论文标题
Edgeworth型扩展KPZ固定点的单点分布,在先前的位置高度较大
Edgeworth-type expansion for the one-point distribution of the KPZ fixed point with a large height at a prior location
论文作者
论文摘要
储层计算是预测湍流的有力工具,其简单的架构具有处理大型系统的计算效率。然而,其实现通常需要完整的状态向量测量和系统非线性知识。我们使用非线性投影函数将系统测量扩展到高维空间,然后将其输入到储层中以获得预测。我们展示了这种储层计算网络在时空混沌系统上的应用,该系统模拟了湍流的若干特征。我们表明,使用径向基函数作为非线性投影器,即使只有部分观测并且不知道控制方程,也能稳健地捕捉复杂的系统非线性。最后,我们表明,当测量稀疏、不完整且带有噪声,甚至控制方程变得不准确时,我们的网络仍然可以产生相当准确的预测,从而为实际湍流系统的无模型预测铺平了道路。
We consider the Kardar-Parisi-Zhang (KPZ) fixed point $\mathrm{H}(x,τ)$ with the narrow-wedge initial condition and investigate the distribution of $\mathrm{H}(x,τ)$ conditioned on a large height at an earlier space-time point $\mathrm{H}(x',τ')$. As $\mathrm{H}(x',τ')$ tends to infinity, we prove that the conditional one-point distribution of $\mathrm{H}(x,τ)$ in the regime $τ>τ'$ converges to the Gaussian Unitary Ensemble (GUE) Tracy-Widom distribution and that the next two lower-order error terms can be expressed as derivatives of the Tracy-Widom distribution. The lowe order expansion here is analogue to the Edgeworth expansion in the central limit theorem. These KPZ-type limiting behaviors are different from the Gaussian-type ones obtained in \cite{Liu-Wang22} where they study the finite-dimensional distribution of $\mathrm{H}(x,τ)$ conditioned on a large height at a later space-time point $\mathrm{H}(x',τ')$. They show, with the narrow-wedge initial condition, that the conditional random field $\mathrm{H}(x,τ)$ in the regime $τ<τ'$ converges to the minimum of two independent Brownian bridges modified by linear drifts as $\mathrm{H}(x',τ')$ goes to infinity. The two results stated above provide the phase diagram of the asymptotic behaviors of a conditional law of KPZ fixed point in the regimes $τ>τ'$ and $τ<τ'$ when $\mathrm{H}(x',τ')$ goes to infinity.