Results 21 to 30 of about 842,964 (161)

Clique-Relaxed Graph Coloring [PDF]

open access: yes, 2011
We define a generalization of the chromatic number of a graph G called the k-clique-relaxed chromatic number, denoted χ(k)(G). We prove bounds on χ(k)(G) for all graphs G, including corollaries for outerplanar and planar graphs.
Dunn, Charles   +5 more
core   +2 more sources

Alpha Labeling of Amalgamated Cycles

open access: yesTheory and Applications of Graphs, 2022
A graceful labeling of a bipartite graph is an \a-labeling if it has the property that the labels assigned to the vertices of one stable set of the graph are smaller than the labels assigned to the vertices of the other stable set.
Christian Barrientos
doaj   +1 more source

Star edge coloring of $ K_{2, t} $-free planar graphs

open access: yesAIMS Mathematics, 2023
The star chromatic index of a graph $ G $, denoted by $ \chi{'}_{st}(G) $, is the smallest number of colors required to properly color $ E(G) $ such that every connected bicolored subgraph is a path with no more than three edges.
Yunfeng Tang , Huixin Yin , Miaomiao Han
doaj   +1 more source

Every Property of Outerplanar Graphs is Testable [PDF]

open access: yes, 2016
A D-disc around a vertex v of a graph G=(V,E) is the subgraph induced by all vertices of distance at most D from v. We show that the structure of an outerplanar graph on n vertices is determined, up to modification (insertion or deletion) of at most ...
Babu, Jasine   +2 more
core   +1 more source

On the Planarity of Generalized Line Graphs

open access: yesTheory and Applications of Graphs, 2019
One of the most familiar derived graphs is the line graph. The line graph $L(G)$ of a graph $G$ is that graph whose vertices are the edges of $G$ where two vertices of $L(G)$ are adjacent if the corresponding edges are adjacent in~$G$.
Khawlah H. Alhulwah   +2 more
doaj   +1 more source

On Supergraphs Satisfying CMSO Properties [PDF]

open access: yesLogical Methods in Computer Science, 2021
Let CMSO denote the counting monadic second order logic of graphs. We give a constructive proof that for some computable function $f$, there is an algorithm $\mathfrak{A}$ that takes as input a CMSO sentence $\varphi$, a positive integer $t$, and a ...
Mateus de Oliveira Oliveira
doaj   +1 more source

On Another Class of Strongly Perfect Graphs

open access: yesMathematics, 2022
For a commutative ring R with unity, the associate ring graph, denoted by AG(R), is a simple graph with vertices as nonzero elements of R and two distinct vertices are adjacent if they are associates.
Neha Kansal   +3 more
doaj   +1 more source

The Degree-Diameter Problem for Outerplanar Graphs

open access: yesDiscussiones Mathematicae Graph Theory, 2017
For positive integers Δ and D we define nΔ,D to be the largest number of vertices in an outerplanar graph of given maximum degree Δ and diameter D. We prove that nΔ,D=ΔD2+O (ΔD2−1)$n_{\Delta ,D} = \Delta ^{{D \over 2}} + O\left( {\Delta ^{{D \over 2 ...
Dankelmann Peter   +2 more
doaj   +1 more source

Space-Efficient Biconnected Components and Recognition of Outerplanar Graphs [PDF]

open access: yes, 2016
We present space-efficient algorithms for computing cut vertices in a given graph with $n$ vertices and $m$ edges in linear time using $O(n+\min\{m,n\log \log n\})$ bits.
Kammer, Frank   +2 more
core   +2 more sources

Characterization of outerplanar graphs with equal 2-domination and domination numbers

open access: yesTheory and Applications of Graphs, 2022
A {\em $k$-domination number} of a graph $G$ is minimum cardinality of a $k$-dominating set of $G$, where a subset $S \subseteq V(G)$ is a {\em $k$-dominating set} if each vertex $v\in V(G)\setminus S$ is adjacent to at least $k$ vertices in $S$.
Naoki Matsumoto
doaj   +1 more source

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