{ "id": "1707.02178", "version": "v1", "published": "2017-07-07T13:56:17.000Z", "updated": "2017-07-07T13:56:17.000Z", "title": "Applying Parabolic Peterson: Affine Algebras and the Quantum Cohomology of the Grassmannian", "authors": [ "Jonathan Cookmeyer", "Elizabeth Milićević" ], "comment": "38 pages, most figures best viewed in color", "categories": [ "math.CO", "math.AG" ], "abstract": "The Peterson isomorphism relates the homology of the affine Grassmannian to the quantum cohomology of any flag variety. In the case of a partial flag, Peterson's map is only a surjection, and one needs to quotient by a suitable ideal on the affine side to map isomorphically onto the quantum cohomology. We provide a detailed exposition of this parabolic Peterson isomorphism in the case of the Grassmannian of m-planes in complex n-space, including an explicit recipe for doing quantum Schubert calculus in terms of the appropriate subset of non-commutative k-Schur functions. As an application, we recast Postnikov's affine approach to the quantum cohomology of the Grassmannian as a consequence of parabolic Peterson by showing that the affine nilTemperley-Lieb algebra arises naturally when forming the requisite quotient of the homology of the affine Grassmannian.", "revisions": [ { "version": "v1", "updated": "2017-07-07T13:56:17.000Z" } ], "analyses": { "subjects": [ "14M15", "05E05", "20F55", "14N15", "14N35" ], "keywords": [ "quantum cohomology", "applying parabolic peterson", "affine algebras", "affine grassmannian", "affine niltemperley-lieb algebra arises" ], "note": { "typesetting": "TeX", "pages": 38, "language": "en", "license": "arXiv", "status": "editable" } } }