{ "id": "2410.20183", "version": "v1", "published": "2024-10-26T13:44:57.000Z", "updated": "2024-10-26T13:44:57.000Z", "title": "A note on characters and endoscopy for $p$-adic $\\mathrm{SL}_2$", "authors": [ "Anne-Marie Aubert", "Roger Plymen" ], "comment": "21 pages", "categories": [ "math.RT", "math.NT" ], "abstract": "We consider the depth-zero supercuspidal $L$-packets of $\\mathrm{SL}_2$. With the aid of the classical character formulas of Sally-Shalika, we prove the endoscopic character identities. For the depth-zero $L$-packet of cardinality $4$, we find that, in order to comply with the Sally-Shalika formulas, the three endoscopic groups must be paired carefully with semisimple elements in the dual group $\\mathrm{PGL}_2(\\mathbb{C})$.", "revisions": [ { "version": "v1", "updated": "2024-10-26T13:44:57.000Z" } ], "analyses": { "subjects": [ "22E50" ], "keywords": [ "endoscopic character identities", "dual group", "semisimple elements", "endoscopic groups", "classical character formulas" ], "note": { "typesetting": "TeX", "pages": 21, "language": "en", "license": "arXiv", "status": "editable" } } }