The Schwinger action principle for classical systems* *Contribution to the special collection ‘Koopman methods in classical and quantum-classical mechanics’

Abstract

We use the Schwinger action principle to obtain the equations of motion in the Koopman–von Neumann operational version of classical mechanics. We restrict our analysis to non-dissipative systems. We show that for velocity-independent forces the Schwinger action principle can be interpreted as a variational principle.