Non-Hermitian oscillators with symmetry
arXiv:1409.2672 · doi:10.1016/j.aop.2014.11.018
Abstract
We analyse some PT-symmetric oscillators with symmetry that depend on a potential parameter . We calculate the eigenvalues and eigenfunctions for each irreducible representation and for a range of values of . Pairs of eigenvalues coalesce at exceptional points ; their magnitude roughly decreasing with the magnitude of the eigenvalues. It is difficult to estimate whether there is a phase transition at a nonzero value of as conjectured in earlier papers. Group theory and perturbation theory enable one to predict whether a given space-time symmetry leads to real eigenvalues for sufficiently small nonzero values of .