2 problems

Let $\mathcal{C}_d$ denote the set of circulant matrices, $\mathcal{U}_d$ the set of unistochastic matrices, and $\mathcal{C}_d^2$ the set of doubly circulant unistochastic matrice…

Let $\mathcal{L}_d$ be the set of bracelet matrices of dimension $d$. A monoid is a set closed under matrix multiplication and containing an identity element $\mathbb{I}_d$. Monoid…