Regularity and propagation of chaos for conditional McKean-Vlasov equations

We study the rate of propagation of chaos for a McKean–Vlasov equation with conditional expectation terms in the drift. We use a (regularized) Nadaraya–Watson estimator at a particle level to approximate the conditional expectations; we then combine relative entropy methods in the spirit of Jabin and Wang (2018) with information theoretic inequalities to obtain the result. The nonparametric nature of the problem requires higher regularity for the density of the McKean–Vlasov limit, which we obtain with a bootstrap argument and energy estimates.