2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/18648We compute the DC conductance for a homogeneous sine-Gordon model and an impurity system of Luttinger liquid type by means of the thermodynamic Bethe ansatz and standard potential scattering theory. We demonstrate that unstable particles and resonances in impurity systems lead to a sharp increase of the conductance as a function of the temperature, which is characterized by the Breit-Wigner formula.5 pages Latex, 1 figure replaced, version to appear in J. Phys. CCondensed MatterHigh Energy Physics - Theorytext