2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/149127We study in detail the structure of the Yangian Y(gl(N)) and of some new Yangian-type algebras called twisted Yangians. The algebra Y(gl(N)) is a `quantum' deformation of the universal enveloping algebra U(gl(N)[x]), where gl(N)[x] is the Lie algebra of gl(N)-valued polynomial functions. The twisted Yangians are quantized enveloping algebras of certain twisted Lie algebras of polynomial functions which are naturally associated to the B, C, and D series of the classical Lie algebras.105 pages, AmSTeX, CMA-MR53-93 (list of references is completed, minor improvements are made)High Energy Physics - Theorytext