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Quarterly of Applied Mathematics

Quarterly of Applied Mathematics

Online ISSN 1552-4485; Print ISSN 0033-569X

   
 
 

 

Structure for nonnegative square roots of unbounded nonnegative selfadjoint operators


Authors: Peng-Fei Yao and De-Xing Feng
Journal: Quart. Appl. Math. 54 (1996), 457-473
MSC: Primary 47B25; Secondary 34L10, 47A60, 47E05
DOI: https://doi.org/10.1090/qam/1402405
MathSciNet review: MR1402405
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Abstract: It is well known that, for an unbounded nonnegative selfadjoint operator $A$ on a Hilbert space, there is a unique nonnegative square root ${A^{1/2}}$, which is frequently associated with the structural damping in many practical vibration systems. In this paper we develop a general theory for the structure of ${A^{1/2}}$, which includes the expression of ${A^{1/2}}$ and a program to find the domain of ${A^{1/2}}$ explicitly from the domain of $A$. The relationship between ${A^{1/2}}$ and related differential operators is determined for the selfadjoint differential operator $A$. Finally, the theoretical results given in this paper are applied to fourth-order “beam” operators and $n$-dimensional “wave” operators with sufficient complexity for applications to elastic vibration systems.


References [Enhancements On Off] (What's this?)

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Article copyright: © Copyright 1996 American Mathematical Society