On the Maximum Sigma Index of k-Cyclic Graphs

Akbar Ali, Abeer M. Albalahi, Abdulaziz M. Alanazi +2

Let $G$ be a graph with edge set $E(G)$. Denote by $d_w$ the degree of a vertex $w$ of $G$. The sigma index of $G$ is defined as ${\sum }_{uv\in E(G)}(d_u-d_v{)}^2$. A connected graph o…