English

Hitting times of Bessel processes

Probability 2011-06-08 v2

Abstract

Let T1(μ)T_1^{(\mu)} be the first hitting time of the point 1 by the Bessel process with index μR\mu\in \R starting from x>1x>1. Using an integral formula for the density qx(μ)(t)q_x^{(\mu)}(t) of T1(μ)T_1^{(\mu)}, obtained in Byczkowski, Ryznar (Studia Math., 173(1):19-38, 2006), we prove sharp estimates of the density of T1(μ)T_1^{(\mu)} which exibit the dependence both on time and space variables. Our result provides optimal estimates for the density of the hitting time of the unit ball by the Brownian motion in Rn\mathbb{R}^n, which improve existing bounds. Another application is to provide sharp estimates for the Poisson kernel for half-spaces for hyperbolic Brownian motion in real hyperbolic spaces.

Keywords

Cite

@article{arxiv.1009.3513,
  title  = {Hitting times of Bessel processes},
  author = {Tomasz Byczkowski and Jacek Malecki and Michal Ryznar},
  journal= {arXiv preprint arXiv:1009.3513},
  year   = {2011}
}
R2 v1 2026-06-21T16:15:35.673Z