Supergravity and matrix theory do not disagree on multi-graviton scattering

TL;DR

This paper compares multi-graviton scattering amplitudes in eleven-dimensional supergravity and matrix theory, showing that the leading supergravity term matches certain loop contributions in matrix theory, clarifying their agreement.

Contribution

It demonstrates that the leading supergravity amplitude originates from specific loop diagrams in matrix theory, resolving previous discrepancies in multi-graviton scattering comparisons.

Findings

The leading supergravity term is reproduced by matrix theory loop diagrams.

Certain loop contributions in matrix theory do not need to vanish by supersymmetry.

Explicit calculation of the setting sun diagram confirms the agreement.

Abstract

We compare the amplitudes for the long-distance scattering of three gravitons in eleven dimensional supergravity and matrix theory at finite N. We show that the leading supergravity term arises from loop contributions to the matrix theory effective action that are not required to vanish by supersymmetry. We evaluate in detail one type of diagram---the setting sun with only massive propagators---reproducing the supergravity behavior.