Scattering by a Nihility Sphere

The concept of nihility as an electromagnetic medium has emerged [1] from the rather extraordinary developments on negatively refracting materials during this decade [2, 3]. Whereas the relative permittivity and relative permeability of vacuum are ǫr = μr = 1, and those of anti– vacuum are ǫr = μr = −1, those of nihility are ǫr = μr = 0. The so–called perfect lens of Pendry [4] is made of anti–vacuum [5], and any perfect lens in the present context is required to simulate nihility [5, 6].