On the \(f\)-Chromatic Class of a Multi-Wheel Graph

Xia Zhang1, Yan Zhu2
1School of Mathematical Sciences, Shandong Normal University, Jinan 250014, P.R. China
2Department of Mathematics, East China University of Science and Technology, Shanghai 200237, P.R. China

Abstract

An \(f\)-coloring of a graph \(G\) is an edge-coloring of \(G\) such that each color appears at each vertex \(v \in V(G)\) at most \(f(v)\) times. A multi-wheel graph is a graph obtained from \(s\) cycles \(C_{n_1}, C_{n_2}, \ldots, C_{n_s}\) (\(s \geq 1\)) by adding a new vertex, say \(w\), and edges joining \(w\) to all the vertices of the \(s\) cycles. In this article, we solve a conjecture posed by Yu et al. in 2006 and prove that it is not always true. Furthermore, the classification problem of multi-wheel graphs on \(f\)-colorings is solved completely.