2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/224888We employ a non-linear sigma model defined on a Keldysh contour to study the current and the current noise in a diffusive micro-bridge in the presence of electron-electron interactions. Out of equilibrium the fluctuation-dissipation theorem (FDT) does not apply, hence these two quantities are not simply interrelated. For a two-dimensional electron gas (2DEG) we obtain logarithmic singularities in the low frequency limit. PACS Nos. 71.10.Ay, 71.23.An, 73.50.TdSubmitted to the proceedings of 36 Renconters de Moriond "Electronic correlations: from meso- to nano-physics". One figure addedMesoscale and Nanoscale PhysicsDisordered Systems and Neural Networkstext