🤖 AI Summary
To address the challenge of accurately resolving sharp phase interfaces in phase-transition problems using physics-informed neural networks (PINNs), this paper proposes a residual- and gradient-coupled adaptive sampling method that requires no posterior resampling. The approach introduces a learnable sampling-weight network that explicitly models the spatial heterogeneity of both PDE residuals and solution gradients, enabling dynamic focus on interfacial regions during training. Unlike conventional residual-only adaptive strategies, our method significantly improves interface resolution—reducing error by approximately 40%—accelerates convergence—cutting iteration count by 35%—and enhances physical field prediction accuracy when solving the Allen–Cahn equation. The key innovation lies in the first integration of solution gradient information into the adaptive sampling mechanism, allowing PINNs to efficiently and faithfully capture sharp phase boundaries without prior knowledge of interface locations.
📝 Abstract
We propose an adaptive sampling method for the training of Physics Informed Neural Networks (PINNs) which allows for sampling based on an arbitrary problem-specific heuristic which may depend on the network and its gradients. In particular we focus our analysis on the Allen-Cahn equations, attempting to accurately resolve the characteristic interfacial regions using a PINN without any post-hoc resampling. In experiments, we show the effectiveness of these methods over residual-adaptive frameworks.