Abstract
We study spectral approximations of Schrodinger operators T=-+Q with complex potentials on =(d), or exterior domains < subset of>(d), by domain truncation. Our weak assumptions cover wide classes of potentials Q for which T has discrete spectrum, of approximating domains (n), and of boundary conditions on (n) such as mixed Dirichlet/Robin type. In particular, Re Q need not be bounded from below and Q may be singular. We prove generalized norm resolvent convergence and spectral exactness, i.e. approximation of all eigenvalues of T by those of the truncated operators T(n)without spectral pollution. Moreover, we estimate the eigenvalue convergence rate and prove convergence of pseudospectra. Numerical computations for several examples, such as complex harmonic and cubic oscillators for d=1,2,3, illustrate our results.
Item Type: | Journal article |
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Faculties: | Mathematics, Computer Science and Statistics > Mathematics |
Subjects: | 500 Science > 510 Mathematics |
ISSN: | 0360-5302 |
Language: | English |
Item ID: | 55641 |
Date Deposited: | 14. Jun 2018, 09:59 |
Last Modified: | 13. Aug 2024, 12:42 |