{ "id": "1703.04091", "version": "v1", "published": "2017-03-12T10:00:17.000Z", "updated": "2017-03-12T10:00:17.000Z", "title": "Self-adjoint extensions and unitary operators on the boundary", "authors": [ "Paolo Facchi", "Giancarlo Garnero", "Marilena Ligabò" ], "comment": "16 pages", "categories": [ "math-ph", "math.MP", "quant-ph" ], "abstract": "We establish a bijection between the self-adjoint extensions of the Laplace operator on a bounded regular domain and the unitary operators on the boundary. Each unitary encodes a specific relation between the boundary value of the function and its normal derivative. This bijection sets up a characterization of all physically admissible dynamics of a nonrelativistic quantum particle confined in a cavity. More- over, this correspondence is discussed also at the level of quadratic forms. Finally, the connection between this parametrization of the extensions and the classical one, in terms of boundary self-adjoint operators on closed subspaces, is shown.", "revisions": [ { "version": "v1", "updated": "2017-03-12T10:00:17.000Z" } ], "analyses": { "subjects": [ "81Q10", "35J25", "47A07" ], "keywords": [ "unitary operators", "self-adjoint extensions", "nonrelativistic quantum particle", "boundary self-adjoint operators", "unitary encodes" ], "note": { "typesetting": "TeX", "pages": 16, "language": "en", "license": "arXiv", "status": "editable" } } }