English

First-passage times over moving boundaries for asymptotically stable walks

Probability 2018-01-15 v1

Abstract

Let {Sn,n1}\{S_n, n\geq1\} be a random walk wih independent and identically distributed increments and let {gn,n1}\{g_n,n\geq1\} be a sequence of real numbers. Let TgT_g denote the first time when SnS_n leaves (gn,)(g_n,\infty). Assume that the random walk is oscillating and asymptotically stable, that is, there exists a sequence {cn,n1}\{c_n,n\geq1\} such that Sn/cnS_n/c_n converges to a stable law. In this paper we determine the tail behaviour of TgT_g for all oscillating asymptotically stable walks and all boundary sequences satisfying gn=o(cn)g_n=o(c_n). Furthermore, we prove that the rescaled random walk conditioned to stay above the boundary up to time nn converges, as nn\to\infty, towards the stable meander.

Keywords

Cite

@article{arxiv.1801.04136,
  title  = {First-passage times over moving boundaries for asymptotically stable walks},
  author = {Denis Denisov and Alexander Sakhanenko and Vitali Wachtel},
  journal= {arXiv preprint arXiv:1801.04136},
  year   = {2018}
}

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20 pages