Dicke, AlexanderSeelmann, Albrecht2023-08-112023-08-112022-07-28http://hdl.handle.net/2003/42057http://dx.doi.org/10.17877/DE290R-23890In this note, an alternative approach to establish observability for semigroups based on their smoothing properties is presented. The results discussed here reproduce some of those recently obtained in [arXiv:2112.01788], but the current proof allows to get rid of several technical assumptions by following the standard complex analytic approach established by Kovrijkine combined with an idea from [arXiv:2201.02370].enUnique continuation principleObservabilityGelfand–Shilov smoothing effects510Text