Ellipticity of the electric field integral equation for absorbing media and the convergence of the Rao–Wilton–Glisson method

The operator of the electric field integral equation is proved to be elliptic in the case of a flat screen and absorbing media. The method of quadratic forms is applied. As a result, the Rao–Wilton–Glisson method is shown to converge in the case of a flat screen in an absorbing medium.