In this paper, we introduce some fundamental notions related to the so-called stochastic derivatives with respect to a given σ-field $\mathcal{Q}$ . In our framework, we recall well-known results about Markov–Wiener diffusions. We then focus mainly on the case where X is a fractional diffusion and where $\mathcal{Q}$ is the past, the future or the present of X. We treat some crucial examples and our main result is the existence of stochastic derivatives with respect to the present of X when X solves a stochastic differential equation driven by a fractional Brownian motion with Hurst index H>1/2. We give explicit formulas.
@article{1189000935,
author = {Darses, S\'ebastien and Nourdin, Ivan},
title = {Stochastic derivatives for fractional diffusions},
journal = {Ann. Probab.},
volume = {35},
number = {1},
year = {2007},
pages = { 1998-2020},
language = {en},
url = {http://dml.mathdoc.fr/item/1189000935}
}
Darses, Sébastien; Nourdin, Ivan. Stochastic derivatives for fractional diffusions. Ann. Probab., Tome 35 (2007) no. 1, pp. 1998-2020. http://gdmltest.u-ga.fr/item/1189000935/