Effective gravitational fields in transplanckian scattering

TL;DR

This paper compares quantum S-matrix results with classical General Relativity in high-energy gravitational scattering, showing that leading quantum contributions align with classical metrics.

Contribution

It demonstrates that the leading quantum gravitational fields in transplanckian scattering match classical solutions, bridging quantum and classical gravity descriptions.

Findings

Quantum and classical results agree at leading order

Feynman diagram calculations reproduce classical metrics

Supports the validity of the ACV semiclassical approach

Abstract

After a short introduction to the general Quantum Gravity problem, we compare a result from the S-matrix description of gravitational interaction due to Amati, Ciafaloni and Veneziano (ACV) with classical General Relativity results. In Chapter 1, we introduce the metric produced by a massless particle moving at the speed of light. In Chapter 2, we review ACV's semiclassical approach to gravitation and show some of its result. In Chapter 3, we detail the computation of gravitational field expectation values in a high-energy scattering process, following ACV's prescriptions. In Chapter 4, we analyze our results. The main feature is that the leading contributions to the metric computed in terms of the Feynman diagrams deriving from ACV's model perfectly reproduce classical results.