Multi-Fidelity Physics-Informed Neural Networks with Bayesian Uncertainty Quantification and Adaptive Residual Learning for Efficient Solution of Parametric Partial Differential Equations
Olaf Yunus Laitinen Imanov
TL;DR
MF-BPINN addresses the computational bottleneck of parametric PDE solving by integrating multi-fidelity learning with physics-informed constraints and Bayesian uncertainty quantification. The framework learns a four-network hierarchy including a low-fidelity predictor, linear and nonlinear correction modules, and a learnable gating mechanism to adapt fidelity contributions across $(x,t,bmu)$. A structured residual formulation separates linear and nonlinear discrepancies, while HMC-based posterior sampling yields calibrated predictive intervals and uncertainty decomposition. Experimental results on Burgers, heat conduction, and Navier–Stokes demonstrate substantial speedups (~7x) and a sixfold improvement in HF sample efficiency, with well-calibrated 95% intervals and robust generalization to new parameter configurations. These findings suggest MF-BPINN provides a practical, uncertainty-aware surrogate framework for efficient parametric PDE solving in engineering contexts.
Abstract
Physics-informed neural networks (PINNs) have emerged as a powerful paradigm for solving partial differential equations (PDEs) by embedding physical laws directly into neural network training. However, solving high-fidelity PDEs remains computationally prohibitive, particularly for parametric systems requiring multiple evaluations across varying parameter configurations. This paper presents MF-BPINN, a novel multi-fidelity framework that synergistically combines physics-informed neural networks with Bayesian uncertainty quantification and adaptive residual learning. Our approach leverages abundant low-fidelity simulations alongside sparse high-fidelity data through a hierarchical neural architecture that learns nonlinear correlations across fidelity levels. We introduce an adaptive residual network with learnable gating mechanisms that dynamically balances linear and nonlinear fidelity discrepancies. Furthermore, we develop a rigorous Bayesian framework employing Hamiltonian Monte Carlo.
