{ "id": "1804.03701", "version": "v1", "published": "2018-04-10T19:59:34.000Z", "updated": "2018-04-10T19:59:34.000Z", "title": "Catalan functions and $k$-Schur positivity", "authors": [ "Jonah Blasiak", "Jennifer Morse", "Anna Pun", "Daniel Summers" ], "comment": "43 pages, 2 figures", "categories": [ "math.CO", "math.QA" ], "abstract": "We prove that graded $k$-Schur functions are $G$-equivariant Euler characteristics of vector bundles on the flag variety, settling a conjecture of Chen-Haiman. We expose a new miraculous shift invariance property of the graded $k$-Schur functions and resolve the Schur positivity and $k$-branching conjectures in the strongest possible terms by providing direct combinatorial formulas using strong marked tableaux.", "revisions": [ { "version": "v1", "updated": "2018-04-10T19:59:34.000Z" } ], "analyses": { "subjects": [ "05E05", "14N15", "05A30", "33D52" ], "keywords": [ "schur positivity", "catalan functions", "schur functions", "direct combinatorial formulas", "miraculous shift invariance property" ], "note": { "typesetting": "TeX", "pages": 43, "language": "en", "license": "arXiv", "status": "editable" } } }