{ "id": "2410.17125", "version": "v1", "published": "2024-10-22T15:59:37.000Z", "updated": "2024-10-22T15:59:37.000Z", "title": "Construction of irreducible $\\mathcal{U}(\\mathfrak{g})^{G'}$-modules and discretely decomposable restrictions", "authors": [ "Masatoshi Kitagawa" ], "comment": "42 pages", "categories": [ "math.RT" ], "abstract": "In this paper, we study the irreducibility of $\\mathcal{U}(\\mathfrak{g})^{G'}$-modules on the spaces of intertwining operators in the branching problem of reductive Lie algebras, and construct a family of finite-dimensional irreducible $\\mathcal{U}(\\mathfrak{g})^{G'}$-modules using the Zuckerman derived functors. We provide criteria for the irreducibility of $\\mathcal{U}(\\mathfrak{g})^{G'}$-modules in the cases of generalized Verma modules, cohomologically induced modules, and discrete series representations. We treat only discrete decomposable restrictions with certain dominance conditions (quasi-abelian and in the good range). To describe the $\\mathcal{U}(\\mathfrak{g})^{G'}$-modules, we give branching laws of cohomologically induced modules using ones of generalized Verma modules when $K'$ acts on $K/L_K$ transitively.", "revisions": [ { "version": "v1", "updated": "2024-10-22T15:59:37.000Z" } ], "analyses": { "keywords": [ "discretely decomposable restrictions", "generalized verma modules", "construction", "cohomologically induced modules", "discrete series representations" ], "note": { "typesetting": "TeX", "pages": 42, "language": "en", "license": "arXiv", "status": "editable" } } }