Total Chromatic Number of Folded Hypercubes

Meirun Chen1, Xiaofeng Guo2, Shaohui Zhai1
1Department of Mathematics and Physics, Xiamen University of Technology, Xiamen Fujian 361024, China
2School of Mathematical Sciences, Xiamen University, Xiamen Fujian 361005, China

Abstract

A total coloring of a simple graph \(G\) is a coloring of both the edges and the vertices. A total coloring is proper if no two adjacent or incident elements receive the same color.The minimum number of colors required for a proper total coloring of \(G\) is called the total chromatic number of \(G\) and denoted by \(\chi_t(G)\). The Total Coloring Conjecture (TCC) states that for every simple graph \(G\),\(\Delta(G) + 1 \leq \chi_t(G) \leq \Delta(G) + 2.\) \(G\) is called Type \(1\) (resp. Type \(2\)) if \(\chi_t(G) = \Delta(G) +1\) (resp. \(\chi_t(G) = \Delta(G) + 2\)). In this paper, we prove that the folded hypercubes \(FQ_n\), is of Type \(1\) when \(n \geq 4\).