2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/221739In this lecture we summarize recent calculations pointing to the possible ultraviolet finiteness of N = 8 supergravity in four dimensions. We outline the modern unitarity method, which enables multiloop calculations in this theory and allows us to exploit a remarkable relation between tree-level gravity and gauge-theory amplitudes. We also describe a link between observed cancellations at loop level and improved behavior of tree-level amplitudes under large complex deformations of momenta.Invited lecture at International School of Subnuclear Physics, 46th Course, Erice Sicily, August 29-September 7, 2008. 20 pages, 8 figures, LaTeX, v2 references correctedHigh Energy Physics - TheoryGeneral Relativity and Quantum CosmologyHigh Energy Physics - Phenomenologytext