2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/221354The purpose of this article is to present a short review of local conformal symmetry in curved 4d space-time. Furthermore we discuss the conformal anomaly and anomaly-induced effective actions. Despite the conformal symmetry is always broken at quantum level, it may be a basis of useful and interesting approximations for investigating quantum corrections.18 pages, LaTeX. Talk presented at the Fifth International Conference on Mathematical Methods in Physics, 24 - 28, April 2006, Rio de Janeiro, Brazil. To be published by PoS/JHEPHigh Energy Physics - Theorytext