{ "id": "1504.01508", "version": "v1", "published": "2015-04-07T07:56:01.000Z", "updated": "2015-04-07T07:56:01.000Z", "title": "Stochastic averaging for multiscale Markov processes with an application to branching random walk in random environment", "authors": [ "Martin Hutzenthaler", "Peter Pfaffelhuber" ], "comment": "18 pages", "categories": [ "math.PR" ], "abstract": "Let $Z = (Z_t)_{t\\in[0,\\infty)}$ be an ergodic Markov process and, for $n\\in\\mathbb{N}$, let $Z^n = (Z_{n^2 t})_{t\\in[0,\\infty)}$ drive a process $X^n$. Classical results show under suitable conditions that the sequence of non-Markovian processes $(X^n)_{n\\in\\mathbb{N}}$ converges to a Markov process and give its infinitesimal characteristics. Here, we consider a general sequence $(Z^n)_{n\\in\\mathbb{N}}$. Using a general result on stochastic averaging from [Kur92], we derive conditions which ensure that the sequence $(X^n)_{n\\in\\mathbb{N}}$ converges as in the classical case. As an application, we consider the diffusion limit of branching random walk in quickly evolving random environment.", "revisions": [ { "version": "v1", "updated": "2015-04-07T07:56:01.000Z" } ], "analyses": { "subjects": [ "60F05" ], "keywords": [ "branching random walk", "multiscale markov processes", "stochastic averaging", "application", "ergodic markov process" ], "note": { "typesetting": "TeX", "pages": 18, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2015arXiv150401508H" } } }