Spectra of Graphs and Closed Distance Magic Labelings

TL;DR

This paper explores the relationship between the spectra of graphs and closed distance magic labelings, analyzing algebraic properties, specific graph families, and a related number theoretic problem.

Contribution

It establishes connections between graph spectra and closed distance magic labelings, and applies these results to various graph products and circulant graphs.

Findings

Relations between spectra and labelings are characterized.

Closed distance magic labelings are identified for certain graph products.

A number theoretic problem leads to new families of such graphs.

Abstract

Let $G=(V,E)$ be a graph of order $n$. A closed distance magic labeling of $G$ is a bijection $\ell \colon V(G)\rightarrow \{1,\ldots ,n\}$ for which there exists a positive integer $k$ such that $\sum_{x\in N[v]}\ell (x)=k$ for all $v\in V $, where $N[v]$ is the closed neighborhood of $v$. We consider the closed distance magic graphs in the algebraic context. In particular we analyze the relations between the closed distance magic labelings and the spectra of graphs. These results are then applied to the strong product of graphs with complete graph or cycle and to the circulant graphs. We end with a number theoretic problem whose solution results in another family of closed distance magic graphs somewhat related to the strong product.