On the lower bound of the spectral norm of symmetric random matrices with independent entries

Abstract

We show that the spectral radius of an $N\times N$ random symmetric matrix with i.i.d. bounded centered but non-symmetrically distributed entries is bounded from below by $ 2 \sigma - o( N^{-6/11+\varepsilon}), $ where $\sigma^2 $ is the variance of the matrix entries and $\varepsilon $ is an arbitrary small positive number. Combining with our previous result from [7], this proves that for any $\varepsilon <0, \ $ one has $ \|A_N\| =2 \sigma + o( N^{-6/11+\varepsilon}) $ with probability going to $ 1 $ as $N \to \infty$.