Study of an optimal control problem related to the Solow control model

We study the Solow model of optimal economic growth. The statement of the optimal control problem under consideration contains mixed constraints on the control. A special change of the control is used to reduce the problem to the study of a new controlled object with a usual geometric constraint. The reachable set of the original control system is found, an existence theorem for the optimal control is proved, and sufficient conditions for absence of singular regimes are obtained.