Computing the nc-rank via discrete convex optimization on CAT(0) spaces

Masaki Hamada, Hiroshi Hirai

In this paper, we address the noncommutative rank (nc-rank) computation of a linear symbolic matrix \[ A = A_1 x_1 + A_2 x_2 + \cdots + A_m x_m, \] where each $A_i$ is an $n \times…