The covariant electromagnetic Casimir effect for real conducting spherical shells

Abstract

Using the covariant electromagnetic Casimir effect (recently introduced for real conducting cylindrical shells) 1 (Razmi, Fadaei. Nucl. Phys. B 2009, 814, 582), the Casimir force experienced by a spherical shell, under Dirichlet boundary condition, is calculated. The renormalization procedure is based on the plasma cut-off frequency for real conductors. The real case of a gold (silver) sphere is considered and the corresponding electromagnetic Casimir force is computed. In the covariant approach, there is no decomposition of fields to TE and TM modes; thus, we do not need to consider the Neumann boundary condition in parallel to the Dirichlet problem and then add their corresponding results.