SCATTERING OF MAXWELL'S EQUATIONS WITH A LEONTOVICH BOUNDARY 
CONDITION IN AN INHOMOGENEOUS MEDIUM: A SINGULAR PERTURBATION PROBLEM

      by H. Ammari, C. Latiri-Grouz and J.-C. N\'ed\'elec

The limiting behavior of the unique solution to the scattering
problem for the Maxwell equations with a Leontovich boundary condition in
an inhomogeneous medium  as the impedance goes to zero is investigated.
Making use of a Hodge decomposition lemma, it is shown  that the Leontovich
boundary condition leads to  a singular perturbation problem for only the 
scalar unknown in the Hodge decomposition of the magnetic field. The use of
higher order finite elements is then necessary to achieve a sufficient a
ccuracy of this quantity.

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