• Kubrusly, Carlos S. (Catholic University of Rio de Janeiro) ;
  • Levan, Nhan (Department of Electrical Engineering University of California in Los Angeles)
  • Received : 2010.06.29
  • Published : 2012.01.31


The concept of Hilbert space dissipative norm was introduced in [8] to obtain necessary and sufficient conditions for exponential stability of contraction semigroups. In the present paper we show that the same concept can also be used to derive further properties of contraction semigroups, as well as to characterize strongly stable semigroups that are not exponentially stable.


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