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Fluctuations of stochastic PDEs with long-range correlations

Luca Gerolla, Martin Hairer, Xue-Mei Li

TL;DR

This paper analyzes the large-scale fluctuations of a nonlinear stochastic heat equation in $d\ge 3$ subjected to long-range, non-integrable spatial noise with covariance decaying as $|x|^{-\kappa}$, $\kappa\in(2,d)$. By combining Malliavin calculus with Stein’s method and a Feynman-diagram framework, the authors show that diffusively scaled fluctuations persist in the limit and converge to an additive stochastic heat equation driven by a spatially colored noise with Riesz kernel $|x-y|^{-\kappa}$, with an effective variance $\nu_{\text{eff}}^2=|\mathbb{E}[\sigma(Z(0))]|^2$. They establish both finite-dimensional distribution convergence and tightness in negative Hölder spaces, and provide detailed bounds via diagrammatic estimates to control residual terms. The results extend the Edwards–Wilkinson-type limits to long-range correlated noise and quantify how correlation decay controls the scaling and effective variance, highlighting persistent spatial structure in the limit. This contributes to a deeper understanding of SPDE fluctuations under nonlocal spatial correlations and the robustness of Gaussian fluctuation limits beyond compactly supported noise.

Abstract

We study the large-scale dynamics of the solution to a nonlinear stochastic heat equation (SHE) in dimensions $d \geq 3$ with long-range dependence. This equation is driven by multiplicative Gaussian noise, which is white in time and coloured in space with non-integrable spatial covariance that decays at the rate of $|x|^{-κ}$ at infinity, where $κ\in (2, d)$. Inspired by recent studies on SHE and KPZ equations driven by noise with compactly supported spatial correlation, we demonstrate that the correlations persist in the large-scale limit. The fluctuations of the diffusively scaled solution converge to the solution of a stochastic heat equation with additive noise whose correlation is the Riesz kernel of degree $-κ$. Moreover, the fluctuations converge as a distribution-valued process in the optimal Hölder topologies.

Fluctuations of stochastic PDEs with long-range correlations

TL;DR

This paper analyzes the large-scale fluctuations of a nonlinear stochastic heat equation in subjected to long-range, non-integrable spatial noise with covariance decaying as , . By combining Malliavin calculus with Stein’s method and a Feynman-diagram framework, the authors show that diffusively scaled fluctuations persist in the limit and converge to an additive stochastic heat equation driven by a spatially colored noise with Riesz kernel , with an effective variance . They establish both finite-dimensional distribution convergence and tightness in negative Hölder spaces, and provide detailed bounds via diagrammatic estimates to control residual terms. The results extend the Edwards–Wilkinson-type limits to long-range correlated noise and quantify how correlation decay controls the scaling and effective variance, highlighting persistent spatial structure in the limit. This contributes to a deeper understanding of SPDE fluctuations under nonlocal spatial correlations and the robustness of Gaussian fluctuation limits beyond compactly supported noise.

Abstract

We study the large-scale dynamics of the solution to a nonlinear stochastic heat equation (SHE) in dimensions with long-range dependence. This equation is driven by multiplicative Gaussian noise, which is white in time and coloured in space with non-integrable spatial covariance that decays at the rate of at infinity, where . Inspired by recent studies on SHE and KPZ equations driven by noise with compactly supported spatial correlation, we demonstrate that the correlations persist in the large-scale limit. The fluctuations of the diffusively scaled solution converge to the solution of a stochastic heat equation with additive noise whose correlation is the Riesz kernel of degree . Moreover, the fluctuations converge as a distribution-valued process in the optimal Hölder topologies.
Paper Structure (17 sections, 29 theorems, 32 equations)

This paper contains 17 sections, 29 theorems, 32 equations.

Key Result

Theorem 1.3

Let $d\geqslant 3$, $\sigma$ be Lipschitz continuous, and suppose that $\xi$ satisfies Assumption assump-noise. Then, there exists a $\beta_0>0$ such that for all $\beta < \beta_0$, and for any time indices $0 < t_1 \leqslant \dots \leqslant t_n$, and for any smooth functions with compact support $\ Here, $\mathcal{U}$ denotes the solution to the additive stochastic heat equation with effective v

Theorems & Definitions (72)

  • Example 1.2
  • Theorem 1.3
  • Remark 1.4
  • Remark 1.5
  • Theorem 1.6
  • Remark 1.7
  • Remark 1.8
  • Remark 1.9
  • Lemma 2.1
  • proof
  • ...and 62 more