Computation of Scattering Matrices and their Derivatives for Waveguides

Abstract: This paper describes the calculation of the stationary scattering matrix and its derivatives for Euclidean waveguides. This is an adaptation and extension to a procedure developed by Levitin and Strohmaier which was used to compute the stationary scattering matrix \cite{alexnew}. On Euclidean waveguides, the scattering matrix can be meromorphically continued from the complex plane to a Riemann surface with a countably infinite number of sheets. We describe in detail how we have dealt with this. In addition, our algorithm is also able to calculate arbitrarily high derivatives. In the final section, we will present the results of some numerical calculations obtained using this method.