In what year was the physicist who introduced the 't Hooft operator born?
't Hooft operator In theoretical physics, a 't Hooft operator, introduced by Gerard 't Hooft in the 1978 paper "On the phase transition towards permanent quark confinement", is a dual version of the Wilson loop in which the electromagnetic potential "A" is replaced by its electromagnetic dual "A", where the exterior derivative of "A" is equal to the Hodge dual of the exterior derivative of "A". In d spacetime dimensions, "A" is a (d-3)-form and so the 't Hooft operator is the integral of "A" over a (d-3)-dimensional surface.
Mandelstam variables In theoretical physics, the Mandelstam variables are numerical quantities that encode the energy, momentum, and angles of particles in a scattering process in a Lorentz-invariant fashion. They are used for scattering processes of two particles to two particles. The Mandelstam variables were first introduced by physicist Stanley Mandelstam in 1958.