Results 21 to 30 of about 122 (118)

On Laplacian spectrum of unitary Cayley graphs [PDF]

open access: yesActa Universitatis Sapientiae, Informatica, 2021
Abstract Let R be a commutative ring with unity 1 ≠ 0 and let R× be the set of all unit elements of R. The unitary Cayley graph of R, denoted by GR = Cay(R, R×), is a simple graph whose vertex set is R and there is an edge between two distinct vertices x and y of R if and only if x − y ∈ R×.
Pirzada S., Barati Z., Afkhami M.
openaire   +2 more sources

Domination in Cayley graphs: A survey

open access: yesAKCE International Journal of Graphs and Combinatorics, 2019
Let Ω be a symmetric generating set of a finite group Γ. Assume that (Γ,Ω)be such that Γ=〈Ω〉and Ω satisfies the two conditions C1: the identity element e∉Ω and C2: if a∈Ω, then a−1∈Ω. Given (Γ,Ω)satisfying C1and C2, define a Cayley graph G=Cay(Γ,Ω)with V(
T. Tamizh Chelvam, M. Sivagami
doaj   +1 more source

Polynomials of unitary Cayley graphs

open access: yesFilomat, 2015
The unitary Cayley graph Xn has the vertex set Zn = {0,1,2,..., n-1} and vertices a and b are adjacent, if and only if gcd(a-b,n) = 1. In this paper, we present some properties of the clique, independence and distance polynomials of the unitary Cayley graphs and generalize some of the results from [W. Klotz, T.
Milan Basic, Aleksandar Ilic
openaire   +2 more sources

Unitary Cayley Meet Signed Graphs

open access: yesElectronic Notes in Discrete Mathematics, 2017
Abstract A signed graph S is a graph in which every edge receive either ‘+’ or ‘-’ called the signs of the edges. The unitary Cayley graph Xn is a graph with vertex set Zn, the integers modulo n, where n is a positive integer greater than 1. Two vertices x1 and x2 are adjacent in the unitary Cayley graph if and only if their difference is in Un ...
Deepa Sinha, Ayushi Dhama
openaire   +1 more source

On the Unitary Cayley Graph of a Ring [PDF]

open access: yesThe Electronic Journal of Combinatorics, 2012
Let $R$ be a ring with identity. The unitary Cayley graph of a ring $R$, denoted by $G_{R}$, is the graph, whose vertex set is $R$, and in which $\{x,y\}$ is an edge if and only if $x-y$ is a unit of $R$. In this paper we find chromatic, clique and independence number of $G_{R}$, where $R$ is a finite ring.
Kiani, Dariush   +1 more
openaire   +2 more sources

Generalized boundary triples, I. Some classes of isometric and unitary boundary pairs and realization problems for subclasses of Nevanlinna functions

open access: yesMathematische Nachrichten, Volume 293, Issue 7, Page 1278-1327, July 2020., 2020
Abstract With a closed symmetric operator A in a Hilbert space H a triple Π={H,Γ0,Γ1} of a Hilbert space H and two abstract trace operators Γ0 and Γ1 from A∗ to H is called a generalized boundary triple for A∗ if an abstract analogue of the second Green's formula holds.
Volodymyr Derkach   +2 more
wiley   +1 more source

A Classification of Ramanujan Unitary Cayley Graphs [PDF]

open access: yesThe Electronic Journal of Combinatorics, 2010
The unitary Cayley graph on $n$ vertices, $X_n$, has vertex set ${\Bbb Z}/{n\Bbb Z}$, and two vertices $a$ and $b$ are connected by an edge if and only if they differ by a multiplicative unit modulo $n$, i.e. ${\rm gcd}(a-b,n) = 1$. A $k$-regular graph $X$ is Ramanujan if and only if $\lambda(X) \leq 2\sqrt{k-1}$ where $\lambda(X)$ is the second ...
openaire   +2 more sources

Perfect state transfer in unitary Cayley graphs over local rings [PDF]

open access: yesTransactions on Combinatorics, 2014
In this work, using eigenvalues and eigenvectors of unitary Cayley graphs over finite local rings and elementary linear algebra, we characterize which local rings allowing PST occurring in its unitary Cayley graph.
Yotsanan Meemark , Songpon Sriwongsa
doaj  

On unitary Cayley graphs of matrix rings

open access: yesDiscrete Mathematics, 2022
A unitary Cayley graph \(C_R\) of a ring \(R\) is the graph whose vertex set consists of the elements of \(R\) and two vertices \(x\), \(y\) are adjacent if and only if \(x-y\) is a unit of \(R\). The authors of the paper investigate the spectra of the Cayley graphs of matrix rings \(M_n(F_q)\) and \(M_n(R)\), where \(R\) is a finite commutative ring ...
Chen, Bocong, Huang, Jing
openaire   +2 more sources

The energy of unitary cayley graphs

open access: yesLinear Algebra and its Applications, 2009
zbMATH Open Web Interface contents unavailable due to conflicting licenses.
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