Extrapolation technique for solution of scattering integral equations

Abstract

The Romberg extrapolation technique, widely used for the evaluation of integrals, is generalised and applied to solving integral equations in scattering theory. The proposed approach makes it possible to obtain accurate results with a very small number of mesh points and to control the error of the approximation. Typical examples of the calculation of phase shifts and singularities of the T matrix (i.e. of the energies of bound, virtual and resonance states) are presented.