What is the rank of the Kronecker product A⊗BA \otimes BA⊗B if rank(A)=r1\text{rank}(A) = r_1rank(A)=r1 and rank(B)=r2\text{rank}(B) = r_2rank(B)=r2?
r1r2r_1 r_2r1r2
r1+r2r_1 + r_2r1+r2
max(r1,r2)\max(r_1, r_2)max(r1,r2)
rank(A)⋅rank(B)\text{rank}(A) \cdot \text{rank}(B)rank(A)⋅rank(B)