Temperature dependence of the Casimir effect between metallic mirrors - art. no. 012110

We calculate the Casimir force and free energy for plane metallic mirrors a t nonzero temperature. Numerical evaluations an given with temperature and conductivity effects treated simultaneously. The results are compared with the approximation where both effects an treated independently and the corre ctions simply multiplied. The deviation between the exact and approximated results takes the form of a temperature dependent function for which an ana lytical expression is given. The knowledge of this function allows simple e stimations that are accurate below the 1% level.