On the admissibility of observation for perturbed l(0)-semigroups on Banach spaces

摘要

This paper concerns linear infinite-dimensional systems with unbounded observation operators. We study the invariance of admissibility for observation operators under some unbounded perturbations of the generator. We give also some relations between the A-extensions of such observation operators with respect to the original generator and the perturbed generator. Our results are applied to functional differential linear systems. (c) 2005 Elsevier B.V. All rights reserved.