Neural Stochastic PDEs: Resolution-Invariant Learning of Continuous Spatiotemporal Dynamics
Cristopher SalviMaud LemercierAndris Gerasimovics
Introduces a neural architecture based on mild solutions of stochastic PDEs that learns solution operators from partially observed, continuously arriving data across arbitrary spatiotemporal resolutions up to three orders of magnitude faster than traditional numerical solvers.
Many complex natural and engineered systems—ranging from fluid turbulence and wave propagation to magnetic phase transitions—are subject to environmental fluctuations and are mathematically modeled using stochastic partial differential equations (SPDEs). Traditional numerical solvers for these equations require fine discretization grids to maintain accuracy and stability, which makes high-resolution simulations computationally intractable for time-sensitive decision-making and large-scale modeling. While recent physics-informed machine learning architectures attempt to approximate dynamical systems, existing methods either process temporal sequences without spatial resolution invariance or learn spatial mappings without accounting for continuous, external stochastic disturbances.
The article demonstrates the Neural Stochastic Partial Differential Equation (Neural SPDE) model, a novel deep learning architecture designed to learn the solution operators of continuous spatiotemporal systems driven by random noise from partially observed data. The authors evaluate whether this architecture can process inputs arriving at arbitrary spatial and temporal resolutions and generalize across different grid scales while maintaining high physical fidelity.
The approach models the mild solutions of randomly forced differential equations by operating in a latent functional space through frequency-domain kernel parameterizations. The model is evaluated via two distinct methods: a system of ordinary differential equations in Fourier space solved with standard integration tools, and a space-time fixed-point problem solved via root-finding iterations. The authors validated the framework on three benchmark physical systems: the 1D Ginzburg-Landau equation, the 1D Korteweg-De Vries equation, and the 2D stochastic Navier-Stokes equations under varying data volumes and subsampling conditions.
The findings show that the proposed model substantially outperforms existing baseline architectures across all physical benchmarks. When predicting dynamics conditioned on both initial states and random noise, the model achieved test errors of approximately 0.6% to 1.2% on Ginzburg-Landau dynamics and under 1% on the Korteweg-De Vries equation, outperforming alternatives by one to two orders of magnitude. For 2D Navier-Stokes turbulence, the model achieved a 4.9% relative error compared to 17.8% for the next best baseline, while demonstrating zero-shot super-resolution by training on a coarse 16x16 grid and accurately predicting on a fine 64x64 grid. Furthermore, the Neural SPDE executed inference up to 300 times faster than classical numerical solvers for Navier-Stokes equations and up to 80 times faster for wave equations.
These results indicate that data-driven surrogate models can drastically reduce computational overhead and simulation cycle times for complex, uncertain physical systems without sacrificing accuracy. For operational environments in engineering, meteorology, and fluid dynamics, this enables real-time forecasting, efficient sensitivity analysis, and rapid risk assessment using significantly smaller training datasets. Unlike prior neural operator methods, the framework successfully incorporates the impacts of external random signals on spatial fields.
Organizations developing surrogate physical models should consider adopting Neural SPDE architectures for spatiotemporal problems involving stochastic forcing. Implementation teams are advised to prioritize the fixed-point evaluation approach, which demonstrated approximately tenfold faster runtimes than the differential equation solver approach. Future technical development should explore non-Fourier spatial parameterizations to better handle complex, non-periodic geometries and investigate generative modeling frameworks for video and physical field generation.
While the empirical results demonstrate robust performance, users should exercise caution regarding temporal data resolution; the model's accuracy degrades when inputs are sparsely sampled in time due to the mathematical roughness of temporal driving noise. Additionally, current theoretical convergence guarantees are established for regularized noise under specific differential operators, meaning broader mathematical guarantees for arbitrary operators remain an open research problem.
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