Dispersion forces within the framework of macroscopic QED

Dispersion forces, which material objects in the ground state are subject to, originate from the Lorentz force with which the fluctuating, objectassisted electromagnetic vacuum acts on the fluctuating charge and current densities associated with the objects. We calculate them within the framework of macroscopic QED, considering magnetodielectric objects described in terms of spatially varying permittivities and permeabilities which are complex functions of frequency. The result enables us to give a unified approach to dispersion forces on both macroscopic and microscopic levels.