On Electromagnetic Scattering from a Penetrable Corner

This article is concerned with the time-harmonic electromagnetic (EM) scattering from a generic inhomogeneous medium. It is shown that an EM medium, whose support has a right corner, scatters every pair of incident EM fields, excluding a possible class of EM fields which are of very particular forms. We prove the result by establishing a stronger result showing the failure of the real-analytic extension across the corner, of certain EM fields satisfying the interior transmission eigenvalue problem. This extends the results of [E. Bl\aasten, L. Päivärinta, and J. Sylvester, Comm. Math. Phys., 331 (2014), pp. 725--753] for the acoustic scattering governed by the scalar Helmholtz equation to the electromagnetic case governed by the vectorial Maxwell system.