2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/107091A translation invariant N-polaron system is investigated at arbitrary electron-phonon coupling strength, using a variational principle for path integrals for identical particles. An upper bound for the ground state energy is found as a function of the number of spin up and spin down polarons, taking the electron-electron interaction and the Fermi statistics into account. The resulting addition energies and the criteria for multipolaron formation are discussed.22 pages, 5 figures, 1 table, E-mail addresses: jozef.devreese@ua.ac.be, fons.brosens@ua.ac.be, sergei.klimin@ua.ac.beStrongly Correlated Electronstext