Mathematically, a Yang–Mills instanton is a self-dual or anti-self-dual connection in a principal bundle over a four-dimensional Riemannian manifold that plays the role of physical space-time in non-abelian gauge theory.
Pomeranchuk Prize 2007 for remarkable achievements in quantum field theory, such as instanton solutions in QCD, and deep insights in two-dimensional conformal string theory.
Drinfeld introduced the notion of a quantum group (independently discovered by Michio Jimbo at the same time) and made important contributions to mathematical physics, including the ADHM construction of instantons, algebraic formalism of the Quantum inverse scattering method, and the Drinfeld–Sokolov reduction in the theory of solitons.