Boyer and Rohrlich have exchanged arguments, in the context of the classical model of the electron, in favor of and against the standard definition of the electromagnetic field momentum. An exactly soluble model of the electron, with simple Poincaré stresses, is introduced to resolve this issue. It is shown that to determine a part of the total momentum, localized in a finite region of space, the standard definition is more suitable.

• Received 24 January 1983

DOI:https://doi.org/10.1103/PhysRevD.28.2114