On the general sum-connectivity index of tricyclic graphs

The general sum-connectivity index of a graph G is a molecular descriptor defined as χ _α(G)=∑ _uv∈ E(G)(d_G(u)+d_G(v))^α , where d_G(u) denotes the degree of vertex u in G and α is a real number. In this paper, we obtain the first third graphs with maximum general sum-connectivity index among the connected tricyclic graphs of order n for α≥ 1 by four transformations which increase the general sum-connectivity index.