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arXiv 1907.07618math.PRmath.STstat.TH
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Ornstein-Uhlenbeck过程采样最大值的截断现象

Cut-off phenomenon for the maximum of a sampling of Ornstein-Uhlenbeck processes

Gerardo Barrera

AI总结:

本文研究由α指数稳定过程驱动的n个遍历Ornstein-Uhlenbeck过程采样的最大值过程的截断现象,证明高斯情形下存在轮廓截断、重尾情形下无截断。

摘要:

本文研究了当$n\to \infty$时,以$n\in \mathbb{N}$为索引的连续时间随机过程族在全变差距离下的所谓截断现象,该过程族为\\[ \left( \mathcal{Z}^{(n)}_t= \max\limits_{j\in \{1,\ldots,n\}}{X^{(j)}_t}:t\geq 0\right), \\]其中$X^{(1)},\ldots,X^{(n)}$是由指数为$α$的稳定过程驱动的$n$个遍历Ornstein-Uhlenbeck过程的采样。不难看出,对每个$n\in \mathbb{N}$,当$t$趋于无穷时,$\mathcal{Z}^{(n)}_t$在全变差距离下收敛于极限分布$\mathcal{Z}^{(n)}_\infty$。利用极值渐近理论,在高斯情形下我们证明,$\mathcal{Z}^{(n)}_t$的分布与其极限分布$\mathcal{Z}^{(n)}_\infty$之间的全变差距离,在截断时间附近的恒定时间窗内收敛于一个通用函数,这一事实在随机过程语境中被称为轮廓截断。另一方面,在重尾情形下我们证明不存在截断现象。

英文摘要:

In this article we study the so-called cut-off phenomenon in the total variation distance when $n\to \infty$ for the family of continuous-time stochastic processes indexed by $n\in \mathbb{N}$, \[ \left( \mathcal{Z}^{(n)}_t= \max\limits_{j\in \{1,\ldots,n\}}{X^{(j)}_t}:t\geq 0\right), \] where $X^{(1)},\ldots,X^{(n)}$ is a sampling of $n$ ergodic Ornstein-Uhlenbeck processes driven by stable processes of index $α$. It is not hard to see that for each $n\in \mathbb{N}$, $\mathcal{Z}^{(n)}_t$ converges in the total variation distance to a limiting distribution $\mathcal{Z}^{(n)}_\infty$ as $t$ goes by. Using the asymptotic theory of extremes; in the Gaussian case we prove that the total variation distance between the distribution of $\mathcal{Z}^{(n)}_t$ and its limiting distribution $\mathcal{Z}^{(n)}_\infty$ converges to a universal function in a constant time window around the cut-off time, a fact known as profile cut-off in the context of stochastic processes. On the other hand, in the heavy-tailed case we prove that there is not cut-off.

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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