A uniform particle approximation to the Navier-Stokes-alpha models in three dimensions with advection noise

Abstract

In this work, we investigate a system of interacting particles governed by a set of stochastic differential equations. Our main goal is to rigorously demonstrate that the empirical measure associated with the particle system converges uniformly, both in time and space, to the solution of the three dimensional Navier Stokes alpha model with advection noise. This convergence establishes a probabilistic framework for deriving macroscopic stochastic fluid equations from underlying microscopic dynamics. The analysis leverages semigroup techniques to address the nonlinear structure of the limiting equations, and we provide a detailed treatment of the well posedness of the limiting stochastic partial differential equation. This ensures that the particle approximation remains stable and controlled over time. Although similar convergence results have been obtained in two dimensional settings, our study presents the first proof of strong uniform convergence in three dimensions for a stochastic fluid model derived from an interacting particle system. Importantly, our results also yield new insights in the deterministic regime, namely, in the absence of advection noise, where this type of convergence had not been previously established.