Spectral Statistics of ErdAs-R,nyi Graphs II: Eigenvalue Spacing and the Extreme Eigenvalues

We consider the ensemble of adjacency matrices of ErdAs-R,nyi random graphs, i.e. graphs on N vertices where every edge is chosen independently and with probability p a parts per thousand p(N). We rescale the matrix so that its bulk eigenvalues are of order one. Under the assumption , we prove the universality of eigenvalue distributions both in the bulk and at the edge of the spectrum. More precisely, we prove (1) that the eigenvalue spacing of the ErdAs-R,nyi graph in the bulk of the spectrum has the same distribution as that of the Gaussian orthogonal ensemble; and (2) that the second largest eigenvalue of the ErdAs-R,nyi graph has the same distribution as the largest eigenvalue of the Gaussian orthogonal ensemble. As an application of our method, we prove the bulk universality of generalized Wigner matrices under the assumption that the matrix entries have at least 4 + epsilon moments.