Results 81 to 90 of about 119,166 (199)
A note on zero-divisor graph of amalgamated duplication of a ring along an ideal
AKCE International Journal of Graphs and Combinatorics, 2017 Let be a commutative ring and be a non-zero ideal of . Let be the subring of consisting of the elements for and . In this paper we characterize all isomorphism classes of finite commutative rings with identity and ideal such that is planar.
A. Mallika, R. Kala
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Generalized Outerplanar Turán numbers and maximum number of k-vertex subtrees [PDF]
arXiv, 2021 We prove an asymptotic result on the maximum number of k-vertex subtrees in binary trees of given order. This problem turns out to be equivalent to determine the maximum number of k+2-cycles in n-vertex outerplanar graphs, thus we settle the generalized outerplanar Tur\'an number for all cycles.
arxiv
Minimum rank of outerplanar graphs
Linear Algebra and its Applications, 2012 AbstractThe problem of finding the minimum rank over all symmetric matrices corresponding to a given graph has grown in interest recently. It is well known that the minimum rank of any graph is bounded above by the clique cover number, the minimum number of cliques needed to cover all edges of the graph.
John Sinkovic, Mark Kempton
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On the Intersection Graphs Associeted to Posets
Discussiones Mathematicae - General Algebra and Applications, 2020 Let (P, ≤) be a poset with the least element 0. The intersection graph of ideals of P, denoted by G(P), is a graph whose vertices are all nontrivial ideals of P and two distinct vertices I and J are adjacent if and only if I ∩ J ≠ {0}.
Afkhami M. +2 more
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The Cayley Sum Graph of Ideals of a Lattice
Discussiones Mathematicae - General Algebra and Applications, 2020 Let L be a lattice, 𝒥(L) be the set of ideals of L and S be a subset of 𝒥 (L). In this paper, we introduce an undirected Cayley graph of L, denoted by ΓL,S with elements of 𝒥 (L) as the vertex set and, for two distinct vertices I and J, I is adjacent to ...
Afkhami Mojgan +2 more
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Drawing outerplanar graphs using three edge lengths
Computational Geometry, 2015 It is shown that for any outerplanar graph G there is a one to one mapping of the vertices of G to the plane, so that the number of distinct distances between pairs of connected vertices is at most three. This settles a problem of Carmi, Dujmovic, Morin and Wood.
Ohad N. Feldheim, Noga Alon
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Crosscap of the non-cyclic graph of groups
AKCE International Journal of Graphs and Combinatorics, 2016 The non-cyclic graph CG to a non locally cyclic group G is as follows: take G∖Cyc(G) as vertex set, where Cyc(G)={x∈G|〈x,y〉 is cyclic for all y∈G} is called the cyclicizer of G, and join two vertices if they do not generate a cyclic subgroup.
K. Selvakumar, M. Subajini
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Outerplanar Partitions of Planar Graphs
Journal of Combinatorial Theory, Series B, 1996 AbstractAnouterplanargraph is one that can be embedded in the plane so that all of the vertices lie on one of the faces. We investigate a conjecture of Chartrand, Geller, and Hedetniemi, that every planar graph can be edge-partitioned into two outerplanar subgraphs.
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A Branch and Bound Algorithm for Counting Independent Sets on Grid Graphs
Computer Sciences & Mathematics Forum, 2023 A relevant problem in combinatorial mathematics is the problem of counting independent sets of a graph G, denoted by i(G). This problem has many applications in combinatorics, physics, chemistry and computer science.
Guillermo De Ita +2 more
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A Survey of Maximal k-Degenerate Graphs and k-Trees
Theory and Applications of GraphsThis article surveys results on maximal $k$-degenerate graphs, $k$-trees, and related classes including simple $k$-trees, $k$-paths, maximal outerplanar graphs, and Apollonian networks.
Allan Bickle
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