The electrodynamics of interacting electrons in anisotropic metals

I discuss the main features of the electrodynamic response of low-dimensional metals both in their broken symmetry, charge density wave and spin density wave states, and above the phase transition in the ''metallic'' state, Both single-particle and collective (phason) excitations can be identified in the broken symmetry states, whereas the metallic state is characterized by strong fluctuation and correlation effects which lead to dramatic deviations from the conventional Drude response.