Stochastic viscosity solutions of reflected stochastic partial differential equations with non-Lipschitz coefficients

Abstract

This paper, is an attempt to extend the notion of stochastic viscosity solution to reflected semi-linear stochastic partial differential equations (RSPDEs, in short) with non-Lipschitz condition on the coefficients. Our method is fully probabilistic and use the recently developed theory on reflected backward doubly stochastic differential equations (RBDSDEs, in short). Among other, we prove the existence of the stochastic viscosity solution, and further extend the nonlinear Feynman-Kac formula to reflected SPDEs, like one appear in [2]. Indeed, in their recent work, Aman and Mrhardy [2] established a stochastic viscosity solution for semi-linear reflected SPDEs with nonlinear Neumann boundary condition by using its connection with RBDSDEs. However, even Aman and Mrhardy consider a general class of reflected SPDEs, all their coefficients are at least Lipschitz. Therefore, our current work can be thought of as a new generalization of a now well-know Feymann-Kac formula to SPDEs with large class of coefficients, which does not seem to exist in the literature. In other words, our work extends (in non boundary case) Aman and Mrhardy's paper.