Counterbalancing steps at random in a random walk
Counterbalancing steps at random in a random walk
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随机游走中随机平衡步骤
DOI:
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发表时间:
2020
期刊:
影响因子:
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通讯作者:
J. Bertoin
中科院分区:
文献类型:
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作者:
J. Bertoin
A random walk with counterbalanced steps is a process of partial sums $check S(n)=check X_1+ cdots + check X_n$ whose steps $check X_n$ are given recursively as follows. For each $ngeq 2$, with a fixed probability $p$, $check X_n$ is a new independent sample from some fixed law $mu$, and with complementary probability $1-p$, $check X_n= -check X_{v(n)}$ counterbalances a previous step, with $v(n)$ a uniform random pick from ${1, ldots, n-1}$. We determine the asymptotic behavior of $check S(n)$ in terms of $p$ and the first two moments of $mu$. Our approach relies on a coupling with a reinforcement algorithm due to H.A. Simon, and on properties of random recursive trees and Eulerian numbers, which may be of independent interest. The method can be adapted to the situation where the step distribution $mu$ belongs to the domain of attraction of a stable law.