Results 41 to 50 of about 119,166 (199)

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

Nonplanarity of Iterated Line Graphs

open access: yesJournal of Mathematics, Volume 2020, Issue 1, 2020., 2020
The 1‐crossing index of a graph G is the smallest integer k such that the kth iterated line graph of G has crossing number greater than 1. In this paper, we show that the 1‐crossing index of a graph is either infinite or it is at most 5. Moreover, we give a full characterization of all graphs with respect to their 1‐crossing index.
Jing Wang, Alfred Peris
wiley   +1 more source

Packing colorings of subcubic outerplanar graphs [PDF]

open access: yesAequationes mathematicae, 2020
Given a graph $G$ and a nondecreasing sequence $S=(s_1,\ldots,s_k)$ of positive integers, the mapping $c:V(G)\longrightarrow \{1,\ldots,k\}$ is called an $S$-packing coloring of $G$ if for any two distinct vertices $x$ and $y$ in $c^{-1}(i)$, the distance between $x$ and $y$ is greater than $s_i$. The smallest integer $k$ such that there exists a $(1,2,
Nicolas Gastineau   +3 more
openaire   +5 more sources

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

Game Chromatic Number of Generalized Petersen Graphs and Jahangir Graphs

open access: yesJournal of Applied Mathematics, Volume 2020, Issue 1, 2020., 2020
Let G = (V, E) be a graph, and two players Alice and Bob alternate turns coloring the vertices of the graph G a proper coloring where no two adjacent vertices are signed with the same color. Alice′s goal is to color the set of vertices using the minimum number of colors, which is called game chromatic number and is denoted by χg(G), while Bob′s goal is
Ramy Shaheen   +3 more
wiley   +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

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

A Polynomial-Time Algorithm for Computing the Maximum Common Connected Edge Subgraph of Outerplanar Graphs of Bounded Degree

open access: yesAlgorithms, 2013
The maximum common connected edge subgraph problem is to find a connected graph with the maximum number of edges that is isomorphic to a subgraph of each of the two input graphs, where it has applications in pattern recognition and chemistry.
Takeyuki Tamura, Tatsuya Akutsu
doaj   +1 more source

Scaling Limits of Random Graphs from Subcritical Classes: Extended abstract [PDF]

open access: yesDiscrete Mathematics & Theoretical Computer Science, 2015
We study the uniform random graph $\mathsf{C}_n$ with $n$ vertices drawn from a subcritical class of connected graphs. Our main result is that the rescaled graph $\mathsf{C}_n / \sqrt{n}$ converges to the Brownian Continuum Random Tree $\mathcal{T}_ ...
Konstantinos Panagiotou   +2 more
doaj   +1 more source

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