{ "id": "1203.1640", "version": "v4", "published": "2012-03-07T21:35:53.000Z", "updated": "2013-12-09T21:03:21.000Z", "title": "A combinatorial description of the affine Gindikin-Karpelevich formula of type A_n^(1)", "authors": [ "Seok-Jin Kang", "Kyu-Hwan Lee", "Hansol Ryu", "Ben Salisbury" ], "comment": "20 pages; v2 Correction to the formula of Braverman, Finkelberg, and Kazhdan; v3 Minor correction; v4 Sage examples added", "categories": [ "math.RT", "math.CO" ], "abstract": "The classical Gindikin-Karpelevich formula appears in Langlands' calculation of the constant terms of Eisenstein series on reductive groups and in Macdonald's work on p-adic groups and affine Hecke algebras. The formula has been generalized in the work of Garland to the affine Kac-Moody case, and the affine case has been geometrically constructed in a recent paper of Braverman, Finkelberg, and Kazhdan. On the other hand, there have been efforts to write the formula as a sum over Kashiwara's crystal basis or Lusztig's canonical basis, initiated by Brubaker, Bump, and Friedberg. In this paper, we write the affine Gindikin-Karpelevich formula as a sum over the crystal of generalized Young walls when the underlying Kac-Moody algebra is of affine type A_n^(1). The coefficients of the terms in the sum are determined explicitly by the combinatorial data from Young walls.", "revisions": [ { "version": "v4", "updated": "2013-12-09T21:03:21.000Z" } ], "analyses": { "subjects": [ "17B37", "05E10" ], "keywords": [ "affine gindikin-karpelevich formula", "combinatorial description", "young walls", "kashiwaras crystal basis", "classical gindikin-karpelevich formula appears" ], "note": { "typesetting": "TeX", "pages": 20, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2012arXiv1203.1640K" } } }