  A technique for evaluating the electromagnetic Casimir energy in situations
involving spherical or circular boundaries is presented. Zeta function
regularization is unambiguously used from the start and the properties of
Bessel and related zeta functions are central. Nontrivial results concerning
these functions are given. While part of their application agrees with previous
knowledge, new results like the zeta-regularized electromagnetic Casimir energy
for a circular wire are included.

High Energy Physics - Theory