Domination in total graphs of small rings

2016 ◽  
Vol 08 (04) ◽  
pp. 1650069
Author(s):  
Alpesh M. Dhorajia ◽  
Jimmy M. Morzaria

Let [Formula: see text] be a commutative ring and [Formula: see text] be its set of zero divisors. The total graph of [Formula: see text] (introduced by Anderson and Badawi) denoted by [Formula: see text]. For any positive integers [Formula: see text] and [Formula: see text] we obtain the domination number of the total graph of [Formula: see text]. We also obtain various domination parameters including [Formula: see text] and [Formula: see text]. Finally we explore domination parameters in the complement of the total graph [Formula: see text].

2013 ◽  
Vol 12 (04) ◽  
pp. 1250198 ◽  
Author(s):  
T. TAMIZH CHELVAM ◽  
T. ASIR

Let R be a commutative ring and Z(R) be its set of all zero-divisors. Anderson and Badawi [The total graph of a commutative ring, J. Algebra320 (2008) 2706–2719] introduced the total graph of R, denoted by TΓ(R), as the undirected graph with vertex set R, and two distinct vertices x and y are adjacent if and only if x + y ∈ Z(R). Tamizh Chelvam and Asir [Domination in the total graph of a commutative ring, to appear in J. Combin. Math. Combin. Comput.] obtained the domination number of the total graph and studied certain other domination parameters of TΓ(R) where R is a commutative Artin ring. The intersection graph of gamma sets in TΓ(R) is denoted by ITΓ(R). Tamizh Chelvam and Asir [Intersection graph of gamma sets in the total graph, Discuss. Math. Graph Theory32 (2012) 339–354, doi:10.7151/dmgt.1611] initiated a study about the intersection graph ITΓ (ℤn) of gamma sets in TΓ(ℤn). In this paper, we study about ITΓ(R), where R is a commutative Artin ring. Actually we investigate the interplay between graph-theoretic properties of ITΓ(R) and ring-theoretic properties of R. At the first instance, we prove that diam (ITΓ(R)) ≤ 2 and gr (ITΓ(R)) ≤ 4. Also some characterization results regarding completeness, bipartite, cycle and chordal nature of ITΓ(R) are given. Further, we discuss about the vertex-transitive property of ITΓ(R). At last, we obtain all commutative Artin rings R for which ITΓ(R) is either planar or toroidal or genus two.


2015 ◽  
Vol 07 (01) ◽  
pp. 1550004 ◽  
Author(s):  
Alpesh M. Dhorajia

Let R be a commutative ring and Z(R) be the set of all zero-divisors of R. The total graph of R, denoted by T Γ(R), is the (undirected) graph with vertices set R. For any two distinct elements x, y ∈ R, the vertices x and y are adjacent if and only if x + y ∈ Z(R). In this paper, we obtain certain fundamental properties of the total graph of ℤn × ℤm, where n and m are positive integers. We determine the clique number and independent number of the total graph T Γ(ℤn × ℤm).


2011 ◽  
Vol 03 (04) ◽  
pp. 413-421 ◽  
Author(s):  
T. TAMIZH CHELVAM ◽  
T. ASIR

For a commutative ring R, let Z(R) be its set of zero-divisors. The total graph of R, denoted by TΓ(R), is the undirected graph with vertex set R, and for distinct x, y ∈ R, the vertices x and y are adjacent if and only if x + y ∈ Z(R). Tamizh Chelvam and Asir studied about the domination in the total graph of a commutative ring R. In particular, it was proved that the domination number γ(TΓ(ℤn)) = p1 where p1 is the smallest prime divisor of n. In this paper, we characterize all the γ-sets in TΓ(ℤn). Also, we obtain the values of other domination parameters like independent, total and perfect domination numbers of the total graph on ℤn.


2012 ◽  
Vol 11 (04) ◽  
pp. 1250074 ◽  
Author(s):  
DAVID F. ANDERSON ◽  
AYMAN BADAWI

Let R be a commutative ring with nonzero identity, and let Z(R) be its set of zero-divisors. The total graph of R is the (undirected) graph T(Γ(R)) with vertices all elements of R, and two distinct vertices x and y are adjacent if and only if x + y ∈ Z(R). In this paper, we study the two (induced) subgraphs Z0(Γ(R)) and T0(Γ(R)) of T(Γ(R)), with vertices Z(R)\{0} and R\{0}, respectively. We determine when Z0(Γ(R)) and T0(Γ(R)) are connected and compute their diameter and girth. We also investigate zero-divisor paths and regular paths in T0(Γ(R)).


