  While metamaterials offer the potential to realize Tamm mediums which
represent vacuous spacetime subjected to gravitational fields, practical
formulations for suitable metamaterials have not hitherto been developed. This
matter is addressed by establishing a metamaterial formulation for the Tamm
medium representing Schwarzschild-(anti-)de Sitter spacetime. Our formulation
is remarkably simple and does not involve a complex nanostructure of the type
that is often associated with metamaterials. Instead it is based on the
homogenization of only isotropic dielectric and isotropic magnetic component
mediums, which are distributed randomly as oriented spheroidal particles. Using
the inverse Bruggeman homogenization formalism, we demonstrated that a wide
range of constitutive parameter values for the Tamm medium may be accessed
through varying the particle shape, volume fraction or relative permittivity
and relative permeability of the component mediums. The presented formulation
is appropriate for the regions of spacetime which lie outside the event horizon
for Schwarzschild spacetime and inside the event horizon for de Sitter
spacetime; there are no such restrictions for anti-de Sitter spacetime.
