Descent-cycling in Schubert calculus.
We propose a theory of double Schubert polynomials for the Lie types , , which naturally extends the family of Lascoux and Schützenberger in type . These polynomials satisfy positivity, orthogonality and stability properties, and represent the classes of Schubert varieties and degeneracy loci of vector bundles. When is a maximal Grassmannian element of the Weyl group, can be expressed in terms of Schur-type determinants and Pfaffians, in analogy with the type formula of Kempf and Laksov....