Tamed Euler-Maruyama method for SDEs with non-globally Lipschitz drift and multiplicative noise
Xiang Li, Yingjun Mo, Haoran Yang
TL;DR
The paper addresses long-time numerical approximation of SDEs with non-globally Lipschitz drift and multiplicative noise using a Newton-based tamed Euler–Maruyama scheme with variable step sizes. By establishing moment bounds, one-step error estimates, and gradient bounds for the SDE semigroups, and applying a domino decomposition together with Malliavin-type techniques, the authors prove uniform-in-time convergence in $\mathbb{W}_1$ and $d_{TV}$ at a rate $C\eta_n^{\alpha}$ for any $\alpha\in(0,\tfrac12)$. The results rely on partial dissipativity (ergodicity) assumptions and careful control of the taming, enabling explicit rates and applicability to additive noise cases as well. The work provides a practically implementable long-time scheme with provable convergence guarantees for challenging SDEs with super-linear drift, supported by detailed moment, one-step, and gradient analyses. Overall, the paper contributes a rigorous framework for stable long-time simulation of non-globally Lipschitz SDEs under multiplicative noise, with explicit rate information dependent on the step-size sequence $\{\eta_n\}$.
Abstract
Consider the following stochastic differential equation driven by multiplicative noise on $\mathbb{R}^d$ with a superlinearly growing drift coefficient, \begin{align*} \mathrm{d} X_t = b (X_t) \, \mathrm{d} t + σ(X_t) \, \mathrm{d} B_t. \end{align*} It is known that the corresponding explicit Euler schemes may not converge. In this article, we analyze an explicit and easily implementable numerical method for approximating such a stochastic differential equation, i.e. its tamed Euler-Maruyama approximation. Under partial dissipation conditions ensuring the ergodicity, we obtain the uniform-in-time convergence rates of the tamed Euler-Maruyama process under $L^{1}$-Wasserstein distance and total variation distance.
