فهرست نشریات علمی دسترسی آزاد ایران

The symmetric division deg index (or simply SDD) was proposed by Vukicevic et al. as a remarkable predictor of total surface area of polychlorobiphenyls. We are interested in how the SDD of a graph changes when edges are deleted. The obtained results show that all cases are possible: increased, decreased and unchanged. In this article, we present some necessary conditions for the occurrence of each of the three different states.