John H. Schwarz, California Institute of Technology, Pasadena, USA, and
Michael B. Green, Queen Mary College, London, UK (at the time of the award)
for their basic contributions to the development of superstring theory. Most significant was their discovery that chiral gauge anomalies are absent for a class of ten dimensional superstring theories. This provided a strong indication that superstring theory with a specific gauge symmetry may provide a consistent unified quantum theory of the fundamental forces including gravity. It led to an explosion of interest in string theory which has already spurred remarkable advances both in mathematical physics and in pure mathematics.