RT Journal Article T1 Level shift under the influence of relativistic point interaction potentials A1 Méndez Martín, María Bianchi A1 Domínguez-Adame Acosta, Francisco AB Level shift of Dirac particles under the influence of point interaction potentials has been determined. A green function method is used to obtain closed expressions for the level shift and perturbed wavefunctions, provided that the corresponding eigenvalue problem without point interaction potentials can be solved exactly. Several applications are discussed in detail. PB IOP Publishing SN 0305-4470 YR 1992 FD 1992-04-07 LK https://hdl.handle.net/20.500.14352/58994 UL https://hdl.handle.net/20.500.14352/58994 LA eng NO © 1992 IOP Publishing Ltd.The authors wish to thank E MaciA for helpful comments and Dr J Dittrich for sending his paper prior to publication. DS Docta Complutense RD 27 dic 2025