Convex Polyhedra of Doubly Stochastic Matrices III. Affine and Combinatorial Properties of Omegan

Abstract Affine and combinatorial properties of the polytope Ω n of all n × n nonnegative doubly stochastic matrices are investigated. One consequence of this investigation is that if F is a face of Ω n of dimension d > 2, then F has at most 3( d −1) facets. The special faces of Ω n which were characterized in Part I of our study of Ω n in terms of the corresponding (0, 1)- matrices are classified with respect to affine equivalence.