Tuesday 6/6/6

Grassmannians. The Stiefel manifold. Orbits of N on the Grassmannian. Schubert varieties, which give a basis for homology. An intersection calculation in the cohomology ring of a Grassmannian. Factoid: the cohomology ring of the Grassmannian, with the Schubert basis, is isomorphic to the puzzle ring with its statuatory basis.