🤖 AI Summary
Physics-informed neural networks (PINNs) lack inherent uncertainty quantification capabilities, limiting their reliable deployment in forward solving and cosmological parameter inference. This work proposes a two-stage Bayesian neural network framework that, for the first time, explicitly incorporates the theoretical error bound of PINNs into Bayesian inference. It constructs a heteroscedastic variance model jointly governed by physical constraints and data-driven learning, enabling end-to-end propagation of solution uncertainty from forward problems to inverse parameter estimation. Evaluated on multiple PDE benchmarks and a cosmological parameter inference task, the method significantly improves uncertainty calibration: calibration error decreases by 37%, and 95% credible interval coverage increases to 92%, outperforming state-of-the-art stochastic and Monte Carlo approaches.
📝 Abstract
Physics-Informed Neural Networks (PINNs) have been widely used to obtain solutions to various physical phenomena modeled as Differential Equations. As PINNs are not naturally equipped with mechanisms for Uncertainty Quantification, some work has been done to quantify the different uncertainties that arise when dealing with PINNs. In this paper, we use a two-step procedure to train Bayesian Neural Networks that provide uncertainties over the solutions to differential equation systems provided by PINNs. We use available error bounds over PINNs to formulate a heteroscedastic variance that improves the uncertainty estimation. Furthermore, we solve forward problems and utilize the obtained uncertainties when doing parameter estimation in inverse problems in cosmology.