English

Hiding a drift

Probability 2009-12-09 v4

Abstract

In this article we consider a Brownian motion with drift of the form dSt=μtdt+dBt\qquadfort0,dS_t=\mu_t dt+dB_t\qquadfor t\ge0, with a specific nontrivial (μt)t0(\mu_t)_{t\geq0}, predictable with respect to FB\mathbb{F}^B, the natural filtration of the Brownian motion B=(Bt)t0B=(B_t)_{t\ge0}. We construct a process H=(Ht)t0H=(H_t)_{t\ge0}, also predictable with respect to FB\mathbb{F}^B, such that ((HS)t)t0((H\cdot S)_t)_{t\ge 0} is a Brownian motion in its own filtration. Furthermore, for any δ>0\delta>0, we refine this construction such that the drift (μt)t0(\mu_t)_{t\ge0} only takes values in ]μδ,μ+δ[]\mu-\delta,\mu+\delta[, for fixed μ>0\mu>0.

Keywords

Cite

@article{arxiv.0802.1152,
  title  = {Hiding a drift},
  author = {Miklós Rásonyi and Walter Schachermayer and Richard Warnung},
  journal= {arXiv preprint arXiv:0802.1152},
  year   = {2009}
}

Comments

Published in at http://dx.doi.org/10.1214/09-AOP469 the Annals of Probability (http://www.imstat.org/aop/) by the Institute of Mathematical Statistics (http://www.imstat.org)

R2 v1 2026-06-21T10:10:51.982Z