The viscous variational wave equation with transport noise
Peter H. C. Pang
TL;DR
This work analyzes the viscous variational wave equation with transport-type noise on the torus and proves pathwise global existence, uniqueness, and temporal continuity of solutions in $L^2(T)$. A two-level Galerkin framework with a nonlinear cutoff yields approximate equations for $(R,S)$, from which martingale solutions are obtained via Skorokhod--Jakubowski with Dudley maps; pathwise uniqueness is then established through renormalization and double commutator estimates, enabling a Gyöngy–Krylov/Yamada–Watanabe upgrade to strong solutions. The analysis blends deterministic variational-wave techniques with stochastic compactness and refined commutator controls for the transport noise, culminating in continuous-in-time $L^2$-paths for the limit. The results provide a rigorous foundation for well-posedness of stochastic viscoelastic-type wave dynamics under transport noise and set the stage for vanishing-viscosity limits and dissipative/conservative behavior studies in higher complexity models.
Abstract
This article considers the variational wave equation with viscosity and transport noise as a system of three coupled nonlinear stochastic partial differential equations. We prove pathwise global existence, uniqueness, and temporal continuity of solutions to this system in $L^2_x$. Martingale solutions are extracted from a two-level Galerkin approximation via the Skorokhod--Jakubowski theorem. We use the apparatus of Dudley maps to streamline this stochastic compactness method, bypassing the usual martingale identification argument. Pathwise uniqueness for the system is established through a renormalisation procedure that involves double commutator estimates and a delicate handling of noise and nonlinear terms. New model-specific commutator estimates are proven.
