$L^p$-sup Convergence of the Euler-Maruyama Scheme for SDEs with Distributional Besov Drift
Matteo Cagnotti
TL;DR
This work tackles numerical approximation of one-dimensional SDEs with drift in a distributional Besov space, driven by Brownian motion. By combining a Zvonkin-type transformation with mollification and the Yamada–Watanabe approximation, it reduces the problem to solving a regularized SDE and analyzes the error via a stochastic Grönwall framework, yielding $L^p$-sup convergence for $p\ge2$ with explicit rates and an $L^1$-sup convergence rate. The results hold under $b \in C_T^{1/2}\mathcal{C}^{(-\beta)+}$ with $\beta\in(0,1/2)$ and provide precise rate formulas involving $r(\beta,\varepsilon)$, improving understanding of numerical schemes for SDEs with highly singular drifts. The methods integrate virtual solutions, mollified Euler schemes, and local-time techniques, offering a robust approach to strong convergence in Besov-drift settings with potential implications for rough forcing models and singular interactions.
Abstract
In this paper we extend existing results on the numerical approximation of one-dimensional SDEs with drift in a negative order Besov space and driven by Brownian motion. Using the Yamada-Watanabe approximation technique, we prove rates in $L^p$, for all $p\geq 2$, applying a Gronwall-type lemma previously used in the literature for SDEs with Hölder continuous coefficients. Additionally, we obtain an explicit convergence rate in the $L^1$-$\sup$ norm.
