2134/24699 Jozsef Lorinczi Jozsef Lorinczi Itaru Sasaki Itaru Sasaki Embedded eigenvalues and Neumann–Wigner potentials for relativistic Schrödinger operators Loughborough University 2017 Relativistic Schrodinger operator Non-local operator Neumann-Wigner potentials Embedded eigenvalues Resonances Mathematical Sciences not elsewhere classified 2017-04-11 13:06:09 Journal contribution https://repository.lboro.ac.uk/articles/journal_contribution/Embedded_eigenvalues_and_Neumann_Wigner_potentials_for_relativistic_Schr_dinger_operators/9386726 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.