{ "id": "math/0407330", "version": "v5", "published": "2004-07-19T19:43:33.000Z", "updated": "2006-03-09T19:55:54.000Z", "title": "Martingales, endomorphisms, and covariant systems of operators in Hilbert space", "authors": [ "Dorin Ervin Dutkay", "Palle E. T. Jorgensen" ], "comment": "44 pages, LaTeX2e (\"jotart\" document class); v2: A few opening paragraphs were added to the paper; an addition where a bit of the history is explained, and where some more relevant papers are cited. Corrected a typographical error in Proposition 8.1. v3: A few minor additions: More motivation and explanations in the Intro; Remark 3.3 is new; and eleven relevant references/citations are added; v4: corrected and updated bibliography; v5: more bibliography updates and change of LaTeX document class", "journal": "J. Operator Theory 58 (2007), no. 2, 269--310.", "categories": [ "math.CA", "math.OA" ], "abstract": "We show that a class of dynamical systems induces an associated operator system in Hilbert space. The dynamical systems are defined from a fixed finite-to-one mapping in a compact metric space, and the induced operators form a covariant system in a Hilbert space of L^2-martingales. Our martingale construction depends on a prescribed set of transition probabilities, given by a non-negative function. Our main theorem describes the induced martingale systems completely. The applications of our theorem include wavelets, the dynamics defined by iterations of rational functions, and sub-shifts in symbolic dynamics. In the theory of wavelets, in the study of subshifts, in the analysis of Julia sets of rational maps of a complex variable, and, more generally, in the study of dynamical systems, we are faced with the problem of building a unitary operator from a mapping r in a compact metric space X. The space X may be a torus, or the state space of subshift dynamical systems, or a Julia set. While our motivation derives from some wavelet problems, we have in mind other applications as well; and the issues involving covariant operator systems may be of independent interest.", "revisions": [ { "version": "v5", "updated": "2006-03-09T19:55:54.000Z" } ], "analyses": { "subjects": [ "42A16", "43A65", "42A65", "47C15", "33C50", "42C15", "42C40", "46E22", "47B32", "60J15", "60G42" ], "keywords": [ "hilbert space", "covariant system", "compact metric space", "julia set", "endomorphisms" ], "tags": [ "journal article" ], "note": { "typesetting": "LaTeX", "pages": 44, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2004math......7330E" } } }