Stabilization of second order evolution equations with unbounded feedback with delay

Stabilization of second order evolution equations with unbounded feedback with delay Serge Nicaise?, Julie Valein† December 1, 2008 Abstract We consider abstract second order evolution equations with unbounded feedback with delay. Existence results are obtained under some realistic assumptions. Sufficient and explicit conditions are derived that guarantee the exponential or polynomial stability. Some new examples that enter into our abstract framework are presented. Keywords second order evolution equations, wave equations, delay, stabi- lization functional. 1 Introduction Time-delay often appears in many biological, electrical engineering systems and mechanical applications [11, 21, 1], and in many cases, in particular for dis- tributed parameter systems, even arbitrarily small delays in the feedback may destabilize the system, see e.g. [8, 9, 10, 12, 15, 16, 17, 20, 23]. The stability issue of systems with delay is, therefore, of theoretical and practical importance. We further remark that some techniques developed recently [16, 17] in order to obtain some existence results and decay rates have some similarities. We therefore propose to consider an abstract setting as large as possible in order to contain a quite large class of problems with time delay feedbacks. In a second step we prove existence and stability results in this setting under realistic assumptions. Finally in order to show the usefulness of our approach, we give some examples where our abstract framework can be applied.

• valenciennes


• delay increases


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• evolution equations


• ?université de valenciennes et du hainaut cambrésis


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• self-adjoint positive operator