Results 61 to 70 of about 1,010 (104)
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 non-commuting graph of a non-central hypergroup
Open Mathematics, 2019 The aim of this paper is to construct and study the properties of a certain graph associated with a non-central hypergroup, i.e. a hypergroup having non-commutative the associated fundamental group.
Iranmanesh Mahdiyeh +2 more
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On the Cayley digraphs that are patterns of unitary matrices
, 2002 A digraph D is the pattern of a matrix M when D has an arc ij if and only if the ij-th entry of M is nonzero. Study the relationship between unitary matrices and their patterns is motivated by works in quantum chaology and quantum computation.
Severini, Simone
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Chromatic number of Euclidean plane
, 2015 If the chromatic number of Euclidean plane is larger than four, but it is known that the chromatic number of planar graphs is equal to four, then how does one explain it? In my opinion, they are contradictory to each other. This idea leads to confirm the
Wang, Kai-Rui
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Sharp Upper Bounds on the Clar Number of Fullerene Graphs
Discussiones Mathematicae Graph Theory, 2018 The Clar number of a fullerene graph with n vertices is bounded above by ⌊n/6⌋ − 2 and this bound has been improved to ⌊n/6⌋ − 3 when n is congruent to 2 modulo 6.
Gao Yang, Zhang Heping
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Some stable and closed-shell structures of anticancer drugs by graph theoretical parameters. [PDF]
Heliyon, 2023 Koam ANA +4 more
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The absence of efficient dual pairs of spanning trees in planar graphs
, 2005 A spanning tree T in a finite planar connected graph G determines a dual spanning tree T* in the dual graph G such that T and T* do not intersect. We show that it is not always possible to find T in G, such that the diameters of T and T* are both within ...
Riley, T. R., Thurston, W. P.
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On the Hamiltonian Number of a Plane Graph
Discussiones Mathematicae Graph Theory, 2019 The Hamiltonian number of a connected graph is the minimum of the lengths of the closed spanning walks in the graph. In 1968, Grinberg published a necessary condition for the existence of a Hamiltonian cycle in a plane graph, formulated in terms of the ...
Lewis Thomas M.
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Facial Rainbow Coloring of Plane Graphs
Discussiones Mathematicae Graph Theory, 2019 A vertex coloring of a plane graph G is a facial rainbow coloring if any two vertices of G connected by a facial path have distinct colors. The facial rainbow number of a plane graph G, denoted by rb(G), is the minimum number of colors that are necessary
Jendroľ Stanislav, Kekeňáková Lucia
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On polyhedral graphs and their complements. [PDF]
Aequ Math, 2022 Maffucci RW.
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