A projection operator technique for solution of relativistic wave equation on non-compact group: the case of a charged vector-boson

A projection operator technique for solution of relativistic wave equation on non-compact group has been proposed. This technique was applied to the construction of wave equations for charged vector boson in a potential field. The equations were shown to approximately describe a hydrogen-like atom and allow estimating of relativistic corrections such as a fine structure of hydrogen atom lines with high accuracy.