D ec 1 99 9 Regularized Casimir energy for an infinite dielectric cylin - der subject to light - velocity conservation

The Casimir energy of a dilute dielectric cylinder, with the same light-velocity as in its surrounding medium, is evaluated exactly to first order in ξ 2 = ε 1 − ε 2 ε 1 + ε 2 2 (where ε 1 , ε 2 are the dielectric constants of the cylinder and of its environment), and numerically to higher orders in ξ 2. The first part is carried out using addition formulas for Bessel functions, and no Debye expansions are required.