Asymptotic Simplicity and Scattering in General Relativity from Quantum Field Theory

TL;DR

This paper combines quantum field theory and general relativity to analyze the asymptotic behavior of spacetime during compact-object scattering, revealing a stronger breakdown of classical peeling properties due to nonlinear interactions.

Contribution

It introduces a novel approach linking the final-state graviton function in QFT to spacetime metrics, demonstrating a significant deviation from classical peeling predictions at higher orders.

Findings

Peeling property is violated at leading order.

Stronger breakdown of peeling at higher post-Minkowskian orders.

Nonlinear long-range interactions cause deviations from classical expectations.

Abstract

We investigate the fate of asymptotic simplicity in physically relevant settings of compact-object scattering. Using the stress tensor of a two-body system as a source, we compute the spacetime metric in General Relativity at finite observer distance in an asymptotic expansion. To do so, we relate the metric to the final-state graviton one-point function in momentum space, which is computed using perturbative QFT techniques. Both the simple pole and the infrared-related logarithmic branch cut in the virtuality of the external graviton contribute nontrivially. We focus on determining the fall-off behavior of the Newman-Penrose scalars, confirming previous predictions that Sachs's peeling property is violated at leading order in the post-Minkowski expansion. Our analysis at higher orders in the post-Minkowskian expansion reveals a significantly stronger breakdown of the peeling property than previously recognized, which is the result of nonlinear, long-range interactions between localized sources and the surrounding gravitational field.