On the Laplacian spectral radii of bicyclic graphs

A graph GG of order nn is called a bicyclic graph if GG is connected and the number of edges of GG is n+1n+1. Let B(n)B(n) be the set of all bicyclic graphs on nn vertices. In this paper, we obtain the first four largest Laplacian spectral radii among all the graphs in the class B(n)B(n) (n≥7n≥7) together with the corresponding graphs.