2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/25921A rigorous and simple perturbative proof of Luttinger's theorem is sketched for Fermi liquids in two and three dimensions. It is proved that in the finite volume, the quasi-particle density is independent of the interaction strength. The thermodynamic limit is then controlled to all orders in perturbation theory.7 pagesStatistical MechanicsStrongly Correlated Electronstext