2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/45622Within the framework of generalized free field theory at nonzero temperature we address the problem of current conservation. The formalism of thermo field dynamics is used to derive a conserved and thermodynamically consistent physical current operator. Consequences for the calculation of photon emission rates from a hot plasma are considered briefly.7 pages, revtex, no figures, fully available at ftp://tpri6c.gsi.de/pub/phenning/h95curc/ and get h95curc.*High Energy Physics - Phenomenologytext