2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/48315In hot gauge theories a breakdown of the hard thermal loop expansion occurs for light-like external momenta or in the infrared region. In QED where a resummation of ladder diagrams is usually advocated, it is shown that long range magnetic interations involve a broader set of graphs. The consequence is a generalized compensation of the hard modes damping terms at leading order in the infrared limit and near the light-cone. The relevance of the so-called improved hard thermal loop resummation scheme is discussed.7 pages, RevTeX, 2 eps figures. Contribution to the proceedings of the 5th International Workshop on Thermal Field Theories and their Applications, Regensburg (Germany), August 1998. Typos correctedHigh Energy Physics - Phenomenologytext