Index of Hadamard multiplication by positive matrices II

G. Corach, D. Stojanoff

Given a definite nonnegative matrix $A\in M_n(C)$, we study the minimal index of A: $I(A)=\max \{\lambda \ge 0:A\circ B\ge \lambda B$ for all $0\le B\}$, where $A\circ B$ denotes the Hada…