The Perturbative Ultraviolet Structure of N=4 Supergravity
Prof.Tristan DENNEN(Niels Bohr International Academy & IHÉS)
Amphithéâtre Léon Motchane (Institut des Hautes Etudes Scientifiques)
Amphithéâtre Léon Motchane
Institut des Hautes Etudes Scientifiques
35, route de Chartres
I will present recent calculations of the ultraviolet limit of multi-loop scattering amplitudes in N=4 supergravity. These calculations are performed using a squaring relationship between integrands for Yang-Mills amplitudes and for gravity amplitudes. I will discuss in detail the procedure we use to extract ultraviolet divergences from Feynman integrals, and I will present the three- and four-loop ultraviolet divergences in four-graviton scattering. I will also show how the four-loop divergence might be interpreted in terms of the U(1) duality anomaly of the theory.