{ "id": "1508.06763", "version": "v1", "published": "2015-08-27T09:19:24.000Z", "updated": "2015-08-27T09:19:24.000Z", "title": "Quantization commutes with singular reduction: cotangent bundles of compact Lie groups", "authors": [ "Jord Boeijink", "Klaas Landsman", "Walter van Suijlekom" ], "comment": "37 pages", "categories": [ "math-ph", "math.MP" ], "abstract": "We analyse the `quantization commutes with reduction' problem (first studied in physics by Dirac, and known in the mathematical literature also as the Guillemin-Sternberg Conjecture) for the conjugate action of a compact connected Lie group G on its own cotangent bundle T*G. This example is interesting because the momentum map is not proper and the ensuing symplectic (or Marsden-Weinstein quotient) T*G/Ad G is typically singular. In the spirit of (modern) geometric quantization, our quantization of T*G (with its standard Kaehler structure) is defined as the kernel of the Dolbeault-Dirac operator (or, alternatively, the spin Dirac operator) twisted by the pre-quantum line bundle. We show that this quantization of T*G reproduces the Hilbert space found earlier by Hall (2002) using geometric quantization based on a holomorphic polarisation. We then define the quantization of the singular quotient T*G/Ad G$ as the kernel of the (twisted) Dolbeault-Dirac operator on the principal stratum, and show that quantization commutes with reduction in the sense that either way one obtains the same Hilbert space L^2(T)^{W(G,T)}.", "revisions": [ { "version": "v1", "updated": "2015-08-27T09:19:24.000Z" } ], "analyses": { "subjects": [ "53D50", "81S10" ], "keywords": [ "compact lie groups", "quantization commutes", "cotangent bundle", "singular reduction", "hilbert space" ], "note": { "typesetting": "TeX", "pages": 37, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2015arXiv150806763B" } } }