{ "id": "1010.3781", "version": "v1", "published": "2010-10-19T02:40:00.000Z", "updated": "2010-10-19T02:40:00.000Z", "title": "On the change of root numbers under twisting and applications", "authors": [ "Ariel Pacetti" ], "comment": "15 pages", "categories": [ "math.NT" ], "abstract": "The purpose of this article is to show how the root number of a modular form changes by twisting in terms of the local Weil-Deligne representation at each prime ideal. As an application, we show how one can for each odd prime $p$, determine whether a modular form (or a Hilbert modular form) with trivial nebentypus is Steinberg, Principal Series or Supercuspidal at $p$ by analyzing the change of sign under a suitable twist. We also explain the case $p=2$, where twisting is not enough in general.", "revisions": [ { "version": "v1", "updated": "2010-10-19T02:40:00.000Z" } ], "analyses": { "subjects": [ "11F70" ], "keywords": [ "root number", "application", "local weil-deligne representation", "modular form changes", "hilbert modular form" ], "note": { "typesetting": "TeX", "pages": 15, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2010arXiv1010.3781P" } } }