NONLINEAR DELAY SYSTEMS CONTROLLABILITY

This research resolves some controllability questions of general nonlinear delay systems in function space in which earlier solutions of the optimal problem have been shown to exist. By using a powerful open mapping theorem and Gateaux differentiability, we avoid the difficult requirement of Fréchet differentiability of an operator F: Wp(1) × Lp → Wp(1) which is associated with the nonlinear system. Properties of the linearized system help ensure the nonlinear system's controllability. © 1991.