Viscosity Solutions to Path-Dependent HJB Equation and Applications

Abstract: In this article, the notion of viscosity solution is introduced for the path-dependent Hamilton-Jacobi-Bellman (PHJB) equations associated with the optimal control problems for path-dependent stochastic differential equations. We identify the value functional of the optimal control problems as unique viscosity solution to the associated PHJB equations. Applications to backward stochastic Hamilton-Jacobi-Bellman equations are also given.