Alternative derivation of the propagator in polar coordinates by Feynman's physical interpretation of the characteristic function

This article revisits Feynman's characteristic function, and points out the insight and usefulness of his physical interpretation. As an example, the tedious and rather long derivation of the propagator in polar coordinates can be easily and clearly obtained by merely using Feynman's physical intepretation of the characteristic function and some well-known results of central force problem.Physics, MultidisciplinarySCI(E)中国科学引文数据库(CSCD)0ARTICLE5529-5323