{ "id": "0706.4069", "version": "v2", "published": "2007-06-27T16:45:41.000Z", "updated": "2008-06-16T05:45:08.000Z", "title": "An effective criterion and a new example for ballistic diffusions in random environment", "authors": [ "Laurent Goergen" ], "comment": "Published in at http://dx.doi.org/10.1214/07-AOP354 the Annals of Probability (http://www.imstat.org/aop/) by the Institute of Mathematical Statistics (http://www.imstat.org)", "journal": "Annals of Probability 2008, Vol. 36, No. 3, 1093-1133", "doi": "10.1214/07-AOP354", "categories": [ "math.PR" ], "abstract": "In the setting of multidimensional diffusions in random environment, we carry on the investigation of condition $(T')$, introduced by Sznitman [Ann. Probab. 29 (2001) 723--764] and by Schmitz [Ann. Inst. H. Poincar\\'{e} Probab. Statist. 42 (2006) 683--714] respectively in the discrete and continuous setting, and which implies a law of large numbers with nonvanishing limiting velocity (ballistic behavior) as well as a central limit theorem. Specifically, we show that when $d\\geq2$, $(T')$ is equivalent to an effective condition that can be checked by local inspection of the environment. When $d=1$, we prove that condition $(T')$ is merely equivalent to almost sure transience. As an application of the effective criterion, we show that when $d\\geq4$ a perturbation of Brownian motion by a random drift of size at most $\\epsilon>0$ whose projection on some direction has expectation bigger than $\\epsilon^{2-\\eta},\\eta>0$, satisfies condition $(T')$ when $\\epsilon$ is small and hence exhibits ballistic behavior. This class of diffusions contains new examples of ballistic behavior which in particular do not fulfill the condition in [Ann. Inst. H. Poincar\\'{e} Probab. Statist. 42 (2006) 683--714], (5.4) therein, related to Kalikow's condition.", "revisions": [ { "version": "v2", "updated": "2008-06-16T05:45:08.000Z" } ], "analyses": { "subjects": [ "60K37", "82D30" ], "keywords": [ "random environment", "effective criterion", "ballistic diffusions", "ballistic behavior", "central limit theorem" ], "tags": [ "journal article" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2007arXiv0706.4069G" } } }