Comparative Study of Spherical Electromagnetic Black Holes with Positive and Negative Refractive Indexes

The problem of plane electromagnetic wave scattering by a spherical absorber of black hole type with radial profile of dielectric permittivity and magnetic permability in the shell chosen in the form ~1/r2 and with constant permittivity and permeability in the central region is considered. The problem in rigorous formulation is solved both analytically for a basic model of the absorber and numerically using the one-dimensional method of finite elements for a modified model. Absorption efficiency and radar cross-section are presented for the black holes with positive and negative refractive indexes, and comparison of them is carried out for a number of values of the absorber's parameters.