On the adjacent vertex-distinguishing total colorings of some cubic graphs

Yun Feng1, Wensong Lin2
1School of Mathematics and Computer Science, Wuhan Polytechnic University, Wuhan 430023, PR China
2Department of Mathematics, Southeast University, Nanjing 210096, PR China

Abstract

Suppose \(G = (V, E)\) is a simple graph and \(f: (V\cup E) → {1,2,…, k}\) is a proper total k-coloring of G. Let \(C(u) = {f(u)} \cup {f(uv): uv \in E(G)}\) for each vertex u of G. The coloring f is said to be an adjacent vertex-distinguishing total coloring of G if \(C(u) \neq C(v)\) for every \(uv \in E(G)\). The minimum k for which such a chromatic number of G, and is denoted by \(X_at (G)\). This paper considers three types of cubic graphs: a specific family of cubic hasmiltonian graphs, snares and Generalized Petersen graphs. We prove that these cubic graphs have the same adjacent vertex-distinguishing total chromatic number 5. This is a step towards a problem that whether the bound \(X_at (G) ≤ 6\) is sharp for a graph G with maximum degree three.

Keywords: Adjacent vertex-distinguishing total coloring; Adjacent vertex-distinguishing total chromatic number; Cubic graphs; Snares; Generalized Petersen graphs