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arXiv 1108.3602math.PR
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布朗运动非光滑变换间二次协变的小噪声估计

Small Noise Estimates of the Quadratic Covariation between Non-smooth Transformations of Brownian Motion

Sergio A. Almada Monter

摘要:

给定一个布朗运动$W$,本文研究了当$f$不光滑时,$f (\eps W)$与$W$的二次协变差作为$\eps \to 0$的渐近性态.发现的主要特征之一是,在$f \in C^α$的情况下,衰减速度在$\eps$中是多项式的,而不是预期的指数。我们使用一个最近的表示作为$[f (\eps W), W]$的向后-向前Itô积分来证明一个$\eps$依赖的近似方案,这是独立的兴趣。我们通过提供对这个近似的估计来得到结果。

英文摘要:

Given a Brownian Motion $W$, in this paper we study the asymptotic behavior, as $\eps \to 0$, of the quadratic covariation between $f (\eps W)$ and $W$ in the case in which $f$ is not smooth. Among the main features discovered is that the speed of the decay in the case $f \in C^α$ is polynomial in $\eps$ and not exponential as expected. We use a recent representation as a backward- forward Itô integral of $[f (\eps W), W]$ to prove an $\eps$-dependent approximation scheme which is of independent interest. We get the result by providing estimates to this approximation.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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