Results 21 to 30 of about 1,999,234 (282)
Open Journal of Discrete Mathematics, 2015 The independence number of a graph G is the maximum cardinality among all independent sets of G. For any tree T of order n ≥ 2, it is easy to see that . In addition, if there are duplicated leaves in a tree, then these duplicated leaves are all lying in every maximum independent set.
Min-Jen Jou, Jenq-Jong Lin
openaire +2 more sources
On the signed $2$-independence number of graphs
Electronic Journal of Graph Theory and Applications, 2017 In this paper, we study the signed 2-independence number in graphs and give new sharp upper and lower bounds on the signed 2-independence number of a graph by a simple uniform approach.
S.M. Hosseini Moghaddam +3 more
doaj +1 more source
Coloring Some Finite Sets in ℝn
Discussiones 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]
Computer 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]
ریاضی و جامعهA 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
The critical window for the classical Ramsey-Tur\'an problem [PDF]
, 2012 The first application of Szemer\'edi's powerful regularity method was the following celebrated Ramsey-Tur\'an result proved by Szemer\'edi in 1972: any K_4-free graph on N vertices with independence number o(N) has at most (1/8 + o(1)) N^2 edges.
A. Frieze +42 more
core +2 more sources
Independence number in n-extendable graphs
Discrete Mathematics, 1996 zbMATH Open Web Interface contents unavailable due to conflicting licenses.
Maschlanka, Peter, Volkmann, Lutz
openaire +2 more sources
On Selkow’s Bound on the Independence Number of Graphs
Discussiones Mathematicae Graph Theory, 2019 For a graph G with vertex set V (G) and independence number α(G), Selkow [A Probabilistic lower bound on the independence number of graphs, Discrete Math. 132 (1994) 363–365] established the famous lower bound ∑v∈V(G)1d(v)+1(1+max{d(v)d(v)+1-∑u∈N(v)1d(u)+
Harant Jochen, Mohr Samuel
doaj +1 more source
ON PROPERTIES OF PRIME IDEAL GRAPHS OF COMMUTATIVE RINGS
Barekeng, 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
, 2012 What are the strategies, modalities and aspirations of island-based, stateless nationalist and regionalist parties in the twenty-first century? Political independence is now easier to achieve, even by the smallest of territories; yet, it is not so likely
Armstrong H. W. +16 more
core +1 more source