{ "id": "quant-ph/0410045", "version": "v1", "published": "2004-10-06T13:33:09.000Z", "updated": "2004-10-06T13:33:09.000Z", "title": "On the 'Polarized distances between quantum states and observables'", "authors": [ "D. A. Trifonov" ], "comment": "6 pages, Latex, 2 figures", "categories": [ "quant-ph" ], "abstract": "The scheme for construction of distances, presented in the previous paper quant-ph/0005087, v.1 (Ref. 1) is amended. The formulation of Proposition 1 of Ref. 1 does not ensure the triangle inequality, therefore some of the functionals D(a,b) in Ref. 1 are in fact quasi-distances. In this note we formulate sufficient conditions for a functional D(a,b) of the (squared) form D(a,b)^2 = f(a)^2 + f(b)^2 - 2f(a)f(b)g(a,b) to be a distance and provide some examples of such distances. A one parameter generalization of a bounded distance of the (squared) form D(a,b)^2 = D_0^2 (1 - g(a,b)), which includes the known Bures-Uhlmann and Hilbert-Schmidt distances between quantum states, is established.", "revisions": [ { "version": "v1", "updated": "2004-10-06T13:33:09.000Z" } ], "analyses": { "keywords": [ "quantum states", "polarized distances", "observables", "formulate sufficient conditions", "parameter generalization" ], "note": { "typesetting": "LaTeX", "pages": 6, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2004quant.ph.10045T" } } }