Topological properties of orthostochastic matrices

The set of n×n orthostochastic matrices with the topology induced by the Euclidean matric is shown to be compact and path-connected. For n<3, the set of orthostochastic matrices is identical to the set of doubly stochastic matrices. In this paper, it is shown that for n3 the orthostochastic matrices are not everywhere dense in the set of doubly stochastic matrices, thus answering a question of L. Mirsky in his survey article on doubly stochastic matrices [2].