Self-interacting approximation to McKean-Vlasov long-time limit: a Markov chain Monte Carlo method
Kai Du, Zhenjie Ren, Florin Suciu, Songbo Wang
TL;DR
The paper introduces a self-interacting diffusion as a scalable proxy for the long-time behavior of non-degenerate McKean–Vlasov dynamics, replacing the mean-field interaction with an exponentially weighted occupation measure. It proves exponential ergodicity of the self-interacting process via a reflection-coupling argument and provides quantitative bounds showing that, in the gradient setting, the SI stationary distribution closely approximates the MKV invariant measure as the interaction rate $\lambda$ decreases. A broad class of dynamics is identified for which these results hold, and a concrete Curie–Weiss/ferromagnetic example illustrates the methodology. The numerical application to training two-layer neural networks demonstrates a practical, single-particle mean-field approach with an annealing scheme that outperforms fixed-parameter runs, highlighting the method's potential for scalable learning in high-dimensional systems.
Abstract
For a certain class of McKean-Vlasov processes, we introduce proxy processes that substitute the mean-field interaction with self-interaction, employing a weighted occupation measure. Our study encompasses two key achievements. First, we demonstrate the ergodicity of the self-interacting dynamics, under broad conditions, by applying the reflection coupling method. Second, in scenarios where the drifts are negative intrinsic gradients of convex mean-field potential functionals, we use entropy and functional inequalities to demonstrate that the stationary measures of the self-interacting processes approximate the invariant measures of the corresponding McKean-Vlasov processes. As an application, we show how to learn the optimal weights of a two-layer neural network by training a single neuron.
