Spectra of 2 × 2 Upper-Triangular Operator Matrices

Abstract

In [Perturbation of Spectrums of 2 × 2 Operator Matrices, Proceedings of the American Mathematical Society, Vol. 121, 1994], the authors asked whether there was an operator  such that  for a given pair (A,B) of operators, where the operator  was defined by . In this note, a partial answer for the question is given.

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H. Zhang, "Spectra of 2 × 2 Upper-Triangular Operator Matrices," Applied Mathematics, Vol. 4 No. 11A, 2013, pp. 22-25. doi: 10.4236/am.2013.411A1004.

Conflicts of Interest

The authors declare no conflicts of interest.

References

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