%0 Journal Article %T Exact results for Casimir forces using Surface Impedance: Nonlocal Media %A R. Esquivel %A C. Villarreal %A W. L. Mochan %J Physics %D 2003 %I arXiv %R 10.1103/PhysRevA.68.052103 %X We show that exact results are obtained for the calculation of Casimir forces between arbitrary materials using the concept of surface impedances, obtaining in a trivial way the force in the limit of perfect conductors and also Lifshitz formula in the limit of semi-infinite media. As an example we present a full and rigorous calculation of the Casimir force between two metallic half-spaces described by a hydrodynamic nonlocal dielectric response. %U http://arxiv.org/abs/quant-ph/0306139v1