BGU Physics Department

Colloquium, Dec. 22nd, 2011

Harmony of scattering amplitudes: from collider physics to supergravity

Zvi Bern, UCLA

Feynman diagrams have long been the basic tool in quantum field theory giving a systematic description of scattering amplitudes. However, they can greatly obscure the beauty and simplicity of scattering amplitudes, introducing complicated unphysical contributions that cancel only at the end of computations. We describe modern ideas allowing us to sneak past Heisenberg's uncertainty principle to reveal a remarkable simplicity in scattering amplitudes. We describe relations between the way gravitons and gluons scatter, crying out for a unification of the sort seen in string theory. These ideas allow us to perform calculations addressing fundamental questions in quantum field theory that would have been extremely difficult, if not impossible, a few years ago. We describestate-of-the-art applications to physics at the Large Hadron Collider and to studies of the compatibility of General Relativity with Quantum Mechanics.