Recent experimental advances in positronium research

Positronium is a two-body, leptonic, particle-antiparticle system which possesses self-annihilation channels not directly present in any system studied to date. These features make it ideal for the study of the relativistic, two-body problem in quantum electrodynamics. This review will focus on recent experimental advances in fundamental positronium research. In addition, a less detailed discussion of recent theoretical advances is outlined. The review also contains a fairly detailed historial introduction and a section discussing uses of positronium in research not related to tests of quantum electrodynamics.