Scattering at Planckian Energies

TL;DR

This paper analyzes high-energy forward scattering in 3+1-dimensional quantum gravity, revealing that quantum effects are described by a topological field theory and showing universal behavior akin to 2D string amplitudes, extending previous results.

Contribution

It provides a systematic analysis of quantum gravitational scattering at Planckian energies, demonstrating a topological field theory description and universal amplitude behavior.

Findings

Quantum gravitational effects are described by a topological field theory.

Scattering amplitudes exhibit universal behavior similar to 2D string amplitudes.

Results extend previous work by 't Hooft on high-energy scattering.

Abstract

We give a systematic analysis of forward scattering in 3$+$1-dimensional quantum gravity, at center of mass energies comparable or larger than the Planck energy. We show that quantum gravitational effects in this kinematical regime are described by means of a topological field theory. We find that the scattering amplitudes display a universal behaviour very similar to two dimensional string amplitudes, thereby recovering results obtained previously by 't Hooft. Finally, we discuss the two-particle process in some detail.