Nonsurjective maps between rectangular matrix spaces preserving disjointness, triple products, or norms

Chi-Kwong Li, Ming-Cheng Tsai, Ya-Shu Wang +1

Let $M_{m,n}$ be the space of $m\times n$ real or complex rectangular matrices. Two matrices $A,B\in M_{m,n}$ are disjoint if $A^{\ast }B=0_n$ and $A{B}^{\ast }=0_m$. In this paper, a char…