Verified numerical computations for eigenvalues of non-commutative harmonic oscillators

K. Nagatou*, M. T. Nakao, M. Wakayama

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

19 Citations (Scopus)


We study the eigenvalue problem of the formally self-adjoint operator Q(αβ) ≡ I(αβ) (-1/2 d2/dx2 + x2/2) + J (x d/dx + 1/2), x ∈ R, where I(αβ) ≡ equation omitted, J ≡ equation omitted ∈ Mat2 (R), and α and β are positive real constants satisfying αβ > 1. This latter condition makes the operator Q(αβ) to be elliptic. The operator Q(αβ) defines a sort of non-trivial couple of the usual harmonic oscillators and was first introduced and studied by Parmeggiani et al. (Parmeggiani, A.; Wakayama, M. Non-Commutative Harmonic Oscillators-I. Forum Mathematicum 2002, 14, 539-604). However, since one has only a limited understanding of its explicit value of eigenvalues, a behavior of eigenfunctions and an information about the multiplicity of each eigenvalue, here we try to make a numerical approach to this system. More precisely, applying a numerical enclosure method for elliptic eigenvalue problems which is based on the verification procedure for nonlinear elliptic equations established by Nagatou (Nagatou, K. A Numerical Method to Verify the Elliptic Eigenvalue Problems Including a Uniqueness Property. Computing 1999, 63, 109-130; Nakao, M.T.; Yamamoto, N.; Nagatou, K. Numerical Verifications for Eigenvalues of Second-Order Elliptic Operators. Japan Journal of Industrial and Applied Mathematics 1999, 16, 307-320) to such coupling type eigenvalue problems in the unbounded domain, we develop a verified numerical computation of the eigenvalue of Q(αβ) and its multiplicity.

Original languageEnglish
Pages (from-to)633-650
Number of pages18
JournalNumerical Functional Analysis and Optimization
Issue number5-6
Publication statusPublished - 2002 Aug
Externally publishedYes


  • Elliptic eigenvalue problems
  • Harmonic oscillators
  • Numerical enclosure

ASJC Scopus subject areas

  • Analysis
  • Signal Processing
  • Computer Science Applications
  • Control and Optimization


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