String Theory Seminars

Hidden Symmetries of Scattering Amplitudes in Gauge Theories and Gravity (Quantum Spacetime Seminar Series)

by Dr. Florian Loebbert (Humboldt U., Berlin)

Monday, May 7, 2018 from to (Asia/Kolkata)
at A 304
In this talk we discuss two instances of hidden symmetries in four- dimensional scattering amplitudes. Firstly, we motivate how to obtain simple 4d integrable field theories as limits of planar twisted N=4 super Yang- Mills theory. Amplitudes in these new theories are in one-to-one correspondence with Zamolodchikov's fishnet Feynman graphs and generalizations thereof. Their relation to the planar AdS/CFT duality implies that large families of mostly unsolved Feynman integrals inherit a conformal Yangian symmetry. We then show that also tree-level scattering in ordinary Einstein gravity possesses a hidden conformal Lie algebra symmetry. The inspiration for the latter finding originates in soft limits of string theory scattering amplitudes. Curiously, our formulation of this symmetry relies on a manifestly permutation symmetric form of the graviton amplitude.