Invertibility of symmetric random matrices
Abstract
We study n by n symmetric random matrices H, possibly discrete, with iid above-diagonal entries. We show that H is singular with probability at most exp(-nc), and the spectral norm of the inverse of H is O(sqrtn). Furthermore, the spectrum of H is delocalized on the optimal scale o(n-1/2). These results improve upon a polynomial singularity bound due to Costello, Tao and Vu, and they generalize, up to constant factors, results of Tao and Vu, and Erdos, Schlein and Yau.
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