{ "id": "2204.10480", "version": "v1", "published": "2022-04-22T03:39:20.000Z", "updated": "2022-04-22T03:39:20.000Z", "title": "Restricting Representations from a Complex Group to a Real Form", "authors": [ "Lucas Mason-Brown" ], "comment": "Comments are welcome!", "categories": [ "math.RT" ], "abstract": "Let $G$ be a complex connected reductive algebraic group and let $G_{\\mathbb{R}}$ be a real form of $G$. We construct a sequence of functors $L_i\\mathcal{R}$ from admissible (resp. finite-length) representations of $G$ to admissible (resp. finite-length) representations of $G_{\\mathbb{R}}$. We establish many basic properties of these functors, including their behavior with respect to infinitesimal character, associated variety, and restriction to a maximal compact subgroup. We deduce that each $L_i\\mathcal{R}$ takes unipotent representations of $G$ to unipotent representations of $G_{\\mathbb{R}}$. Taking the alternating sum of $L_i\\mathcal{R}$, we get a well-defined homomorphism on the level of characters. We compute this homomorphism in the case when $G_{\\mathbb{R}}$ is split.", "revisions": [ { "version": "v1", "updated": "2022-04-22T03:39:20.000Z" } ], "analyses": { "subjects": [ "22E46" ], "keywords": [ "real form", "complex group", "restricting representations", "unipotent representations", "complex connected reductive algebraic group" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }