Vaupel, T.T.Vaupel2022-03-122022-03-122013https://publica.fraunhofer.de/handle/publica/38304810.1109/APS.2013.6711008This contribution deals with some investigations about the convergence behavior of the group interaction integrals within a so-called Thin stratified medium fast multipole approach. Although first formulations of this type of fast integral equation solver were presented more than 10 years ago [2], no detailed convergence considerations of the pertinent group interaction integrals on the vertical branch cut have been published so far. With the known convergence properties, subsequently a robust and optimized solution behavior of the overall solver framework can be achieved using e.g. special quadrature techniques.en621conference paper