2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/109959The general prescription for constructing the continuum limit of a field theory is explained using Wilson's renormalization group. We then formulate the renormalization group in perturbation theory and apply it to the four dimensional phi4 theory and QED.42 pages, lectures given at the APCTP/CQUeST Field Theory Winter School, Feb. 2 to 6, 2006, in Pohang, KoreaHigh Energy Physics - Theorytext