English

Propagation of chaos in Fisher information

Probability 2025-11-26 v1

Abstract

We present a new method for proving sharp local propagation of chaos in Fisher Information for particles with smooth interaction and drift. We rely on a new Lemma computing the Fisher Information of two diffusion processes with smooth drifts and fine estimates on the hessian of the law of the solution of the McKean-Vlasov equation. It allows us to obtain a new propagation of chaos in Fisher information, generalizing Lacker's seminal work by using the BBGKY hierarchy to obtain a system of differential inequalities satisfied by both the relative entropy and the Fisher Information of k particles. We also show with a simple Gaussian example that our decay rate is optimal.

Keywords

Cite

@article{arxiv.2511.20078,
  title  = {Propagation of chaos in Fisher information},
  author = {Jules Grass and Christophe Poquet and Arnaud Guillin},
  journal= {arXiv preprint arXiv:2511.20078},
  year   = {2025}
}