He is a professor of physics at the University of Washington, where he was director of the Institute for Nuclear Theory during the period 2006–2016 and is now a senior fellow.

He is known for his work on the theory of the composite Higgs boson, the role of the strange quark in dense matter and the phenomenon of kaon condensation, development of the theory of electroweak baryogenesis and other aspects of particle astrophysics, for lattice models with exact supersymmetry, and for the formulation of lattice gauge theory with chiral fermions.

The latter is known as the theory of domain-wall fermions,[1][2][3][4] and is an early example of what has later become known among condensed matter physicists as a topological insulator.

He is a recipient of the Department of Energy Outstanding Junior Investigator Award, the National Science Foundation Presidential Young Investigator Award,[7] and an Alfred P. Sloan Foundation fellowship.

He was married to Ann Nelson, also a theoretical physicist, until her death in a hiking accident in August 2019.