Turnpike property for hierarchical optimal control problems: from particle systems to hydrodynamic equations
Michael Herty, Yizhou Zhou
TL;DR
This work analyzes exponential turnpike properties across a hierarchy of controlled dynamics: an $N$-particle system, its mean-field limit, and macroscopic hydrodynamic closures. By constructing feedback controls and proving cheap-control properties at each level, it derives Gronwall-based bounds that yield exponential convergence toward steady states as the horizon grows. The main contributions are the uniform-in-$N$ turnpike estimates for the particle system, their rigorous mean-field passage, and the analogous results for two hydrodynamic closures (Type I and Type II Euler equations) with both pressure-less and full-energy formulations. The results provide a unified framework linking microscopic, kinetic, and macroscopic optimal-control descriptions, with potential implications for scalable stabilization and control of multi-scale collective dynamics.
Abstract
This work is concerned with a hierarchical framework of optimal control problems connecting interacting particle systems, the mean field limit equations, and associated hydrodynamic models. By assuming the existence of solutions, we establish the exponential turnpike property for each level of the hierarchy, showing that optimal trajectories remain close to the associated steady states over long time horizons. The results demonstrate that the exponential turnpike behavior persists consistently across scales, providing a unified connection between microscopic, kinetic, and macroscopic optimal control frameworks.
