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Spectral inclusion and spectral exactness for singular non-selfadjoint Sturm-Liouville problems

B. M. Brown·M. Marletta
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Abstract

We consider the effect of regularization by interval truncation on the spectrum of a singular non-selfadjoint Sturm-Liouville operator. We present results on spectral inclusion and spectral exactness for the cases where the singularity is in Sims Case II or Sims Case III. For Sims Case I we present a test for spectral inexactness, which can be used to detect when the interval truncation process is generating spurious eigenvalues. Numerical results illustrate the effectiveness of this test.

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B. M. Brown, M. Marletta. 2000-06-28. Spectral inclusion and spectral exactness for singular non-selfadjoint Sturm-Liouville problems. https://doi.org/10.1098/rspa.2000.0659

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