2,424 research outputs found

    On the Integer-antimagic Spectra of Non-Hamiltonian Graphs

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    Let AA be a nontrivial abelian group. A connected simple graph G=(V,E)G = (V, E) is AA-\textbf{antimagic} if there exists an edge labeling f:E(G)A{0}f: E(G) \to A \setminus \{0\} such that the induced vertex labeling f+:V(G)Af^+: V(G) \to A, defined by f+(v)=Σf^+(v) = \Sigma {f(u,v):(u,v)E(G)}\{f(u,v): (u, v) \in E(G) \}, is a one-to-one map. In this paper, we analyze the group-antimagic property for Cartesian products, hexagonal nets and theta graphs

    Good potentials for almost isomorphism of countable state Markov shifts

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    Almost isomorphism is an equivalence relation on countable state Markov shifts which provides a strong version of Borel conjugacy; still, for mixing SPR shifts, entropy is a complete invariant of almost isomorphism. In this paper, we establish a class of potentials on countable state Markov shifts whose thermodynamic formalism is respected by almost isomorphism

    Pseudo-magic graphs

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    AbstractWe characterize graphs for which there is a labeling of the edges by pairwise different integer labels such that the sum of the labels of the edges incident with a vertex is independent of the particular vertex. We generalize to mixed graphs, and to labelings with values in an integral domain

    D4-Magic Graphs

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    Consider the set X = {1, 2, 3, 4} with 4 elements. A permutation of X is a function from X to itself that is both one one and on to. The permutations of X with the composition of functions as a binary operation is a nonabelian group, called the symmetric group S 4 . Now consider the collection of all permutations corresponding to the ways that two copies of a square with vertices 1, 2, 3 and 4 can be placed one covering the other with vertices on the top of vertices. This collection form a nonabelian subgroup of S 4 , called the dihedral group D 4 . In this paper, we introduce A-magic labelings of graphs, where A is a finite nonabelian group and investigate graphs that are D 4 -magic. This did not attract much attention in the literature
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