Volume 35 • Number 1 • 2012   • On Sum-Connectivity Index of Bicyclic Graphs Zhibin Du and Bo Zhou Abstract. The sum-connectivity index is a new variant of the famous Randic connectivity index usable in quantitative structure-property relationship and quantitative structure-activity relationship studies. We determine the minimum sum-connectivity index of bicyclic graphs with $n$ vertices and matching number $m$, where $2\le m\le \lfloor n/2\rfloor$, the minimum and the second minimum, as well as the maximum and the second maximum sum-connectivity indices of bicyclic graphs with $n\ge 5$ vertices. The extremal graphs are characterized. 2010 Mathematics Subject Classification: 05C35, 05C90, 05C07. Full text: PDF