U-cross Gram matrices and their invertibility

Invertibility of symmetric random matrices

We study n × n symmetric random matrices H, possibly discrete, with iid abovediagonal entries. We show that H is singular with probability at most exp(−nc), and ‖H−1‖ = O(√n). 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 T...

Full Sign-Invertibility and Symplectic Matrices

An n n sign pattern H is said to be sign-invertible if there exists a sign pattern H 1 (called the sign-inverse of H) such that, for all matrices A 2 Q(H), A 1 exists and A 1 2 Q(H 1). If, in addition, H 1 is sign-invertible (implying (H 1) 1 = H), H is said to be fully sign-invertible and (H;H 1) is called a sign-invertible pair. Given an n n sign pattern H, a Symplectic Pair in Q(H) is a pair...

Invertibility of Random Matrices Lecture Notes

Invertibility of Matrices of Field Elements

In this paper the theory of invertibility of matrices of field elements (see e.g. [5], [6]) is developed. The main purpose of this article is to prove that the left invertibility and the right invertibility are equivalent for a matrix of field elements. To prove this, we introduced a special transformation of matrix to some canonical forms. Other concepts as zero vector and base vectors of fiel...

Invertibility of Random Matrices: Unitary and Orthogonal Perturbations

We show that a perturbation of any fixed square matrix D by a random unitary matrix is well invertible with high probability. A similar result holds for perturbations by random orthogonal matrices; the only notable exception is when D is close to orthogonal. As an application, these results completely eliminate a hard-to-check condition from the Single Ring Theorem by Guionnet, Krishnapur and Z...