{ "id": "0710.3965", "version": "v2", "published": "2007-10-22T01:45:38.000Z", "updated": "2009-10-20T13:20:35.000Z", "title": "Quasisymmetric functions and Kazhdan-Lusztig polynomials", "authors": [ "Louis J. Billera", "Francesco Brenti" ], "comment": "27 pages. Final version: definitions reorganized for clarity, added Example 4.6 and two citations. To appear in Israel Journal of Mathematics", "categories": [ "math.CO", "math.RT" ], "abstract": "We associate a quasisymmetric function to any Bruhat interval in a general Coxeter group. This association can be seen to be a morphism of Hopf algebras to the subalgebra of all peak functions, leading to an extension of the cd-index of convex polytopes. We show how the Kazhdan-Lusztig polynomial of the Bruhat interval can be expressed in terms of this complete cd-index and otherwise explicit combinatorially defined polynomials. In particular, we obtain the simplest closed formula for the Kazhdan-Lusztig polynomials that holds in complete generality.", "revisions": [ { "version": "v2", "updated": "2009-10-20T13:20:35.000Z" } ], "analyses": { "subjects": [ "20F55", "05E99", "05E15" ], "keywords": [ "kazhdan-lusztig polynomial", "quasisymmetric function", "bruhat interval", "general coxeter group", "simplest closed formula" ], "note": { "typesetting": "TeX", "pages": 27, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2007arXiv0710.3965B" } } }