subnormal operator


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subnormal operator

[′səb‚nȯr·məl ′äp·ə‚rād·ər]
(mathematics)
An operator A on a Hilbert spaceHis said to be subnormal if there exists a normal operator B on a Hilbert spaceKsuch thatHis a subspace ofK, the subspaceHis invariant under the operator B, and the restriction of B toHcoincides with A.
References in periodicals archive ?
The analytic model represents a subnormal operator as the multiplication by the independent variable of a space of vector-valued functions that are analytic on the resolvent set of its normal extension, says Xia.
Feldman, "Essentially subnormal operators," Proceedings of the American Mathematical Society, vol.
We refer the reader to [6, 16-19] for the foundations of the theory of bounded and unbounded subnormal operators, respectively.