General finite-dimensional risk-sensitive problems and small noise limits

For a risk-sensitive, partially observed stochastic control problem, the modified Zakai equation includes an extra term related to the exponential running cost. The finite-dimensional solutions of this modified Zakai equation are obtained. These are analogs of the Kalman and Benes filters. The small noise limits of the finite-dimensional risk-sensitive problems are then obtained. These lead to differential games with deterministic disturbances.