Essential numerical range in

Authors:
D. A. Legg and D. W. Townsend

Journal:
Proc. Amer. Math. Soc. **81** (1981), 541-545

MSC:
Primary 47A12

MathSciNet review:
601725

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Abstract | References | Similar Articles | Additional Information

Abstract: In recent years, the numerical range lifting problem has been solved for operators on , , and on certain Orlicz spaces . Specifically, given an operator , there exists a compact perturbation such that the numerical range of equals the essential numerical range of . This result has also been established for essentially Hermitian operators on . In the present paper, the authors establish this result for all operators on .

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DOI:
https://doi.org/10.1090/S0002-9939-1981-0601725-3

Keywords:
Essential numerical range,
Calkin algebra,
lifting problems,
-ideal

Article copyright:
© Copyright 1981
American Mathematical Society