{ "id": "1608.02175", "version": "v1", "published": "2016-08-07T02:40:53.000Z", "updated": "2016-08-07T02:40:53.000Z", "title": "Precise large deviations of the first passage time", "authors": [ "Dariusz Buraczewski", "Mariusz Maślanka" ], "comment": "10 pages", "categories": [ "math.PR" ], "abstract": "Let $S_n$ be partial sums of an i.i.d. sequence $\\{X_i\\}$. We assume that $\\mathbb{E} X_1 <0$ and $\\mathbb{P}[X_1>0]>0$. In this paper we study the first passage time $$ \\tau_u = \\inf\\{n:\\; S_n > u\\}. $$ The classical Cram\\'er's estimate of the ruin probability says that $$ \\mathbb{P}[\\tau_u<\\infty] \\sim C e^{-\\alpha_0 u}\\quad \\text{as } u\\to \\infty, $$ for some parameter $\\alpha_0$. The aim of the paper is to describe precise large deviations of the first crossing by $S_n$ a linear boundary, more precisely for a fixed parameter $\\rho$ we study asymptotic behavior of $\\mathbb{P}\\left[\\tau_u = \\lfloor u/\\rho\\rfloor \\right]$ as $u$ tends to infinity.", "revisions": [ { "version": "v1", "updated": "2016-08-07T02:40:53.000Z" } ], "analyses": { "subjects": [ "60G50", "60F10" ], "keywords": [ "first passage time", "precise large deviations", "ruin probability says", "study asymptotic behavior", "classical cramers estimate" ], "note": { "typesetting": "TeX", "pages": 10, "language": "en", "license": "arXiv", "status": "editable" } } }