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Essential spectra of quasisimilar-quasihyponormal operators

Abstract

It is shown that if is an upper-triangular operator matrix acting on the Hilbert space and if denotes the essential spectrum, then the passage from to is accomplished by removing certain open subsets of from the former. Using this result we establish that quasisimilar-quasihyponormal operators have equal spectra and essential spectra.

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Correspondence to An-Hyun Kim.

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Kim, AH., Kim, I.H. Essential spectra of quasisimilar-quasihyponormal operators. J Inequal Appl 2006, 72641 (2006). https://doi.org/10.1155/JIA/2006/72641

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Keywords

  • Hilbert Space
  • Open Subset
  • Operator Matrix
  • Essential Spectrum
  • Equal Spectrum
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