Element deletion changes in dynamic coloring of graphs

A proper vertex k-coloring of a graph G is dynamic if for every vertex v with degree at least 2, the neighbors of v receive at least two different colors. The smallest integer k such that G has a dynamic k-coloring is the dynamic chromatic number χd(G). In this paper the differences between χd(G) and χd(G−e), and between χd(G) and χd(G−v) are investigated respectively.