{ "id": "1511.00172", "version": "v1", "published": "2015-10-31T20:51:13.000Z", "updated": "2015-10-31T20:51:13.000Z", "title": "Broadband nature of power spectra for intermittent Maps with summable and nonsummable decay of correlations", "authors": [ "Georg A. Gottwald", "Ian Melbourne" ], "categories": [ "math.DS" ], "abstract": "We present results on the broadband nature of the power spectrum $S(\\omega)$, $\\omega\\in(0,2\\pi)$, for a large class of nonuniformly expanding maps with summable and nonsummable decay of correlations. In particular, we consider a class of intermittent maps $f:[0,1]\\to[0,1]$ with $f(x)\\approx x^{1+\\gamma}$ for $x\\approx 0$, where $\\gamma\\in(0,1)$. Such maps have summable decay of correlations when $\\gamma\\in(0,\\frac12)$, and $S(\\omega)$ extends to a continuous function on $[0,2\\pi]$ by the classical Wiener-Khintchine Theorem. We show that $S(\\omega)$ is typically bounded away from zero for H\\\"older observables. Moreover, in the nonsummable case $\\gamma\\in[\\frac12,1)$, we show that $S(\\omega)$ is defined almost everywhere with a continuous extension $\\tilde S(\\omega)$ defined on $(0,2\\pi)$, and $\\tilde S(\\omega)$ is typically nonvanishing.", "revisions": [ { "version": "v1", "updated": "2015-10-31T20:51:13.000Z" } ], "analyses": { "keywords": [ "intermittent maps", "broadband nature", "power spectrum", "nonsummable decay", "correlations" ], "publication": { "doi": "10.1088/1751-8113/49/17/174003", "journal": "Journal of Physics A Mathematical General", "year": 2016, "month": "Apr", "volume": 49, "number": 17, "pages": 174003 }, "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2016JPhA...49q4003G" } } }