2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/52134Planarity was introduced by 't Hooft in his topological classification of diagrams in the large-N limit of U(N) gauge theories. Planarity also occurs in noncommutative field theories where amplitudes possess invariance only under cyclic permutations, a feature inherited from the parent string theory. In noncommutative gauge theories both kinds of planarity merge in a context which turns out to be particularly intriguing in the two-dimensional case where gauge invariant correlators can be explicitly computed.LaTeX, 8 pages, no figures. Talk presented by A. Bassetto at the Light-Cone Workshop LC03 "Hadrons and beyond", Durham (U.K.), August 2003High Energy Physics - Theorytext