LORINCZI, J. and SASAKI, I., 2017. Embedded eigenvalues and Neumann-Wigner potentials for relativistic Schroedinger operators. Journal of Functional Analysis, 273 (4), pp. 1548-1575.
The existence of potentials for relativistic Schrodinger operators allowing eigenvalues em
bedded in the essential spectrum is a long-standing open problem. We construct Neumann-Wigner type potentials for the massive relativistic Schrodinger operator in one and three dimensions for which an embedded eigenvalue exists. We show that in the non-relativistic limit these potentials converge to the classical Neumann-Wigner and Moses-Tuan potentials, respectively. For the massless operator in one dimension we construct two families of potentials, different by the parities of the (generalized) eigenfunctions, for which an
eigenvalue equal to zero or a zero-resonance exists, dependent on the rate of decay of
the corresponding eigenfunctions. We obtain explicit formulae and observe unusual decay
behaviours due to the non-locality of the operator.
This paper was accepted for publication in the journal Journal of Functional Analysis and the definitive published version is available at http://dx.doi.org/10.1016/j.jfa.2017.03.012