Weak well-posedness of energy solutions to singular SDEs with supercritical distributional drift

Lukas Gräfner, Nicolas Perkowski

Published 2024-07-12Version 1

We study stochastic differential equations with additive noise and distributional drift on $\mathbb{T}^d$ or $\mathbb{R}^d$ and $d \geqslant 2$. We work in a scaling-supercritical regime using energy solutions and recent ideas for generators of singular stochastic partial differential equations. We mainly focus on divergence-free drift, but allow for scaling-critical non-divergence free perturbations. In the time-dependent divergence-free case we roughly speaking prove weak well-posedness of energy solutions with initial law $\mu \ll \text{Leb}$ for drift $b \in L^p_T B^{-\gamma}_{p, 1}$ with $p \in (2, \infty]$ and $p \geqslant \frac{2}{1 -\gamma}$. For time-independent $b$ we show weak well-posedness of energy solutions with initial law $\mu \ll \text{Leb}$ under certain structural assumptions on $b$ which allow local singularities such that $b \notin B^{-1}_{2 d/(d-2), 2}$, meaning that for any $p > 2$ in sufficiently high dimension there exists $b \notin B^{-1}_{p, 2}$ such that weak well-posedness holds for energy solutions with drift $b$.