Explicit formulae for time-space Brownian chaos
Peccati, Giovanni
Bernoulli, Tome 9 (2003) no. 3, p. 25-48 / Harvested from Project Euclid
Let $F$ be a square-integrable and infinitely weakly differentiable functional of a standard Brownian motion $X$: we show that the $n$th integrand in the time-space chaotic decomposition of $F$ has the form $\mathbb{E}\lambdaeft(\alphapha _{\lambdaeft( n\right)}D^{n}F\mid X_{t_{1}},\rm dots,X_{t_{n}}\right)$, where $\alphapha _{\lambdaeft( n\right)}$ is a transform of Hardy type and $D^{n}$ denotes the $n$th derivative operator. In this way, we complete the results of previous papers, and provide a time-space counterpart to the classic Stroock formulae for Wiener chaos. Our main tool is an extension of the Clark--Ocone formula in the context of initially enlarged filtrations. We discuss an application to the static hedging of path-dependent options in a continuous-time financial model driven by $X$. A formal connection between our results and the orthogonal decomposition of the space of square-integrable functionals of a standard Brownian bridge -- as proved by Gosselin and Wurzbacher -- is also established.
Publié le : 2003-02-14
Classification:  Brownian bridge,  Brownian motion,  Clark-Ocone formula,  enlargement of filtrations,  Hardy operators,  static hedging,  Stroock's formula,  time-space chaos
@article{1068129009,
     author = {Peccati, Giovanni},
     title = {Explicit formulae for time-space Brownian chaos},
     journal = {Bernoulli},
     volume = {9},
     number = {3},
     year = {2003},
     pages = { 25-48},
     language = {en},
     url = {http://dml.mathdoc.fr/item/1068129009}
}
Peccati, Giovanni. Explicit formulae for time-space Brownian chaos. Bernoulli, Tome 9 (2003) no. 3, pp.  25-48. http://gdmltest.u-ga.fr/item/1068129009/