AN INTRODUCTION TO DISTANCE D MAGIC GRAPHS

Abstract: For a graph G of order jV (G)j = n and a real-valued mapping f : V (G) ! R, if S ⊂ V (G) then f(S) = Pw2S f(w) is called the weight of Sunder f. When there exists a bijection f : V (G) ! [n] such that the weight of allopen neighborhoods is the same, the graph is said to be 1-vertex magic, or Σ labeled. In this paper we generalize the notion of 1-vertex magic by defining a graph G of diameter d to be D-vertex magic when for D ⊂ f0; 1; : : : ; dg, we have that Pu2ND(v) f(u) is constant for all v 2 V (G). We provide several existence criteriafor graphs to be D-vertex magic and use them to provide solutions to several open problems presented at the IWOGL 2010 Conference. In addition, we extend the notion of vertex magic graphs by providing measures describing how close a non-vertex magic graph is to being vertex magic. The general viewpoint is to consider how to assign a set W of weights to the vertices so as to have an equitable distribution overthe D-neighborhoods.
Key words: Graph Labeling, vertex magic, Σ labeling, distance magic graphs, neighborhood sums
Author: Allen O’Neal, Peter J. Slater
Journal Code: jpmatematikagg110009

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