No CrossRef data available.
Article contents
Approximation of the invariant measure for stable stochastic differential equations by the Euler–Maruyama scheme with decreasing step sizes
Published online by Cambridge University Press: 31 March 2025
Abstract
Let $(X_t)_{t \geqslant 0}$ be the solution of the stochastic differential equation
\[\mathrm{d} X_t = b(X_t) \,\mathrm{d} t+A\,\mathrm{d} Z_t, \quad X_{0}=x,\]
$b\,:\, \mathbb{R}^d \rightarrow \mathbb{R}^d$ is a Lipschitz-continuous function,
$A \in \mathbb{R}^{d \times d}$ is a positive-definite matrix,
$(Z_t)_{t\geqslant 0}$ is a d-dimensional rotationally symmetric
$\alpha$-stable Lévy process with
$\alpha \in (1,2)$ and
$x\in\mathbb{R}^{d}$. We use two Euler–Maruyama schemes with decreasing step sizes
$\Gamma = (\gamma_n)_{n\in \mathbb{N}}$ to approximate the invariant measure of
$(X_t)_{t \geqslant 0}$: one uses independent and identically distributed
$\alpha$-stable random variables as innovations, and the other employs independent and identically distributed Pareto random variables. We study the convergence rates of these two approximation schemes in the Wasserstein-1 distance. For the first scheme, under the assumption that the function b is Lipschitz and satisfies a certain dissipation condition, we demonstrate a convergence rate of
$\gamma^{\frac{1}{\alpha}}_n$. This convergence rate can be improved to
$\gamma^{1+\frac {1}{\alpha}-\frac{1}{\kappa}}_n$ for any
$\kappa \in [1,\alpha)$, provided b has the additional regularity of bounded second-order directional derivatives. For the second scheme, where the function b is assumed to be twice continuously differentiable, we establish a convergence rate of
$\gamma^{\frac{2-\alpha}{\alpha}}_n$; moreover, we show that this rate is optimal for the one-dimensional stable Ornstein–Uhlenbeck process. Our theorems indicate that the recent significant result of [34] concerning the unadjusted Langevin algorithm with additive innovations can be extended to stochastic differential equations driven by an
$\alpha$-stable Lévy process and that the corresponding convergence rate exhibits similar behaviour. Compared with the result in [6], our assumptions have relaxed the second-order differentiability condition, requiring only a Lipschitz condition for the first scheme, which broadens the applicability of our approach.
- Type
- Original Article
- Information
- Copyright
- © The Author(s), 2025. Published by Cambridge University Press on behalf of Applied Probability Trust
References





