Enhancing training of physics-informed neural networks using domain-decomposition based preconditioning strategies
Alena Kopaničáková, Hardik Kothari, George Em Karniadakis, Rolf Krause
TL;DR
The paper tackles the slow and often ill-conditioned training of physics-informed neural networks (PINNs) by introducing nonlinear right preconditioning based on Schwarz domain decomposition. By decomposing network parameters into layer-wise subnetworks and solving local problems, the authors build additive (ASPQN) and multiplicative (MSPQN) preconditioners that yield a preconditioned system $\mathcal{F}(\boldsymbol{\theta}) = \nabla \mathcal{L}(G(\boldsymbol{\theta}))$ and improved global updates for $\mathcal{L}$. Empirical results on Burgers', diffusion-advection, Klein-Gordon, and Allen-Cahn problems show that SPQN methods significantly accelerate convergence and deliver more accurate PDE solutions than standard $\text{Adam}$ and $\text{L-BFGS}$, with ASPQN offering substantial model-parallel speedups. The work provides a scalable framework for PINN training that leverages parallel subnetworks and nonlinear preconditioning, with potential applicability to other deep-learning tasks beyond PINNs.
Abstract
We propose to enhance the training of physics-informed neural networks (PINNs). To this aim, we introduce nonlinear additive and multiplicative preconditioning strategies for the widely used L-BFGS optimizer. The nonlinear preconditioners are constructed by utilizing the Schwarz domain-decomposition framework, where the parameters of the network are decomposed in a layer-wise manner. Through a series of numerical experiments, we demonstrate that both, additive and multiplicative preconditioners significantly improve the convergence of the standard L-BFGS optimizer, while providing more accurate solutions of the underlying partial differential equations. Moreover, the additive preconditioner is inherently parallel, thus giving rise to a novel approach to model parallelism.
