Conditions for the spectrum associated with an asymptotically straight leaky wire to comprise the interval (??, ?)

Abstract

We consider a quantum (or leaky) wire in the plane, and the wire supports a singular attraction which becomes large at distant points on the wire. An analogous regular potential arises from the motion of a hydrogen atom in an electric field. We prove that, as in the regular case, the spectrum is the whole of (??, ?)