Results 1 to 10 of about 183 (88)
A Note on Edge-Group Choosability of Planar Graphs without 5-Cycles
Journal of Mathematics, 2020 This paper is devoted to a study of the concept of edge-group choosability of graphs. We say that G is edge-k-group choosable if its line graph is k-group choosable.
Amir Khamseh
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Recent developments in combinatorial aspects of normal ordering
Enumerative Combinatorics and Applications, 2021 In this paper, we report on recent progress concerning combinatorial aspects of normal ordering. After giving a short introduction to the history and motivation of normal ordering, we present some recent developments.
M. Schork
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Electronic Journal of Graph Theory and Applications, 2021 The d-Fibonacci digraphs F (d, k), introduced here, have the number of vertices following some generalized Fibonacci-like sequences. They can be defined both as digraphs on alphabets and as iterated line digraphs.
C. Dalfó, M. A. Fiol
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On L(2, 1)-Labelings of Oriented Graphs
Discussiones Mathematicae Graph Theory, 2022 We extend a result of Griggs and Yeh about the maximum possible value of the L(2, 1)-labeling number of a graph in terms of its maximum degree to oriented graphs.
Colucci Lucas, Győri Ervin
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Ascending Subgraph Decompositions of Oriented Graphs that Factor into Triangles
Discussiones Mathematicae Graph Theory, 2022 In 1987, Alavi, Boals, Chartrand, Erdős, and Oellermann conjectured that all graphs have an ascending subgraph decomposition (ASD). In a previous paper, Wagner showed that all oriented complete balanced tripartite graphs have an ASD.
Austin Andrea D., Wagner Brian C.
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Extremal Digraphs Avoiding Distinct Walks of Length 4 with the Same Endpoints
Discussiones Mathematicae Graph Theory, 2022 Let n ≥ 8 be an integer. We characterize the extremal digraphs of order n with the maximum number of arcs avoiding distinct walks of length 4 with the same endpoints.
Lyu Zhenhua
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Extremal digraphs on Meyniel-type condition for hamiltonian cycles in balanced bipartite digraphs [PDF]
Discrete Mathematics & Theoretical Computer Science, 2022 Let $D$ be a strong balanced digraph on $2a$ vertices. Adamus et al. have proved that $D$ is hamiltonian if $d(u)+d(v)\ge 3a$ whenever $uv\notin A(D)$ and $vu\notin A(D)$. The lower bound $3a$ is tight.
Ruixia Wang, Linxin Wu, Wei Meng
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Discussiones Mathematicae Graph Theory, 2022 We introduce a new notion of circular colourings for digraphs. The idea of this quantity, called star dichromatic number χ→*\vec \chi * (D) of a digraph D, is to allow a finer subdivision of digraphs with the same dichromatic number into such which are ...
Hochstättler Winfried, Steiner Raphael
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Hamiltonian Cycle Problem in Strong k-Quasi-Transitive Digraphs With Large Diameter
Discussiones Mathematicae Graph Theory, 2021 Let k be an integer with k ≥ 2. A digraph is k-quasi-transitive, if for any path x0x1... xk of length k, x0 and xk are adjacent. Let D be a strong k-quasi-transitive digraph with even k ≥ 4 and diameter at least k +2.
Wang Ruixia
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H-Kernels in Unions of H-Colored Quasi-Transitive Digraphs
Discussiones Mathematicae Graph Theory, 2021 Let H be a digraph (possibly with loops) and D a digraph without loops whose arcs are colored with the vertices of H (D is said to be an H-colored digraph). For an arc (x, y) of D, its color is denoted by c(x, y). A directed path W = (v0, . .
Campero-Alonzo José Manuel +1 more
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