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Some Processes Associated with Fractional Bessel Processes

Probability 2007-05-23 v1

Abstract

Let B={(Bt1,...,Btd),t0}B=\{(B_{t}^{1},..., B_{t}^{d}), t\geq 0\} be a dd-dimensional fractional Brownian motion with Hurst parameter HH and let Rt=R_{t}=% \sqrt{(B_{t}^{1})^{2}+... +(B_{t}^{d})^{2}} be the fractional Bessel process. It\^{o}'s formula for the fractional Brownian motion leads to the equation Rt=i=1d0tBsiRs R_{t}=\sum_{i=1}^{d}\int_{0}^{t}\frac{B_{s}^{i}}{R_{s}}% dB_{s}^{i}+H(d-1)\int_{0}^{t}\frac{s^{2H-1}}{R_{s}}ds . In the Brownian motion case (H=1/2H=1/2), X_{t}=\sum_{i=1}^{d}\int_{0}^{t} frac{B_{s}^{i}}{% R_{s}}dB_{s}^{i} is a Brownian motion. In this paper it is shown that XtX_{t} is \underbar{not} a fractional Brownian motion if H1/2H\not=1/2. We will study some other properties of this stochastic process as well.

Keywords

Cite

@article{arxiv.math/0402019,
  title  = {Some Processes Associated with Fractional Bessel Processes},
  author = {Yaozhong Hu and David Nualart},
  journal= {arXiv preprint arXiv:math/0402019},
  year   = {2007}
}