some ordered subset W of V(G). The set W is a locating set of G(V, E) if distinct vertices have distinct codes. A locating set containing a minimum number of vertices is a minimum locating set for G(V, E). The locating number denoted by loc (G) is the number of vertices in the minimum locating set. Let R be a commutative ring with identity 1 ≠ 0, the zero-divisor graph denoted by Γ(R), is the (undirected) graph whose vertices are the nonzero zero-divisors of R with two distinct vertices joined by an edge when the product of vertices is zero. We introduce and investigate locating numbers in zero-divisor graphs of a commutative ring R. We then extend our definition to study and characterize the locating numbers of an ideal based zero-divisor graph of a commutative ring R.

scholarly journals Zero-Divisor Graphs with respect to Ideals in Noncommutative Rings

2011 ◽  
Vol 2011 ◽  
pp. 1-7
Author(s):  
Shahabaddin Ebrahimi Atani ◽  
Ahmad Yousefian Darani
Keyword(s):  
Commutative Ring ◽  
Zero Divisor ◽  
Undirected Graph ◽  
Noncommutative Rings ◽  
Zero Divisor Graph ◽  
Vertex Set ◽  
Definition Of ◽  
The Ideal

Let R be a commutative ring and I an ideal of R. The zero-divisor graph of R with respect to I, denoted ΓI(R), is the undirected graph whose vertex set is {x∈R∖I|xy∈I for some y∈R∖I} with two distinct vertices x and y joined by an edge when xy∈I. In this paper, we extend the definition of the ideal-based zero-divisor graph to noncommutative rings.

scholarly journals On the star forest polytope for trees and cycles

2019 ◽  
Vol 53 (5) ◽  
pp. 1763-1773
Author(s):  
Meziane Aider ◽  
Lamia Aoudia ◽  
Mourad Baïou ◽  
A. Ridha Mahjoub ◽  
Viet Hung Nguyen
Keyword(s):  
Undirected Graph ◽  
Dominating Set ◽  
Discrete Math ◽  
Complete Characterization ◽  
Facial Structure ◽  
Maximum Weight ◽  
Single Node ◽  
End Node ◽  
Vertex Disjoint

Let G = (V, E) be an undirected graph where the edges in E have non-negative weights. A star in G is either a single node of G or a subgraph of G where all the edges share one common end-node. A star forest is a collection of vertex-disjoint stars in G. The weight of a star forest is the sum of the weights of its edges. This paper deals with the problem of finding a Maximum Weight Spanning Star Forest (MWSFP) in G. This problem is NP-hard but can be solved in polynomial time when G is a cactus [Nguyen, Discrete Math. Algorithms App. 7 (2015) 1550018]. In this paper, we present a polyhedral investigation of the MWSFP. More precisely, we study the facial structure of the star forest polytope, denoted by SFP(G), which is the convex hull of the incidence vectors of the star forests of G. First, we prove several basic properties of SFP(G) and propose an integer programming formulation for MWSFP. Then, we give a class of facet-defining inequalities, called M-tree inequalities, for SFP(G). We show that for the case when G is a tree, the M-tree and the nonnegativity inequalities give a complete characterization of SFP(G). Finally, based on the description of the dominating set polytope on cycles given by Bouchakour et al. [Eur. J. Combin. 29 (2008) 652–661], we give a complete linear description of SFP(G) when G is a cycle.

A generalized ideal-based zero-divisor graph

2015 ◽  
Vol 14 (06) ◽  
pp. 1550079 ◽  
Author(s):  
M. J. Nikmehr ◽  
S. Khojasteh
Keyword(s):  
Prime Ideal ◽  
Commutative Ring ◽  
Chromatic Number ◽  
Zero Divisor ◽  
Undirected Graph ◽  
Clique Number ◽  
Proper Ideal ◽  
Graph Structure ◽  
Zero Divisor Graph ◽  
Vertex Set

Let R be a commutative ring with identity, I its proper ideal and M be a unitary R-module. In this paper, we introduce and study a kind of graph structure of an R-module M with respect to proper ideal I, denoted by ΓI(RM) or simply ΓI(M). It is the (undirected) graph with the vertex set M\{0} and two distinct vertices x and y are adjacent if and only if [x : M][y : M] ⊆ I. Clearly, the zero-divisor graph of R is a subgraph of Γ0(R); this is an important result on the definition. We prove that if ann R(M) ⊆ I and H is the subgraph of ΓI(M) induced by the set of all non-isolated vertices, then diam (H) ≤ 3 and gr (ΓI(M)) ∈ {3, 4, ∞}. Also, we prove that if Spec (R) and ω(Γ Nil (R)(M)) are finite, then χ(Γ Nil (R)(M)) ≤ ∣ Spec (R)∣ + ω(Γ Nil (R)(M)). Moreover, for a secondary R-module M and prime ideal P, we determine the chromatic number and the clique number of ΓP(M), where ann R(M) ⊆ P. Among other results, it is proved that for a semisimple R-module M with ann R(M) ⊆ I, ΓI(M) is a forest if and only if ΓI(M) is a union of isolated vertices or a star.

Associate class graph of zero-divisors of a commutative ring

2019 ◽  
Vol 19 (08) ◽  
pp. 2050155
Author(s):  
Gaohua Tang ◽  
Guangke Lin ◽  
Yansheng Wu
Keyword(s):  
Commutative Ring ◽  
Chromatic Number ◽  
Zero Divisor ◽  
New Class ◽  
Associate Class ◽  
Zero Divisor Graph ◽  
Zero Divisors ◽  
Class Graph

In this paper, we introduce the concept of the associate class graph of zero-divisors of a commutative ring [Formula: see text], denoted by [Formula: see text]. Some properties of [Formula: see text], including the diameter, the connectivity and the girth are investigated. Utilizing this graph, we present a new class of counterexamples of Beck’s conjecture on the chromatic number of the zero-divisor graph of a commutative ring.

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