Three-body forces from a classical nonlinear field

摘要

Forces in the systems of two opposite sign and three identical chargescoupled to the dynamical scalar field of the signum-Gordon model areinvestigated. Three-body force is present, and the exact formula for it isfound. Flipping the sign of one of the two charges changes not only the signbut also the magnitude of the force. Both effects are due to nonlinearity ofthe field equation.