2 problems

Let $C_{M,N}$ be the space of partial complex Hadamard matrices, let $D_{M,N}$ be its dephased quotient, and for $Hin C_{M,N}$ write $d(H)=\dim(\widetilde{T}_H C_{M,N})$ for its un…

Let $U$ be a unitary matrix with a fixed Kronecker product structure, meaning that the sequence of sizes of its Kronecker factors is fixed up to order. In either of the two cases c…