Order-one explicit approximations of random periodic solutions of semi-linear SDEs with multiplicative noise
Yujia Guo, Xiaojie Wang, Yue Wu
TL;DR
The study addresses computing random periodic solutions for semi-linear SDEs with multiplicative noise under non-globally Lipschitz drift/diffusion. It introduces a projection-enhanced Milstein scheme (PMM) that remains explicit and proves pull-back convergence of the discretized process to the true RPS, achieving order-one mean-square accuracy on infinite time horizons without requiring high-moment bounds a priori. The authors further prove existence and uniqueness of the PMM's random periodic solution and establish $O(h)$ convergence of the numerical RPS to the exact RPS under a mild timestep constraint. Numerical experiments corroborate the theory, showing PMM outperforms PEM with clear near-linear convergence in practice, validating the method's efficiency for long-time simulations of RPS.
Abstract
This paper is devoted to order-one explicit approximations of random periodic solutions to multiplicative noise driven stochastic differential equations (SDEs) with non-globally Lipschitz coefficients. The existence of the random periodic solution is demonstrated as the limit of the pull-back of the discretized SDE. A novel approach is introduced to analyze mean-square error bounds of the proposed scheme that does not depend on a prior high-order moment bounds of the numerical approximations. Under mild assumptions, the proposed scheme is proved to achieve an expected order-one mean square convergence in the infinite time horizon. Numerical examples are finally provided to verify the theoretical results.
