A novel second order scheme with one step for forward backward stochastic differential equations
Qiang Han, Shihao Lan, Quanxin Zhu
TL;DR
The paper tackles numerical solution of decoupled forward-backward stochastic differential equations (FBSDEs) by introducing a novel explicit one-step second-order discretization parameterized by $α ∈ (0,1]$, which recovers Crank–Nicolson when $α=1$. It provides a stability analysis and local truncation error bounds via Itô–Taylor expansions, leading to a global error bound that confirms second-order convergence. Numerical experiments on a scalar BSDE and a FitzHugh–Nagumo–type FBSDE validate the theory, showing near–two order convergence across different $α$ values and demonstrating that the method remains efficient and fully explicit for both $Y$ and $Z$. The work offers a practical, high-order alternative to multistep or implicit schemes and lays groundwork for constructing higher-order one-step methods.
Abstract
In this paper, we present a novel explicit second order scheme with one step for solving the forward backward stochastic differential equations, with the Crank-Nicolson method as a specific instance within our proposed framework. We first present a rigorous stability result, followed by precise error estimates that confirm the proposed novel scheme achieves second-order convergence. The theoretical results for the proposed methods are supported by numerical experiments.
