2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/26741In this tutorial notes we review a functional bosonization approach in the Keldysh technique to one-dimensional Luttinger liquid in the presence of an impurity.15 pages, 1 figure, Proceedings of LXXXI Les Houches School on "Nanoscopic quantum transport", Les Houches, France, June 28-July 30, 2004Mesoscale and Nanoscale PhysicsDisordered Systems and Neural Networkstext