Electronic Journal of Graph Theory and Applications (EJGTA)
Vol 12, No 1 (2024): Electronic Journal of Graph Theory and Applications

Properly even harmonious labeling of a union of stars

Henderson, Zachary M. (University of Minnesota - Duluth)



Article Info

Publish Date
20 Apr 2024

Abstract

A function f is defined as an even harmonious labeling on a graph G with q edges if f : V(G)→{0, 1, …, 2q} is an injection and the induced function f* : E(G)→{0, 2, …, 2(q − 1)} defined by f*(uv)=f(u)+f(v) (mod2q) is bijective. A properly even harmonious labeling is an even harmonious labeling in which the codomain of f is {0, 1, …, 2q − 1}, and a strongly harmonious labeling is an even harmonious labeling that also satisfies the additional condition that for any two adjacent vertices with labels u and v, 0 < u + v ≤ 2q. In , Gallian and Schoenhard proved that Sn1 ∪ Sn2 ∪ … ∪ Snt is strongly even harmonious for n1 ≥ n2 ≥ … ≥ nt and t < n1/2 + 2. In this paper, we begin with the related question “When is the graph of k n-star components, G = kSn, properly even harmonious?" We conclude that kSn is properly even harmonious if and only if k is even or k is odd, k > 1, and n ≥ 2. We also conclude that Sn1 ∪ Sn2 ∪ … ∪ Snk is properly even harmonious when k ≥ 2, ni ≥ 2 for all i and give some additional results on combinations of star and banana graphs.

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Journal Info

Abbrev

ejgta

Publisher

Subject

Electrical & Electronics Engineering

Description

The Electronic Journal of Graph Theory and Applications (EJGTA) is a refereed journal devoted to all areas of modern graph theory together with applications to other fields of mathematics, computer science and other sciences. The journal is published by the Indonesian Combinatorial Society ...