2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/152652The basic ideas and the important role of gauge principles in modern elementary particle physics are outlined. There are three theoretically consistent gauge principles in quantum field theory: the spin-1 gauge principle of electromagnetism and the standard model, the spin-2 gauge principle of general relativity, and the spin-3/2 gauge principle of supergravity. (Dirac Prize lecture, November 1993. Two figures are unavailable, but should not be essential.)18 pagesHigh Energy Physics - TheoryMathematical Physicstext