Progress on Ultraviolet Finiteness of Supergravity

TL;DR

Recent advances suggest N=8 supergravity may be ultraviolet finite in four dimensions, supported by multiloop calculations and novel amplitude relations that indicate improved high-energy behavior.

Contribution

The paper summarizes recent multiloop calculations and introduces a modern unitarity method linking gravity and gauge-theory amplitudes, highlighting potential finiteness.

Findings

Evidence of potential ultraviolet finiteness in N=8 supergravity

Development of a unitarity method for multiloop calculations

Discovery of relations between tree-level and loop-level amplitude cancellations

Abstract

In 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.