Smoluchowski-Kramers approximation for singular stochastic wave equations in two dimensions

Abstract

We study a family of nonlinear damped wave equations indexed by a parameter $\hat{I}\mu >0$ and forced by a space-time white noise on the two dimensional torus, with polynomial and sine nonlinearities. We show that as $\hat{I}\mu \to 0$, the solutions to these equations converge to the solution of the corresponding two dimensional stochastic quantization equation. In the sine nonlinearity case, the convergence is proven over arbitrary large times, while in the polynomial case, we prove that this approximation result holds over arbitrary large times when the parameter $\hat{I}\mu$ goes to zero even with a lack of suitable global well-posedness theory for the corresponding wave equations.

Revised version