Infinite dimensional time-varying systems with nonlinear output feedback
Infinite-dimensional systems are deeply studied under the extra assumption that the system is linear and time-invariant. Here, the authors develop an existence and robust-stability theory for time-varying infinite-dimensional systems. In the class of systems under investigation, unboundedness in the control and observation operators are allowed. After defining the class of time-varying systems, and the allowed class of (nonlinear) output feedback, the authors give several necessary conditions for the system to stay stable under this class of output feedback. The theory could, for instance, be applied to investigate the stability of a (linearized) partial differential equation. Some of the results presented are new even for finite-dimensional systems.
scientific article; zbMATH DE number 798840