Gravitons scattering from classical matter

TL;DR

This paper calculates the low energy scattering cross-section of gravitons from classical massive bodies using effective quantum gravity, showing consistency with classical general relativity in the classical limit.

Contribution

It demonstrates that the effective quantum gravity approach reproduces classical general relativity results for graviton scattering from extended bodies.

Findings

The scattering amplitude matches classical predictions for rotating planets and stars.

The cross-section is computed to lowest order in gravitational coupling.

The approach confirms the classical limit of quantum gravity calculations.

Abstract

The low energy scattering of gravitons from a composite extended system, which is made of classical massive bodies, is considered; by using the Feynman rules of effective quantum gravity, the corresponding cross-section is computed to lowest order in powers of the gravitational coupling constant. For the gravitons scattering from a rotating planet or a star, it is shown that the classical limit of the matter-gravitons coupling in the effective quantum gravity lagrangian leads to a low energy scattering amplitude which coincides with the expression obtained in classical general relativity.