2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/20398A path integral representation appropriate for further Monte Carlo simulations is derived for the electron-phonon Holstein model in three spatial dimensions. The model is studied within mean-field theory. Charge density wave and superconducting phase transitions are discussed.Latex file typeset using elsart.cls, 16 pages, 2 figures, submitted to Journal of Physics: Condensed MatterStrongly Correlated ElectronsSuperconductivitytext