Maxwell stress tensor and the Casimir effect

We evaluate the quantum correlators associated with the Maxwell field vacuum distorted by the presence of plane parallel material surfaces. Regularization is performed through the generalized zeta funtion technique. Results are applied to a local analysis of the atractive and repulsive Casimir effect through Maxwell stress tensor. Surface divergences are shown to cancel out when stresses on both sides of the material surface are taken into account. Since an atom can be considered as a probe of the local distortion of the quantum vacuum, Casimir-Polder interactions between atoms and material surfaces are also considered.