{ "id": "1404.2990", "version": "v3", "published": "2014-04-11T02:54:25.000Z", "updated": "2014-10-11T03:05:52.000Z", "title": "Gradient Estimates and Applications for SDEs in Hilbert Space with Multiplicative Noise and Log-Hölder Drif", "authors": [ "Feng-Yu Wang" ], "comment": "37 pages", "categories": [ "math.PR" ], "abstract": "Consider the stochastic evolution equation in a separable Hilbert space $\\H$ with a nice multiplicative noise and a locally log-H\\\"older continuous drift $b: [0,\\infty)\\times \\H\\to \\H,$ i.e. for any $n\\ge 1$ there exists a constant $K_n>0$ such that $$|b_t(x)-b_t(y)|^2 \\le \\ff{K_n}{\\log (\\e + |x-y|^{-1})},\\ \\ \\ t\\in [0,n], x,y\\in \\H, |x|\\lor |y|\\le n.$$ We prove that for any initial data the equation has a unique (possibly explosive) mild solution. Under a reasonable condition ensuring the non-explosion of the solution, the strong Feller property of the associated Markov semigroup is proved. Gradient estimates and log-Harnack inequalities are derived for the associated semigroup under certain global conditions, which are new even in finite-dimensions.", "revisions": [ { "version": "v2", "updated": "2014-05-08T09:41:21.000Z", "comment": "35 pages", "journal": null, "doi": null }, { "version": "v3", "updated": "2014-10-11T03:05:52.000Z" } ], "analyses": { "keywords": [ "gradient estimates", "log-hölder drif", "applications", "stochastic evolution equation", "strong feller property" ], "note": { "typesetting": "TeX", "pages": 37, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2014arXiv1404.2990W" } } }