摘要

An adjacent vertex distinguishing edge-coloring of a graph G is a proper edge coloring of G such that any pair of adjacent vertices are incident to distinct sets of colors. The minimum number of colors required for an adjacent vertex distinguishing edge-coloring of G is denoted by chi(a)'(G). Letmad(G) and Delta denote the maximum average degree and the maximum degree of a graph G, respectively. In this paper, we prove the following results: (1) If mad(G) < 3 and Delta >= 3, then chi(a)'(G) <= Delta + 2. (2) If mad(G) < 5/2 and Delta >= 4, or mad(G) < 7/3 and Delta >= 3, then chi(a)'(G) <= Delta + 1. (3) If mad(G) < 5/2 and Delta >= 5, then chi(a)'(G) = Delta+ 1 if and only if G contains adjacent vertices of maximum degree.