2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/58059This is a very brief introduction to Wilson's Renormalization Group with emphasis on mathematical developments.17 pages, AMS LaTeX. Contribution to the Encyclopedia of Mathematical Physics (Elsevier, 2006). Typos, journal reference correctedMathematical PhysicsHigh Energy Physics - Theory81T08; 82B05; 37D20text