On half-line spectra for a class of non-self-adjoint Hill operators

2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/57483In 1980, Gasymov showed that non-self-adjoint Hill operators with complex-valued periodic potentials of the type $V(x)=\sum_{k=1}^{\infty} a_k e^{ikx}$, with $\sum_{k=1}^{\infty}|a_k|<\infty$, have spectra $[0, \infty)$. In this note, we provide an alternative and elementary proof of this result.6 pages; no figure; to appear in Math. NachrMathematical PhysicsOn half-line spectra for a class of non-self-adjoint Hill operatorstext