FBSJNN: A Theoretically Interpretable and Efficiently Deep Learning method for Solving Partial Integro-Differential Equations
Zaijun Ye, Wansheng Wang
TL;DR
This work develops Forward-Backward Stochastic Jump Neural Networks (FBSJNN) to solve partial integro-differential equations by transforming PIDEs into FBSDEJs via a nonlinear Feynman-Kac representation and discretizing with Euler-Maruyama. A single neural network approximates the backward component and, through Taylor expansion, the non-local jump integral, enabling efficient training with automatic differentiation. The authors prove consistency: the discretization error scales with $\Delta t$ and the neural network approximation error $\epsilon^{\mathcal{Y}}$, and show that as the network width grows (universal approximation), the method converges to the true FBSDEJ solution. Numerical experiments across 1D and high-dimensional PIDEs and jump-dominated models demonstrate rapid convergence and sub-1e-2 level relative errors, including a high-dimensional test with $d=100$ and a multi-layer financial model. Overall, FBSJNN offers a theoretically grounded, parameter-efficient, scalable framework for high-dimensional stochastic PIDEs with jumps, supported by rigorous consistency results and strong empirical performance.
Abstract
We propose a novel framework for solving a class of Partial Integro-Differential Equations (PIDEs) and Forward-Backward Stochastic Differential Equations with Jumps (FBSDEJs) through a deep learning-based approach. This method, termed the Forward-Backward Stochastic Jump Neural Network (FBSJNN), is both theoretically interpretable and numerically effective. Theoretical analysis establishes the convergence of the numerical scheme and provides error estimates grounded in the universal approximation properties of neural networks. In comparison to existing methods, the key innovation of the FBSJNN framework is that it uses a single neural network to approximate both the solution of the PIDEs and the non-local integral, leveraging Taylor expansion for the latter. This enables the method to reduce the total number of parameters in FBSJNN, which enhances optimization efficiency. Numerical experiments indicate that the FBSJNN scheme can obtain numerical solutions with a relative error on the scale of $10^{-3}$.
