3 problems

Let $\mathbf{H} \in \mathbb{R}^{n\times n}$ be a positive definite Hankel matrix with bit complexity $\ell$ and condition number bounded by $2^\ell$. An inverse symmetric positive…

Let $b>1$, and set … For each $n$, let $M_b(n)$ denote the largest absolute value of an entry of the inverse Vandermonde matrix, and let $c_{i,j,n}$ denote its entries. Diagonal-ma…

Let $n \geq 3$ and let $S(\alpha,m)=\alpha I_n+m\mathbf{1}_n\mathbf{1}_n^\top$. A symmetric diagonally dominant matrix $J$ is assumed to satisfy $0<J\leq S(\alpha,m)$. Inverse infi…