On the Structures of \(V_{4}\)-Magic and \(\mathcal{Z}_{4}\)-Magic Graphs

J.P. Georges1, D.W. Mauro1, Yan Wang2
1Trinity College Trinity College Hartford, CT USA 06013 Hartford, CT USA 06013
2Millsaps College Jackson, MS USA 39210

Abstract

This paper settles in the negative the following open question: Are \( V_4 \)-magic graphs necessarily \( \mathbb{Z}_4 \)-magic? For an abelian group \( A \), we examine the properties of \( A \)-magic labelings with constant weight \( 0 \), called \emph{zero-sum \( A \)-magic}, and utilize well-known results on edge-colorings in order to construct (from \( 3 \)-regular graphs) infinite families that are \( V_4 \)-magic but not \( \mathbb{Z}_4 \)-magic. Noting that our arguments lead to connected graphs of order \( 2n \) for all \( n \geq 11 \) that are \( V_4 \)-magic and not \( \mathbb{Z}_4 \)-magic, we conclude the paper by investigating the zero-sum integer-magic spectra of graphs, including Cartesian products, and give a conjecture about the zero-sum integer-magic spectra of \( 3 \)-regular graphs.