Pretraining a Neural Operator in Lower Dimensions
This work addresses the data scarcity problem for researchers developing neural PDE solvers, offering an incremental but practical approach to reduce pretraining costs.
The paper tackles the high cost of data collection for pretraining neural PDE solvers by proposing a strategy to pretrain on lower-dimensional PDEs, where data is cheaper, and then transfer to higher dimensions, achieving competitive performance with reduced computational expense.
There has recently been increasing attention towards developing foundational neural Partial Differential Equation (PDE) solvers and neural operators through large-scale pretraining. However, unlike vision and language models that make use of abundant and inexpensive (unlabeled) data for pretraining, these neural solvers usually rely on simulated PDE data, which can be costly to obtain, especially for high-dimensional PDEs. In this work, we aim to Pretrain neural PDE solvers on Lower Dimensional PDEs (PreLowD) where data collection is the least expensive. We evaluated the effectiveness of this pretraining strategy in similar PDEs in higher dimensions. We use the Factorized Fourier Neural Operator (FFNO) due to having the necessary flexibility to be applied to PDE data of arbitrary spatial dimensions and reuse trained parameters in lower dimensions. In addition, our work sheds light on the effect of the fine-tuning configuration to make the most of this pretraining strategy. Code is available at https://github.com/BaratiLab/PreLowD.