Results 51 to 60 of about 2,073 (195)
The Planar Index and Outerplanar Index of Some Graphs Associated to Commutative Rings
Discussiones Mathematicae - General Algebra and Applications, 2019 In this paper, we study the planar and outerplanar indices of some graphs associated to a commutative ring. We give a full characterization of these graphs with respect to their planar and outerplanar indices when R is a finite ring.
Barati Zahra, Afkhami Mojgan
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Directed Acyclic Outerplanar Graphs Have Constant Stack Number [PDF]
TheoretiCSThe stack number of a directed acyclic graph $G$ is the minimum $k$ for which there is a topological ordering of $G$ and a $k$-coloring of the edges such that no two edges of the same color cross, i.e., have alternating endpoints along the topological ...
Paul Jungeblut +2 more
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On Large Induced Outerplanar Subgraphs in 2-Outerplanar Graphs
Graphs and CombinatoricsAbstract Borradaile, Le and Sherman-Bennett [ Graphs and Combinatorics , 2017] proved that every n -vertex 2-outerplane graph has a set of at least 2 n /3 vertices that induces an outerplane ...
Marco D'Elia, Fabrizio Frati
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Drawing Outer 1-planar Graphs with Few Slopes
Journal of Graph Algorithms and Applications, 2015 A graph is outer 1-planar if it admits a drawing where each vertex is on the outer face and each edge is crossed by at most another edge. Outer 1-planar graphs are a superclass of the outerplanar graphs and a subclass of the planar partial 3-trees.
Emilio Di Giacomo +2 more
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Double domination in maximal outerplanar graphs
Open Mathematics, 2022 In graph GG, a vertex dominates itself and its neighbors. A subset S⊆V(G)S\subseteq V\left(G) is said to be a double-dominating set of GG if SS dominates every vertex of GG at least twice.
Zhuang Wei, Zheng Qiuju
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On k-edge-magic labelings of maximal outerplanar graphs
AKCE International Journal of Graphs and Combinatorics, 2015 Let G be a graph with vertex set V and edge set E such that |V|=p and |E|=q. We denote this graph by (p,q)-graph. For integers k≥0, define a one-to-one map f from E to {k,k+1,…,k+q−1} and define the vertex sum for a vertex v as the sum of the labels of ...
Gee-Choon Lau +3 more
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The Minimal Nonplanar Strong Digraphs
Journal of Graph Theory, EarlyView.ABSTRACT Kuratowski's theorem says that the minimal (under subgraph containment) graphs that are not planar are the subdivisions of K 5 ${K}_{5}$ and of K 3 , 3 ${K}_{3,3}$. Here we study the minimal (under subdigraph containment) strongly‐connected digraphs that are not planar.
Stephen Bartell, Paul Seymour
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On the Threshold for Triangulations Inside Convex Polygons
Random Structures &Algorithms, Volume 69, Issue 2, September 2026.ABSTRACT Start with a large convex polygon and add all other edges inside independently with probability p$$ p $$. At what critical threshold pc$$ {p}_c $$ do triangulations of the polygon begin to appear? The first author and Gravner asked this question and observed that pc=Θ(1)$$ {p}_c=\Theta (1) $$, using the relationship with the Catalan numbers ...
Brett Kolesnik +2 more
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Algorithms, 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
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Toric ideals of matching polytopes and edge colorings
Mathematika, Volume 72, Issue 2, April 2026.Abstract In this paper, we investigate the maximal degree of minimal generators of the toric ideal of the matching polytope of a graph. It is known that the toric ideal associated with a bipartite graph is generated by binomials of degree at most 3.
Kenta Mori +3 more
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