English

$L^p$ uniform random walk-type approximation for fractional Brownian motion with Hurst exponent $0 < H < \frac{1}{2}$

Probability 2021-01-12 v3

Abstract

In this note, we prove an LpL^p uniform approximation of the fractional Brownian motion with Hurst exponent 0<H<120 < H < \frac{1}{2} by means of a family of continuous-time random walks imbedded on a given Brownian motion. The approximation is constructed via a pathwise representation of the fractional Brownian motion in terms of a standard Brownian motion. For an arbitrary choice ϵk\epsilon_k for the size of the jumps of the family of random walks, the rate of convergence of the approximation scheme is O(ϵkp(12λ)+2(δ1))O(\epsilon_k^{p(1-2\lambda)+ 2(\delta-1)}) whenever max{0,1pH2}<δ<1\max\{0,1-\frac{pH}{2}\}< \delta < 1, λ(1H2,12+δ1p)\lambda \in \big(\frac{1-H}{2}, \frac{1}{2} + \frac{\delta-1}{p}\big).

Keywords

Cite

@article{arxiv.2007.15472,
  title  = {$L^p$ uniform random walk-type approximation for fractional Brownian motion with Hurst exponent $0 < H < \frac{1}{2}$},
  author = {Alberto Ohashi and Francys A. de Souza},
  journal= {arXiv preprint arXiv:2007.15472},
  year   = {2021}
}

Comments

Version to appear in Electronic Communications in Probability. A Lemma concerning an L^p estimate for the mesh is added in the published version. The proof of the pathwise representation was simplified