{ "id": "math/0608334", "version": "v1", "published": "2006-08-14T12:27:32.000Z", "updated": "2006-08-14T12:27:32.000Z", "title": "On the correlation measure of a family of commuting Hermitian operators with applications to particle densities of the quasi-free representations of the CAR and CCR", "authors": [ "Eugene Lytvynov", "Lin Mei" ], "categories": [ "math.PR", "math-ph", "math.MP" ], "abstract": "Let $X$ be a locally compact, second countable Hausdorff topological space. We consider a family of commuting Hermitian operators $a(\\Delta)$ indexed by all measurable, relatively compact sets $\\Delta$ in $X$ (a quantum stochastic process over $X$). For such a family, we introduce the notion of a correlation measure. We prove that, if the family of operators possesses a correlation measure which satisfies some condition of growth, then there exists a point process over $X$ having the same correlation measure. Furthermore, the operators $a(\\Delta)$ can be realized as multiplication operators in the $L^2$-space with respect to this point process. In the proof, we utilize the notion of $\\star$-positive definiteness, proposed in [Y. G. Kondratiev and T.\\ Kuna, {\\it Infin. Dimens. Anal. Quantum Probab. Relat. Top.} {\\bf 5} (2002), 201--233]. In particular, our result extends the criterion of existence of a point process from that paper to the case of the topological space $X$, which is a standard underlying space in the theory of point processes. As applications, we discuss particle densities of the quasi-free representations of the CAR and CCR, which lead to fermion, boson, fermion-like, and boson-like (e.g. para-fermions and para-bosons of order 2) point processes. In particular, we prove that any fermion point process corresponding to a Hermitian kernel may be derived in this way.", "revisions": [ { "version": "v1", "updated": "2006-08-14T12:27:32.000Z" } ], "analyses": { "subjects": [ "47B15", "60G55", "81S05", "81S25" ], "keywords": [ "correlation measure", "commuting hermitian operators", "quasi-free representations", "particle densities", "point process" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2006math......8334L" } } }