Frank Wilczek, Institute for Advanced Study, Princeton, USA (at the time of the award)
for his contributions to the development of theoretical physics. In 1973 he was one of the discoverers of the phenomenon of "asymptotic freedom" in non-Abelian gauge theories. This fundamental observation - that the effective interaction at short distances becomes weak, even in strongly interacting systems - led to the development of a realistic model for hadron physics. In particular, it provided an explanation of scaling and its logarithmic corrections in hadron physics at high energies. Asymptotic freedom has become a cornerstone of the Standard Model of elementary particles and of the theoretical extensions of this model that aim to unify the fundamental forces.
Wilczek has also made important contributions to the study of particle-like excitations in 2-dimensional systems that obey "fractional statistics". These particles, for which he coined the name "anyons" are now recognized to have a role in phenomena such as the fractional quantum Hall effect.