{ "id": "1603.03902", "version": "v1", "published": "2016-03-12T12:38:50.000Z", "updated": "2016-03-12T12:38:50.000Z", "title": "The transition density of Brownian motion killed on a bounded set", "authors": [ "Kohei Uchiyama" ], "comment": "21 pages", "categories": [ "math.PR" ], "abstract": "We study the transition density of a standard two-dimensional Brownian motion killed when hitting a bounded Borel set $A$. We derive the asymptotic form of the density, say $p^A_t({\\bf x},{\\bf y})$, for large times $t$ and for ${\\bf x}$ and ${\\bf y}$ in the exterior of $A$ valid uniformly under the constraint $|{\\bf x}|\\vee |{\\bf y}| =O(t)$. Within the parabolic regime $|{\\bf x}|\\vee |{\\bf y}| = O(\\sqrt t)$ in particular $p^A_t({\\bf x},{\\bf y})$ is shown to behave like $4e_A({\\bf x})e_A({\\bf y}) (\\lg t)^{-2} p_t({\\bf y}-{\\bf x})$ for large $t$, where $p_t({\\bf y}-{\\bf x})$ is the transition kernel of the Brownian motion (without killing) and $e_A$ is the Green function for the \\lq exterior of $A$' with a pole at infinity normalized so that $e_A({\\bf x}) \\sim \\lg |{\\bf x}|$. We also provide fairly accurate upper and lower bounds of $p^A_t({\\bf x},{\\bf y})$ for the case $|{\\bf x}|\\vee |{\\bf y}|>t$ as well as corresponding results for the higher dimensions.", "revisions": [ { "version": "v1", "updated": "2016-03-12T12:38:50.000Z" } ], "analyses": { "keywords": [ "transition density", "bounded set", "standard two-dimensional brownian motion", "borel set", "asymptotic form" ], "note": { "typesetting": "TeX", "pages": 21, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2016arXiv160303902U" } } }