{ "id": "1709.08986", "version": "v1", "published": "2017-09-26T12:55:45.000Z", "updated": "2017-09-26T12:55:45.000Z", "title": "Semi-simplicity of the category of admissible D-modules", "authors": [ "Gwyn Bellamy", "Magdalena Boos" ], "comment": "34 pages. Previously this was the second half of our article on \"The (cyclic) enhanced nilpotent cone via quiver representations\" arXiv:1609.04525 . The main result has been strengthened, and new material added", "categories": [ "math.RT" ], "abstract": "Using a representation theoretic parameterization for the orbits in the enhanced cyclic nilpotent cone, derived by the authors in a previous article, we compute the fundamental group of these orbits. This computation has several applications to the representation theory of the category of admissible $D$-modules on the space of representations of the framed cyclic quiver. First, and foremost, we compute precisely when this category is semi-simple. We also show that the category of admissible $D$-modules has enough projectives. Finally, the support of an admissible $D$-module is contained in a certain Lagrangian in the cotangent bundle of the space of representations. Thus, taking characteristic cycles defines a map from the $K$-group of the category of admissible $D$-modules to the $\\mathbb{Z}$-span of the irreducible components of this Lagrangian. We show that this map is always injective, and a bijection if and only if the monodromicity parameter is integral.", "revisions": [ { "version": "v1", "updated": "2017-09-26T12:55:45.000Z" } ], "analyses": { "keywords": [ "admissible d-modules", "semi-simplicity", "characteristic cycles defines", "enhanced cyclic nilpotent cone", "representation theoretic parameterization" ], "note": { "typesetting": "TeX", "pages": 34, "language": "en", "license": "arXiv", "status": "editable" } } }