Approximations of spectra of Schrödinger operators with complex potentials on ℝd

Bögli, Sabine; Siegl, Petr und Tretter, Christiane (2017): Approximations of spectra of Schrödinger operators with complex potentials on ℝd. In: Communications in Partial Differential Equations, Bd. 42, Nr. 7: S. 1001-1041

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.

• Dokumententyp: Zeitschriftenartikel
• Fakultät: Mathematik, Informatik und Statistik > Mathematik
• Themengebiete: 500 Naturwissenschaften und Mathematik > 510 Mathematik
• ISSN: 0360-5302
• Sprache: Englisch