2020 ◽  
Vol 27 (03) ◽  
pp. 469-476 ◽  
Author(s):  
A. Cherrabi ◽  
H. Essannouni ◽  
E. Jabbouri ◽  
A. Ouadfel

In this paper, we introduce a new graph whose vertices are the non-zero zero-divisors of a commutative ring R, and for distincts elements x and y in the set Z(R)* of the non-zero zero-divisors of R, x and y are adjacent if and only if xy = 0 or x + y ∈ Z(R). We present some properties and examples of this graph, and we study its relationship with the zero-divisor graph and with a subgraph of the total graph of a commutative ring.


Mathematics ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 482
Author(s):  
Bilal A. Rather ◽  
Shariefuddin Pirzada ◽  
Tariq A. Naikoo ◽  
Yilun Shang

Given a commutative ring R with identity 1≠0, let the set Z(R) denote the set of zero-divisors and let Z*(R)=Z(R)∖{0} be the set of non-zero zero-divisors of R. The zero-divisor graph of R, denoted by Γ(R), is a simple graph whose vertex set is Z*(R) and each pair of vertices in Z*(R) are adjacent when their product is 0. In this article, we find the structure and Laplacian spectrum of the zero-divisor graphs Γ(Zn) for n=pN1qN2, where p<q are primes and N1,N2 are positive integers.


2013 ◽  
Vol 05 (04) ◽  
pp. 1350035
Author(s):  
MOJGAN AFKHAMI ◽  
KAZEM KHASHYARMANESH

Let R be a commutative ring. The total graph of R, denoted by T(Γ(R)), is a graph with all elements of R as vertices, and two distinct vertices x, y ∈ R are adjacent if and only if x + y ∈ Z(R), where Z(R) denotes the set of zero-divisors of R. In this paper, we examine the preservation of the diameter, girth and completeness of T(Γ(R)) under extension to polynomial rings and rings of fractions. We also study the chromatic index, clique number and independence number of T(Γ(R)).


2019 ◽  
Vol 18 (10) ◽  
pp. 1950190 ◽  
Author(s):  
Alen Ðurić ◽  
Sara Jevđenić ◽  
Polona Oblak ◽  
Nik Stopar

In this paper, we initiate the study of the total zero-divisor graph over a commutative ring with unity. This graph is constructed by both relations that arise from the zero-divisor graph and from the total graph of a ring and give a joint insight of the structure of zero-divisors in a ring. We characterize Artinian rings with the connected total zero-divisor graphs and give their diameters. Moreover, we compute major characteristics of the total zero-divisor graph of the ring [Formula: see text] of integers modulo [Formula: see text] and prove that the total zero-divisor graphs of [Formula: see text] and [Formula: see text] are isomorphic if and only if [Formula: see text].


2020 ◽  
Vol 107 (121) ◽  
pp. 85-92
Author(s):  
Mitra Jalali ◽  
Reza Nikandish ◽  
Abolfazl Tehranian

Let R be a commutative ring with identity, and let Z(R) be the set of zero-divisors of R. The total graph of R is the graph T(?(R)) whose vertices are all elements of R, and two distinct vertices x and y are adjacent if and only if x + y ? Z(R). We investigate the perfectness of the graphs Z0(?(R)), T0(?(R)) and T(?(R)), where Z0(?(R)) and T0(?(R)) are (induced) subgraphs of T(?(R)) on Z(R)* = Z(R) \ {0} and R* = R \ {0}, respectively.


2015 ◽  
Vol 15 (01) ◽  
pp. 1650014 ◽  
Author(s):  
Rameez Raja ◽  
S. Pirzada ◽  
Shane Redmond

Let R be a commutative ring with identity and let G(V, E) be a graph. The locating number of the graph G(V, E) denoted by loc (G) is the cardinality of the minimal locating set W ⊆ V(G). To get the loc (G), we assign locating codes to the vertices V(G)∖W of G in such a way that every two vertices get different codes. In this paper, we consider the ratio of loc (G) to |V(G)| and show that there is a finite connected graph G with loc (G)/|V(G)| = m/n, where m < n are positive integers. We examine two equivalence relations on the vertices of Γ(R) and the relationship between locating sets and the cut vertices of Γ(R). Further, we obtain bounds for the locating number in zero-divisor graphs of a commutative ring and discuss the relation between locating number, domination number, clique number and chromatic number of Γ(R). We also investigate the locating number in Γ(R) when R is a finite product of rings.


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