Results 21 to 30 of about 144 (108)
Forbidden Subgraphs for Collapsible Graphs and Supereulerian Graphs
Discussiones Mathematicae Graph Theory, 2022 In this paper, we completely characterize the connected forbidden subgraphs and pairs of connected forbidden subgraphs that force a 2-edge-connected (2-connected) graph to be collapsible.
Liu Xia, Xiong Liming
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Labeled Packing of Cycles and Circuits
Discussiones Mathematicae Graph Theory, 2022 In 2013, Duchçne, Kheddouci, Nowakowski and Tahraoui introduced a labeled version of the graph packing problem. It led to the introduction of a new graph parameter, the k-packing label-span λk.
Joffard Alice, Kheddouci Hamamache
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Hamilton Cycles in Double Generalized Petersen Graphs
Discussiones Mathematicae Graph Theory, 2019 Coxeter referred to generalizing the Petersen graph. Zhou and Feng modified the graphs and introduced the double generalized Petersen graphs (DGPGs). Kutnar and Petecki proved that DGPGs are Hamiltonian in special cases and conjectured that all DGPGs are
Sakamoto Yutaro
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Longer Cycles in Essentially 4-Connected Planar Graphs
Discussiones Mathematicae Graph Theory, 2020 A planar 3-connected graph G is called essentially 4-connected if, for every 3-separator S, at least one of the two components of G − S is an isolated vertex.
Fabrici Igor +3 more
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Long cycles in certain graphs of large degree
International Journal of Mathematics and Mathematical Sciences, Volume 24, Issue 10, Page 691-697, 2000., 2000 Let G be a connected graph of order n and X = {x ∈ V : d(x) ≥ n/2}. Suppose |X| ≥ 3 and G satisfies the modified Fan′s condition. We show that the vertices of the block B of G containing X form a cycle. This generalizes a result of Fan. We also give an efficient algorithm to obtain such a cycle. The complexity of this algorithm is O(n2). In case G is 2‐
Pak-Ken Wong
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Discussiones Mathematicae Graph Theory, 2021 Let G be either a complete graph of odd order or a complete bipartite graph in which each vertex partition has an even number of vertices. In this paper, we determine the set of triples (p, q, r), with p, q, r > 0, for which there exists a decomposition ...
Shyu Tay-Woei
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Longest cycles in certain bipartite graphs
International Journal of Mathematics and Mathematical Sciences, Volume 21, Issue 1, Page 103-106, 1998., 1995 Let G be a connected bipartite graph with bipartition (X, Y) such that |X| ≥ |Y|(≥2), n = |X| and m = |Y|. Suppose, for all vertices x ∈ X and y ∈ Y, dist(x, y) = 3 implies d(x) + d(y) ≥ n + 1. Then G contains a cycle of length 2m. In particular, if m = n, then G is hamiltomian.
Pak-Ken Wong
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Maps preserving matrices of extremal scrambling index
Special Matrices, 2018 In this paper we characterize surjective linear maps on matrices over antinegative semirings that preserve the set of matrices with maximal or minimal positive values of the scrambling index.
Guterman A.E., Maksaev A.M.
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Path decompositions of chains and circuits
International Journal of Mathematics and Mathematical Sciences, Volume 6, Issue 3, Page 521-533, 1983., 1983 Expressions for the path polynomials (see Farrell [1]) of chains and circuits are derived. These polynomials are then used to deduce results about node disjoint path decompositions of chains and circuits. Some results are also given for decompositions in which specific paths must be used.
E. J. Farrell
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On the Minimum Number of Spanning Trees in Cubic Multigraphs
Discussiones Mathematicae Graph Theory, 2020 Let G2n, H2n be two non-isomorphic connected cubic multigraphs of order 2n with parallel edges permitted but without loops. Let t(G2n), t (H2n) denote the number of spanning trees in G2n, H2n, respectively. We prove that for n ≥ 3 there is the unique G2n
Bogdanowicz Zbigniew R.
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