New families of tripartite graphs with local antimagic chromatic number 3

Gee-Choon Lau1, Wai Chee Shiu2
177D, Jalan Suboh, 85000 Segamat, Johor, Malaysia
2Department of Mathematics, The Chinese University of Hong Kong, Shatin, Hong Kong, P.R. China

Abstract

For a graph \(G=(V,E)\) of size \(q\), a bijection \(f : E \to \{1,2,\ldots,q\}\) is a local antimagic labeling if it induces a vertex labeling \(f^+ : V \to \mathbb{N}\) such that \(f^+(u) \ne f^+(v)\), where \(f^+(u)\) is the sum of all the incident edge label(s) of \(u\), for every edge \(uv \in E(G)\). In this paper, we make use of matrices of fixed sizes to construct several families of infinitely many tripartite graphs with local antimagic chromatic number 3.

Keywords: local antimagic chromatic number, tripartite, regular, disconnected