“…This makes the operator H x,λ at least densely defined on H(s, τ, α), although it is not obvious that it lands in H(s, τ, α). We have conjectured in [EFK2,EFK3] (see also [BK2]) that in fact it does, and moreover it extends to a bounded operator which is norm-continuous in x (see Conjecture 2.16 below).…”