Properties of hitting times for -martingales and their applications

In this article, we consider the properties of hitting times for G -martingales and the stopped processes. We prove that the stopped processes for G -martingales are still G -martingales and that the hitting times for a class of G -martingales including one-dimensional G -Brownian motion are quasi-continuous. As an application, we improve the G -martingale representation theorems of [7].