Galerkin Method for the Scattering Problem of a Slit

In this paper, the scattering problem of a slit is considered. By use of the exact Dirichlet-to-Neumann map and the continuity of the total field on the slit, we reformulate this problem to an operator equation. The well-posedness of the solution is proved. We apply Galerkin method to solve this operator equation numerically and prove the convergence of the numerical solution. Finally some computational examples are presented to show the effectiveness of our method.