Local law and Tracy–Widom limit for sparse random matrices

Abstract

We consider spectral properties and the edge universality of sparse random matrices, the class of random matrices that includes the adjacency matrices of the Erdős–Renyi graph model G(N, p). We prove a local law for the eigenvalue density up to the spectral edges. Under a suitable condition on the sparsity, we also prove that the rescaled extremal eigenvalues exhibit GOE Tracy–Widom fluctuations if a deterministic shift of the spectral edge due to the sparsity is included. For the adjacency matrix of the Erdős–Renyi graph this establishes the Tracy–Widom fluctuations of the second largest eigenvalue when p is much larger than $$N^{-2/3}$$ with a deterministic shift of order $$(Np)^{-1}$$ .