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Upper and lower Fredholm spectra. I


Authors: John J. Buoni, Robin Harte and Tony Wickstead
Journal: Proc. Amer. Math. Soc. 66 (1977), 309-314
MSC: Primary 47A10
DOI: https://doi.org/10.1090/S0002-9939-1977-0454676-0
MathSciNet review: 0454676
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Abstract: Joint upper and lower Fredholm spectra are defined for n-tuples of bounded linear operators, and the upper Fredholm spectrum is represented both as the simultaneous eigenvalues and as the simultaneous approximate eigenvalues of an n-tuple of operators obtained by a Berberian-Quigley construction.


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Additional Information

DOI: https://doi.org/10.1090/S0002-9939-1977-0454676-0
Keywords: Fredholm operators, Calkin spaces, Berberian-Quigley constructions, sequences with totally bounded range, measures of noncompactness, upper and lower Fredholm spectrum, essential spectra, spectral mapping theorems
Article copyright: © Copyright 1977 American Mathematical Society

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