Results 31 to 40 of about 390,323 (304)

Coloring Some Finite Sets in ℝn

open access: yesDiscussiones Mathematicae Graph Theory, 2013
This note relates to bounds on the chromatic number χ(ℝn) of the Euclidean space, which is the minimum number of colors needed to color all the points in ℝn so that any two points at the distance 1 receive different colors. In [6] a sequence of graphs Gn
Balogh József   +2 more
doaj   +1 more source

Connected Domination Number and a New Invariant in Graphs with Independence Number Three [PDF]

open access: yesComputer Science Journal of Moldova, 2021
Adding a connected dominating set of vertices to a graph $G$ increases its number of Hadwiger $h(G)$. Based on this obvious property in [2] we introduced a new invariant $\eta(G)$ for which $\eta(G)\leq h(G)$. We continue to study its property.
Vladimir Bercov
doaj  

Relations between the distinguishing number and some other graph parameters [PDF]

open access: yesریاضی و جامعه
A distinguishing coloring of a simple graph $G$ is a vertex coloring of $G$ which is preserved only by the identity automorphism of $G$. In other words, this coloring ``breaks'' all symmetries of $G$.
Bahman Ahmadi   +1 more
doaj   +1 more source

Min-Max Dom-Saturation Number of a Tree [PDF]

open access: yes, 2010
In this paper we present a dynamic programming algorithm for determining the min-max domsaturation number of a ...
Sudha, S., Arumugam, S.
core   +1 more source

ON PROPERTIES OF PRIME IDEAL GRAPHS OF COMMUTATIVE RINGS

open access: yesBarekeng, 2023
The prime ideal graph of  in a finite commutative ring  with unity, denoted by , is a graph with elements of  as its vertices and two elements in  are adjacent if their product is in . In this paper, we explore some interesting properties of .
Rian Kurnia   +5 more
doaj   +1 more source

On the Number of Independent Sets in a Tree [PDF]

open access: yesThe Electronic Journal of Combinatorics, 2010
We show in a simple way that for any $k,m\in{\Bbb N}$, there exists a tree $T$ such that the number of independent sets of $T$ is congruent to $k$ modulo $m$. This resolves a conjecture of Wagner (Almost all trees have an even number of independent sets, Electron. J. Combin. 16 (2009), # R93).
openaire   +2 more sources

On θ-commutators and the corresponding non-commuting graphs

open access: yesOpen Mathematics, 2017
The θ-commutators of elements of a group with respect to an automorphism are introduced and their properties are investigated. Also, corresponding to θ-commutators, we define the θ-non-commuting graphs of groups and study their correlations with other ...
Shalchi S., Erfanian A., Farrokhi DG M.
doaj   +1 more source

ON THE GIRTH, INDEPENDENCE NUMBER, AND WIENER INDEX OF COPRIME GRAPH OF DIHEDRAL GROUP

open access: yesBarekeng, 2023
The coprime graph of a finite group , denoted by , is a graph with vertex set  such that two distinct vertices  and  are adjacent if and only if their orders are coprime, i.e.,  where |x| is the order of x.
Agista Surya Bawana   +2 more
doaj   +1 more source

The independent resolving number of a graph [PDF]

open access: yesMathematica Bohemica, 2003
Summary: For an ordered set \(W = \{w_1, w_2, \dots , w_k\}\) of vertices in a connected graph \(G\) and a vertex \(v\) of \(G\), the code of \(v\) with respect to \(W\) is the \(k\)-vector \[ c_W (v) = (d (v, w_1), d (v, w_2), \dots , d (v, w_k)). \] The set \(W\) is an independent resolving set for \(G\) if (1) \(W\) is independent in \(G\) and (2 ...
Chartrand, G.   +2 more
openaire   +2 more sources

Note on the smallest root of the independence polynomial

open access: yes, 2013
One can define the independence polynomial of a graph G as follows. Let i(k)(G) denote the number of independent sets of size k of G, where i(0)(G) = 1. Then the independence polynomial of G is I(G,x) = Sigma(n)(k=0)(-1)(k)i(k)(G)x(k).
Csíkvári, Péter
core   +1 more source

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