Electric dipole moments of atoms, molecules, nuclei, and particles

The existence of a nonvanishing electric dipole moment for an elementary particle, atom or molecule, would indicate a violation of time reversal symmetry and parity-symmetry violation. The latter could help resolve the question of the observed matter-antimatter asymmetry in the Universe. This review provides a broad overview of theoretical motivations and interpretations as well as details about experimental techniques, experiments, and prospects.