Abstract
The study of quasi-particles formed by the electron-phonon interaction in ionic crystals (the polarons) aroused Feynman's interest in the possibility of finding some connection with superconductivity and for providing a direct application of his formalism of quantum electrodynamics. To calculate the ground state energy of the polaron, Feynman developed a variational method that can be applied to calculations of path integrals and that gave him some pleasure. In this work, Feynman's original 1955 article is analyzed with historical insights that help to understanding his approach to problem solving.
Keywords:
polarons; path integrals; Feynman; history of physics
