Numerical range for certain classes of operators
Author:
Richard Bouldin
Journal:
Proc. Amer. Math. Soc. 34 (1972), 203-206
MSC:
Primary 47A10
DOI:
https://doi.org/10.1090/S0002-9939-1972-0293424-X
MathSciNet review:
0293424
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Abstract | References | Similar Articles | Additional Information
Abstract: We prove a basic result which relates the structure of the spectrum to the interior of the numerical range. Using this result we derive corollaries concerning compact operators, quasinilpotents, and finite dimensional operators. In particular, we characterize finite dimensional convexoid operators.
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Additional Information
DOI:
https://doi.org/10.1090/S0002-9939-1972-0293424-X
Keywords:
Hilbert space operator,
numerical range,
eigenvalues,
convex set,
extreme points,
closed range
Article copyright:
© Copyright 1972
American Mathematical Society