Completely positive semidefinite rank

Anupam Prakash, Jamie Sikora, Antonios Varvitsiotis +1

An $n\times n$ matrix $X$ is called completely positive semidefinite (cpsd) if there exist $d\times d$ Hermitian positive semidefinite matrices $\{P_i{\}}_{i=1}^n$ (for some $d\ge 1$…