{ "id": "math/0411127", "version": "v1", "published": "2004-11-06T05:07:10.000Z", "updated": "2004-11-06T05:07:10.000Z", "title": "On Ideal Generators for Affine Schubert Varieties", "authors": [ "V. Kreiman", "V. Lakshmibai", "P. Magyar", "J. Weyman" ], "comment": "34 pages", "categories": [ "math.AG", "math.AC", "math.CO" ], "abstract": "We consider a certain class of Schubert varieties of the affine Grassmannian of type A. By embedding a Schubert variety into a finite-dimensional Grassmannian, we construct an explicit basis of sections of the basic line bundle by restricting certain Pl\\\"ucker co-ordinates. As a consequence, we write an explicit set of generators for the degree-one part of the ideal of the finite-dimensional embedding. This in turn gives a set of generators for the degree-one part of the ideal defining the affine Grassmannian inside the infinite Grassmannian which we conjecture to be a complete set of ideal generators. We apply our results to the orbit closures of nilpotent matrices. We describe (in a characteristic-free way) a filtration for the coordinate ring of a nilpotent orbit closure and state a conjecture on the SL(n)-module structures of the constituents of this filtration.", "revisions": [ { "version": "v1", "updated": "2004-11-06T05:07:10.000Z" } ], "analyses": { "subjects": [ "14M15" ], "keywords": [ "schubert variety", "affine schubert varieties", "ideal generators", "degree-one part", "affine grassmannian inside" ], "note": { "typesetting": "TeX", "pages": 34, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2004math.....11127K" } } }