LetB(n, r) be the set of all bicyclic graphs with n vertices and r cut edges. In this paper we determine the unique graph with maximal adjacency spectral radius or signless Laplacian spectral radius among all graphs in B(n, r).

Identifying graphs with extremal properties is an extensively studied topic in spectral graph theory. In this paper, we study the log-concavity of a type iteration sequence related to α -normal weighted incidence matrices which presented by Lu and Man for computing radius hypergraphs. By using results obtained about method some edge operations, will characterize completely k -graphs smallest am...