{ "id": "1112.2607", "version": "v1", "published": "2011-12-12T16:26:41.000Z", "updated": "2011-12-12T16:26:41.000Z", "title": "Noise-induced drift in stochastic differential equations with arbitrary friction and diffusion in the Smoluchowski-Kramers limit", "authors": [ "Scott Hottovy", "Giovanni Volpe", "Jan Wehr" ], "comment": "11 pages, 5 figures", "journal": "Journal of Statistical Physics, 2012, Volume 146, Number 4, Pages 762-773", "doi": "10.1007/s10955-012-0418-9", "categories": [ "math-ph", "cond-mat.stat-mech", "math.MP" ], "abstract": "We consider the dynamics of systems with arbitrary friction and diffusion. These include, as a special case, systems for which friction and diffusion are connected by Einstein fluctuation-dissipation relation, e.g. Brownian motion. We study the limit where friction effects dominate the inertia, i.e. where the mass goes to zero (Smoluchowski-Kramers limit). {Using the It\\^o stochastic integral convention,} we show that the limiting effective Langevin equations has different drift fields depending on the relation between friction and diffusion. {Alternatively, our results can be cast as different interpretations of stochastic integration in the limiting equation}, which can be parametrized by $\\alpha \\in \\mathbb{R}$. Interestingly, in addition to the classical It\\^o ($\\alpha=0$), Stratonovich ($\\alpha=0.5$) and anti-It\\^o ($\\alpha=1$) integrals, we show that position-dependent $\\alpha = \\alpha(x)$, and even stochastic integrals with $\\alpha \\notin [0,1]$ arise. Our findings are supported by numerical simulations.", "revisions": [ { "version": "v1", "updated": "2011-12-12T16:26:41.000Z" } ], "analyses": { "keywords": [ "stochastic differential equations", "arbitrary friction", "smoluchowski-kramers limit", "noise-induced drift", "friction effects dominate" ], "tags": [ "journal article" ], "publication": { "journal": "Journal of Statistical Physics", "year": 2012, "month": "Jan", "pages": 5 }, "note": { "typesetting": "TeX", "pages": 11, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2012JSP...tmp....5H" } } }