Semiclassical Virasoro Symmetry of the Quantum Gravity S-Matrix
arXiv:1406.3312 · doi:10.1007/JHEP08(2014)058
Abstract
It is shown that the tree-level S-matrix for quantum gravity in four-dimensional Minkowski space has a Virasoro symmetry which acts on the conformal sphere at null infinity.
22 pages, 1 figure