Saved in:
Bibliographic Details
Main Authors: Ferreira, Rita, Gomes, Diogo, Majrashi, Bashayer
Format: Preprint
Published: 2026
Subjects:
Online Access:https://arxiv.org/abs/2604.00681
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866918423295950848
author Ferreira, Rita
Gomes, Diogo
Majrashi, Bashayer
author_facet Ferreira, Rita
Gomes, Diogo
Majrashi, Bashayer
contents We extend the weak-strong uniqueness principle for mean-field game (MFG) systems to a broad class of second-order stationary and time-dependent problems. Under standard monotonicity, growth, and coercivity assumptions on the Hamiltonian, and relying strictly on the integrability exponents guaranteed by the existing theory for monotone MFG systems, we show that any weak solution must coincide with a given strong solution. Our analysis covers models with spatially dependent scalar diffusion coefficients, using monotonicity arguments and a coefficient-adapted mollification strategy to manage the variable diffusion terms. We extend this strategy to establish weak-strong uniqueness in the corresponding second-order, initial-terminal, time-dependent setting. Finally, to address the critical quadratic growth regime, we derive a new a priori second-order estimate for a stationary MFG system with logarithmic coupling. This estimate provides quantitative bounds on the solution in terms of the data, and yields weak-strong uniqueness in the range where the improved integrability yields $L^2$ control of the density. Since numerical and approximation methods for MFGs naturally yield weak solutions in the monotonicity sense, whereas strong solutions are known to exist in many settings, our results identify any weak limit produced by such methods with the strong solution whenever one exists.
format Preprint
id arxiv_https___arxiv_org_abs_2604_00681
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Weak-Strong Uniqueness for Second-Order Mean-Field Games
Ferreira, Rita
Gomes, Diogo
Majrashi, Bashayer
Analysis of PDEs
Dynamical Systems
We extend the weak-strong uniqueness principle for mean-field game (MFG) systems to a broad class of second-order stationary and time-dependent problems. Under standard monotonicity, growth, and coercivity assumptions on the Hamiltonian, and relying strictly on the integrability exponents guaranteed by the existing theory for monotone MFG systems, we show that any weak solution must coincide with a given strong solution. Our analysis covers models with spatially dependent scalar diffusion coefficients, using monotonicity arguments and a coefficient-adapted mollification strategy to manage the variable diffusion terms. We extend this strategy to establish weak-strong uniqueness in the corresponding second-order, initial-terminal, time-dependent setting. Finally, to address the critical quadratic growth regime, we derive a new a priori second-order estimate for a stationary MFG system with logarithmic coupling. This estimate provides quantitative bounds on the solution in terms of the data, and yields weak-strong uniqueness in the range where the improved integrability yields $L^2$ control of the density. Since numerical and approximation methods for MFGs naturally yield weak solutions in the monotonicity sense, whereas strong solutions are known to exist in many settings, our results identify any weak limit produced by such methods with the strong solution whenever one exists.
title Weak-Strong Uniqueness for Second-Order Mean-Field Games
topic Analysis of PDEs
Dynamical Systems
url https://arxiv.org/abs/2604.00681