2 problems

Let $\mathbb{M}_{G}$ be the vector space of matrices of a fixed dimension $N$ which have all state symmetries $\rho\in G$. A permutation group $G$ is a pure matrix state-symmetry g…

Let $A$ and $B$ be Hermitian matrices and let $\Pi$ be a matrix implementing the symmetry relations … Suppose that $A$ and $B$ almost commute. Symmetry-preserving Lin conjecture. T…