Casimir effects for charged particles

The theory of forces due to quantum electrodynamic field fluctuations are of great consequence in condensed-matter physics and chemistry, and are routinely applied to polarizable media to explain long-ranged van der Waals forces. Less well studied are the Casimir forces on particles with a net charge. Some examples of the charged-particle case are discussed here. In particular, methods are explored for treating the infrared photon ‘‘divergences’’ which arise from the ease with which an accelerated charged particle emits radiation.