Xianya Geng

Spectral radius and Hamiltonicity in generalized split graphs

A graph G ˆ is a split graph if its vertex set can be partitioned into a clique S and an independent set I , and the cross edges join a vertex in S to a vertex in I . A generalized split graph G is obtained from the split graph G ˆ by replacing each vertex v of I with a clique S...

On the Sum of the Second Zagreb Index and Its Reciprocal Index for Tricyclic Graphs

For a simple connected graph G, let dG(u) denote the degree of a vertex u. The second Zagreb index Z2(G)=∑uv∈E(G)dG(u)dG(v) and its reciprocal index mZ2(G)=∑uv∈E(G)1/(dG(u)dG(v)) are widely studied topological indices in graph theory. Their sum Z2(G)+Z2m(G) has been studied for t...