A duality method for mean-field limits with singular interactions
Didier Bresch, Mitia Duerinckx, Pierre-Emmanuel Jabin
TL;DR
This work develops a duality-based framework to derive mean-field limits for both first- and second-order particle systems with singular interactions, allowing arbitrary square-integrable kernels at possibly vanishing temperature. By reformulating the problem via a backward dual Liouville equation, the authors study linear dual correlations in a weighted Hilbert space $L^2_f$, derive a BBGKY-type limit hierarchy for the dual correlations, and prove propagation of chaos toward the Vlasov equation $\partial_t f + v\cdot\nabla_x f + (K\!* f)\cdot\nabla_v f=\alpha\Delta_v f$. They further provide explicit hierarchical equations, robust a priori estimates, a truncated rescaled hierarchy with vanishing remainders, and a quantitative rate of convergence $\|F_{N,k}(t)-f(t)^{\otimes k}\|_{C_c^*} \lesssim (N^{-1/2}+N^{s(1/p-1/2)})^{e^{-Ct}}$, highlighting the role of regularity and diffusion. The method yields convergence to the 2d Euler/Navier–Stokes equations in the first-order setting and delivers convergence rates beyond previous approaches, with potential applicability to a broad class of singular kernels.
Abstract
We introduce a new approach to derive mean-field limits for first- and second-order particle systems with singular interactions. It is based on a duality approach combined with the analysis of linearized dual correlations, and it allows to cover for the first time arbitrary square-integrable interaction forces at possibly vanishing temperature. In case of first-order systems, it allows to recover in particular the mean-field limit to the 2d Euler and Navier-Stokes equations. The approach also provides convergence rates.
