1 research outputs found
On the eigenvalues of some nonhermitian oscillators
We consider a class of one-dimensional nonhermitian oscillators and discuss
the relationship between the real eigenvalues of PT-symmetric oscillators and
the resonances obtained by different authors. We also show the relationship
between the strong-coupling expansions for the eigenvalues of those
oscillators. Comparison of the results of the complex rotation and the
Riccati-Pad\'{e} methods reveals that the optimal rotation angle converts the
oscillator into either a PT-symmetric or an Hermitian one. In addition to the
real positive eigenvalues the PT-symmetric oscillators exhibit real positive
resonances under different boundary conditions. They can be calculated by means
of the straightforward diagonalization method. The Riccati-Pad\'e method yields
not only the resonances of the nonhermitian oscillators but also the
eigenvalues of the PT-symmetric ones