Energy transfer of a quasi-monochromatic wave in an inhomogeneous medium

The paper presents the derivation of more general expressions than those usually obtained for the energy density W, the energy flux density S⃗, and the energy dissipation Γ of a quasi-monochromatic wave. The corrections as computed can be substantial, for example, in an inhomogeneous plasma in the region of frequencies ω for which the drift effects play an important role.