{ "id": "1103.0034", "version": "v3", "published": "2011-02-28T21:45:26.000Z", "updated": "2013-07-05T15:39:58.000Z", "title": "On quantum mechanics with a magnetic field on R^n and on a torus T^n, and their relation", "authors": [ "Gaetano Fiore" ], "comment": "Latex2e file, 22 pages. Final version appeared in IJTP", "journal": "International Journal of Theoretical Physics 52 (2013), 877-896", "doi": "10.1007/s10773-012-1396-z", "categories": [ "math-ph", "hep-th", "math.MP", "quant-ph" ], "abstract": "We show in elementary terms the equivalence in a general gauge of a U(1)-gauge theory of a scalar charged particle on a torus T^n = R^n/L to the analogous theory on R^n constrained by quasiperiodicity under translations in the lattice L. The latter theory provides a global description of the former: the quasiperiodic wavefunctions defined on R^n play the role of sections of the associated hermitean line bundle E on T^n, since also E admits a global description as a quotient. The components of the covariant derivatives corresponding to a constant (necessarily integral) magnetic field B = dA generate a Lie algebra g_Q and together with the periodic functions the algebra of observables O_Q . The non-abelian part of g_Q is a Heisenberg Lie algebra with the electric charge operator Q as the central generator; the corresponding Lie group G_Q acts on the Hilbert space as the translation group up to phase factors. Also the space of sections of E is mapped into itself by g in G_Q . We identify the socalled magnetic translation group as a subgroup of the observables' group Y_Q . We determine the unitary irreducible representations of O_Q, Y_Q corresponding to integer charges and for each of them an associated orthonormal basis explicitly in con?guration space. We also clarify how in the n = 2m case a holomorphic structure and Theta functions arise on the associated complex torus. These results apply equally well to the physics of charged scalar particles on R^n and on T^n in the presence of periodic magnetic field B and scalar potential. They are also necessary preliminary steps for the application to these theories of the deformation procedure induced by Drinfel'd twists.", "revisions": [ { "version": "v3", "updated": "2013-07-05T15:39:58.000Z" } ], "analyses": { "subjects": [ "55R10", "55R91", "81S10", "53D50" ], "keywords": [ "magnetic field", "quantum mechanics", "global description", "necessary preliminary steps", "heisenberg lie algebra" ], "tags": [ "journal article" ], "publication": { "journal": "International Journal of Theoretical Physics", "year": 2013, "month": "Mar", "volume": 52, "number": 3, "pages": 877 }, "note": { "typesetting": "LaTeX", "pages": 22, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2013IJTP...52..877F", "inspire": 891036 } } }