{ "id": "cond-mat/0306101", "version": "v1", "published": "2003-06-04T17:39:54.000Z", "updated": "2003-06-04T17:39:54.000Z", "title": "Persistence Exponents and the Statistics of Crossings and Occupation Times for Gaussian Stationary Processes", "authors": [ "George M. C. A. Ehrhardt", "Satya N. Majumdar", "Alan J. Bray" ], "comment": "35 pages, 31 figures", "journal": "Phys. Rev. E 69, 016106 (2004)", "doi": "10.1103/PhysRevE.69.016106", "categories": [ "cond-mat.stat-mech" ], "abstract": "We consider the persistence probability, the occupation-time distribution and the distribution of the number of zero crossings for discrete or (equivalently) discretely sampled Gaussian Stationary Processes (GSPs) of zero mean. We first consider the Ornstein-Uhlenbeck process, finding expressions for the mean and variance of the number of crossings and the `partial survival' probability. We then elaborate on the correlator expansion developed in an earlier paper [G. C. M. A. Ehrhardt and A. J. Bray, Phys. Rev. Lett. 88, 070602 (2001)] to calculate discretely sampled persistence exponents of GSPs of known correlator by means of a series expansion in the correlator. We apply this method to the processes d^n x/dt^n=\\eta(t) with n > 2, incorporating an extrapolation of the series to the limit of continuous sampling. We extend the correlator method to calculate the occupation-time and crossing-number distributions, as well as their partial-survival distributions and the means and variances of the occupation time and number of crossings. We apply these general methods to the d^n x/dt^n=\\eta(t) processes for n=1 (random walk), n=2 (random acceleration) and larger n, and to diffusion from random initial conditions in 1-3 dimensions. The results for discrete sampling are extrapolated to the continuum limit where possible.", "revisions": [ { "version": "v1", "updated": "2003-06-04T17:39:54.000Z" } ], "analyses": { "keywords": [ "occupation time", "persistence exponents", "distribution", "statistics", "correlator" ], "tags": [ "journal article" ], "publication": { "publisher": "APS", "journal": "Phys. Rev. E" }, "note": { "typesetting": "TeX", "pages": 35, "language": "en", "license": "arXiv", "status": "editable" } } }