{ "id": "1810.05386", "version": "v1", "published": "2018-10-12T07:36:51.000Z", "updated": "2018-10-12T07:36:51.000Z", "title": "Optimal lower bounds on hitting probabilities for non-linear systems of stochastic fractional heat equations", "authors": [ "Robert C. Dalang", "Fei Pu" ], "comment": "48 pages", "categories": [ "math.PR" ], "abstract": "We consider a system of $d$ non-linear stochastic fractional heat equations in spatial dimension $1$ driven by multiplicative $d$-dimensional space-time white noise. We establish a sharp Gaussian-type upper bound on the two-point probability density function of $(u(s, y), u (t, x))$. From this result, we deduce optimal lower bounds on hitting probabilities of the process $\\{u(t, x): (t, x) \\in [0, \\infty[ \\times \\mathbb{R}\\}$ in the non-Gaussian case, in terms of Newtonian capacity, which is as sharp as that in the Gaussian case. This also improves the result in Dalang, Khoshnevisan and Nualart [\\textit{Probab. Theory Related Fields} \\textbf{144} (2009) 371--424] for systems of classical stochastic heat equations. We also establish upper bounds on hitting probabilities of the solution in terms of Hausdorff measure.", "revisions": [ { "version": "v1", "updated": "2018-10-12T07:36:51.000Z" } ], "analyses": { "keywords": [ "hitting probabilities", "non-linear systems", "non-linear stochastic fractional heat equations", "deduce optimal lower bounds", "two-point probability density function" ], "note": { "typesetting": "TeX", "pages": 48, "language": "en", "license": "arXiv", "status": "editable" } } }