The Schwarzschild-Tangherlini metric from scattering amplitudes in various dimensions

TL;DR

This paper derives the Schwarzschild-Tangherlini metric from scattering amplitudes in various dimensions, explicitly calculating up to three-loop order and fourth post-Minkowskian order, revealing the role of classical contributions and divergences.

Contribution

It introduces a method to extract classical gravitational metrics from multi-loop scattering amplitudes across different dimensions, including divergence cancellation and coordinate transformations.

Findings

Explicit metric expansion up to 4th post-Minkowskian order

Derivation of classical contributions from multi-loop amplitudes

Ultraviolet divergences handled via higher-derivative couplings

Abstract

We derive the static Schwarzschild-Tangherlini metric by extracting the classical contributions from the multi-loop vertex functions of a graviton emitted from a massive scalar field. At each loop orders the classical contribution is proportional to a unique master integral given by the massless sunset integral. By computing the scattering amplitudes up to three-loop order in general dimension, we explicitly derive the expansion of the metric up to the fourth post-Minkowskian order $O(G_N^4)$ in four, five and six dimensions. There are ultraviolet divergences that are cancelled with the introduction of higher-derivative non-minimal couplings. The standard Schwarzschild-Tangherlini is recovered by absorbing their effects by an appropriate coordinate transformation induced from the de Donder gauge condition.