On symmetric division deg index of trees with given parameters

Recently, the symmetric division deg ($ SDD $) index is proven to be a potentially useful molecular descriptor in QSAR and QSPR (quantitative structure-activity and structure-property relationships) studies. And its predictive capability is better than that of some popular topological indices, such as the famous geometric-arithmetic index and the second Zagreb index. In this work, the maximum $ SDD $ indices of trees with given matching number or domination number or independence number or number of pendant vertices or segments or diameter or radius are presented. Furthermore, the corresponding extremal trees are identified.