{ "id": "1305.3325", "version": "v1", "published": "2013-05-14T23:51:23.000Z", "updated": "2013-05-14T23:51:23.000Z", "title": "On the spatial dynamics of the solution to the stochastic heat equation", "authors": [ "Sigurd Assing", "James Bichard" ], "comment": "36 pages", "categories": [ "math.PR", "math.AP" ], "abstract": "We consider the solution of $\\partial_t u=\\partial_x^2 u+\\partial_x\\partial_t B,\\,(x,t)\\in R\\times(0,\\infty)$, subject to $u(x,0)=0,\\,x\\in R$, where $B$ is a Brownian sheet. We show that $u$ also satisfies $\\partial_x^2 u +[\\,(-\\partial_t^2)^{1/2}+\\sqrt{2}\\partial_x(-\\partial_t^2)^{1/4}\\,]\\,u^a= \\partial_x\\partial_t{\\tilde B}$ in $R\\times(0,\\infty)$ where $u^a$ stands for the extension of $u(x,t)$ to $(x,t)\\in R^2$ which is antisymmetric in $t$ and $\\tilde{B}$ is another Brownian sheet. The new SPDE allows us to prove the strong Markov property of the pair $(u,\\partial_x u)$ when seen as a process indexed by $x\\ge x_0$, $x_0$ fixed, taking values in a state space of functions in $t$. The method of proof is based on enlargement of filtration and we discuss how our method could be applied to other quasi-linear SPDEs.", "revisions": [ { "version": "v1", "updated": "2013-05-14T23:51:23.000Z" } ], "analyses": { "subjects": [ "60H15" ], "keywords": [ "stochastic heat equation", "spatial dynamics", "brownian sheet", "strong markov property", "quasi-linear spdes" ], "note": { "typesetting": "TeX", "pages": 36, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2013arXiv1305.3325A" } } }