University of KashanIranian Journal of Mathematical Chemistry2228-64895220141101Upper and Lower Bounds of Symmetric Division Deg Index9198735710.22052/ijmc.2014.7357ENAlexanderVasilyevUniversity of Primorska, IAMJournal Article20140702Symmetric Division Deg index is one of the 148 discrete Adriatic indices that showed good predictive properties on the testing sets provided by International Academy of Mathematical Chemistry. Symmetric Division Deg index is defined by $$ SDD(G) = sumE left( frac{min{d_u,d_v}}{max{d_u,d_v}} + frac{max{d_u,d_v}}{min{d_u,d_v}} right), $$ where $d_i$ is the degree of vertex $i$ in graph $G$. In this paper we provide lower and upper bounds of SDD index in some classes of graphs and determine the corresponding extremal graphs.https://ijmc.kashanu.ac.ir/article_7357_78bfab656717a8a35de2906a6ca46a99.pdf