{ "id": "0901.1506", "version": "v3", "published": "2009-01-12T05:30:56.000Z", "updated": "2009-08-31T23:52:35.000Z", "title": "K-theory Schubert calculus of the affine Grassmannian", "authors": [ "Thomas Lam", "Anne Schilling", "Mark Shimozono" ], "comment": "38 pages", "journal": "Compositio Mathematica 146 Issue 4 (2010) 811-852", "doi": "10.1112/S0010437X09004539", "categories": [ "math.CO", "math.AG" ], "abstract": "We construct the Schubert basis of the torus-equivariant K-homology of the affine Grassmannian of a simple algebraic group G, using the K-theoretic NilHecke ring of Kostant and Kumar. This is the K-theoretic analogue of a construction of Peterson in equivariant homology. For the case G = SL_n, the K-homology of the affine Grassmannian is identified with a sub-Hopf algebra of the ring of symmetric functions. The Schubert basis is represented by inhomogeneous symmetric functions, called K-k-Schur functions, whose highest degree term is a k-Schur function. The dual basis in K-cohomology is given by the affine stable Grothendieck polynomials, verifying a conjecture of Lam. In addition, we give a Pieri rule in K-homology. Many of our constructions have geometric interpretations using Kashiwara's thick affine flag manifold.", "revisions": [ { "version": "v3", "updated": "2009-08-31T23:52:35.000Z" } ], "analyses": { "subjects": [ "05E05", "14N15" ], "keywords": [ "affine grassmannian", "k-theory schubert calculus", "kashiwaras thick affine flag manifold", "schubert basis", "symmetric functions" ], "tags": [ "journal article" ], "note": { "typesetting": "TeX", "pages": 38, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2009arXiv0901.1506L" } } }