{ "id": "2410.13519", "version": "v1", "published": "2024-10-17T13:08:26.000Z", "updated": "2024-10-17T13:08:26.000Z", "title": "Schubert cells and Whittaker functionals for $\\text{GL}(n,\\mathbb{R})$ part I: Combinatorics", "authors": [ "Doyon Kim" ], "comment": "33 pages", "categories": [ "math.RT", "math.NT" ], "abstract": "We give a formula for a birational map on the Schubert cell associated to each Weyl group element of $G=\\text{GL}(n)$. The map simplifies the UDL decomposition of matrices, providing structural insight into the Schubert cell decomposition of the flag variety $G/B$, where $B$ is a Borel subgroup. An application of the formula includes a new proof of the existence of Whittaker functionals for principal series representations of $\\text{GL}(n,\\mathbb{R})$ via integration by parts. In this paper, we establish combinatorial properties of the birational map and prove auxiliary results.", "revisions": [ { "version": "v1", "updated": "2024-10-17T13:08:26.000Z" } ], "analyses": { "subjects": [ "11F70", "05E14" ], "keywords": [ "whittaker functionals", "combinatorics", "birational map", "schubert cell decomposition", "principal series representations" ], "note": { "typesetting": "TeX", "pages": 33, "language": "en", "license": "arXiv", "status": "editable" } } }