Let $A\in\Bbb{C}^{m\times n}$ be a complex $m\times n$ matrix such that $m>n$. We need to find the submatrix (by deleting rows) $B\in\Bbb{C}^{n\times n}$ of $A$ with the least $||B^{-1}||_{F}$.
I feel somehow we need to pick $n$ rows which are almost orthogonal to each other. Any ideas?