Uniqueness of the inverse scattering problem for a chiral obstacle

This paper deals with the inverse scattering problem to determine the shape of a chiral obstacle immersed in achiral free space from the knowledge of the scattered wave. A variational equation is established for the corresponding direct scattering problem. Then, under appropriate assumptions, it is shown that the chiral obstacle is uniquely determined by the far field patterns of all incident waves with a fixed wave number.