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arXiv 2311.09151math.PRmath-phmath.MP
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时空随机环境中随机游走的乘性SHE极限

Multiplicative SHE limit of random walks in space-time random environments

Sayan Das, Hindy Drillick, Shalin Parekh

AI总结:

本文证明在中等偏差缩放下,一维随机游走淬火密度的涨落由乘性噪声随机热方程(SHE)描述,且通过离散SPDE方法揭示了极限中产生独立噪声的非平凡现象。

摘要:

我们证明,在某种中等偏差缩放下,乘性噪声随机热方程(SHE)作为一维随机游走淬火密度的涨落出现,该游走的转移概率是iid [0,1]值的随机变量。与中等无序区中有向聚合物情形不同,在时空扩散重缩放下,我们的权重方差是固定的而非趋于零。因此,对该模型直接取混沌展开的极限会失败,并在极限中观察到非平凡的噪声系数。我们的证明未使用混沌技术,而是利用了在该区制下淬火密度求解一个类似于SHE的离散SPDE这一事实。作为技术的副产品,我们证明了极限中会产生独立噪声,即预极限噪声场不收敛到极限SPDE的驱动噪声。

英文摘要:

We show that under a certain moderate deviation scaling, the multiplicative-noise stochastic heat equation (SHE) arises as the fluctuations of the quenched density of a 1D random walk whose transition probabilities are iid [0,1]-valued random variables. In contrast to the case of directed polymers in the intermediate disorder regime, the variance of our weights is fixed rather than vanishing under the diffusive rescaling of space-time. Consequently, taking a naive limit of the chaos expansion fails for this model, and a nontrivial noise coefficient is observed in the limit. Rather than using chaos techniques, our proof instead uses the fact that in this regime the quenched density solves a discrete SPDE which resembles the SHE. As a byproduct of our techniques, it is shown that independent noise is generated in the limit, in the sense that the prelimiting noise field does not converge to the driving noise of the limiting SPDE.

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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