2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/52425This is a write-up of lectures intended for (under)graduate students. Contents: Scalar Ansatz (KP hierarchy). Fermionic Fock space. Fermi-Bose correspondence. KP hierarchy via free fermions. Formal distributions and locality. Operator product expansion. Vertex algebras. Free fermions. Virasoro algebra in KdV.AMSLaTeX, 28 pages. Lectures given at the 2004 DIAS-TH Winter school on theoretical physics in Dubna, Russia. Last updates and other lecture notes are available at http://thsun1.jinr.ru/~alvladim/qft.htmlHigh Energy Physics - Theorytext