THE NORM OPTIMAL CONTROL PROBLEM FOR STOCHASTIC LINEAR CONTROL SYSTEMS

In this paper we are concerned with two norm optimal control problems for different stochastic linear control systems. One is for approximately controllable systems with the natural filtra- tion, while another is for exactly controllable systems with a general filtration. For each aforementioned norm optimal control problem, we construct the unique norm optimal control, through building up some suitable quadratic functional and making use of a variational characterization on its minimizer.