Functional Tensor Decompositions for Physics-Informed Neural Networks
Sai Karthikeya Vemuri, Tim Büchner, Julia Niebling, Joachim Denzler
TL;DR
This work tackles the challenge of solving high-dimensional PDEs with Physics-Informed Neural Networks (PINNs) by introducing functional tensor decompositions to separate variables. By representing the multivariate solution as an outer product of univariate neural networks, the authors develop CP-PINN, TT-PINN, and Tucker-PINN architectures that learn per-dimension components and combine them according to canonical, TT, or Tucker decompositions. The method achieves significant accuracy gains and reduced collocation requirements on benchmarks such as the Klein-Gordon, Helmholtz, and 5D Poisson equations, demonstrating up to an order-of-magnitude improvement in efficiency over state-of-the-art PINNs. This tensor-decomposition-enhanced PINN framework mitigates the curse of dimensionality and extends the applicability of PINNs to higher-dimensional PDE problems with scalable performance.
Abstract
Physics-Informed Neural Networks (PINNs) have shown continuous and increasing promise in approximating partial differential equations (PDEs), although they remain constrained by the curse of dimensionality. In this paper, we propose a generalized PINN version of the classical variable separable method. To do this, we first show that, using the universal approximation theorem, a multivariate function can be approximated by the outer product of neural networks, whose inputs are separated variables. We leverage tensor decomposition forms to separate the variables in a PINN setting. By employing Canonic Polyadic (CP), Tensor-Train (TT), and Tucker decomposition forms within the PINN framework, we create robust architectures for learning multivariate functions from separate neural networks connected by outer products. Our methodology significantly enhances the performance of PINNs, as evidenced by improved results on complex high-dimensional PDEs, including the 3d Helmholtz and 5d Poisson equations, among others. This research underscores the potential of tensor decomposition-based variably separated PINNs to surpass the state-of-the-art, offering a compelling solution to the dimensionality challenge in PDE approximation.
