A Microscopic Recoil Model for Light-Cone Fluctuations in Quantum Gravity

TL;DR

This paper introduces a microscopic model for light-cone fluctuations caused by quantum-gravitational recoil effects, predicting energy-dependent photon delays and stochastic arrival time spreads, which can be tested through astrophysical observations.

Contribution

It develops a novel microscopic recoil model incorporating string theory defects to explain quantum light-cone fluctuations and their observable consequences.

Findings

Derived an energy-dependent refractive index for photons.

Predicted stochastic spread in photon arrival times.

Linked quantum-gravitational effects to astrophysical observations.

Abstract

We present a microscopic model for light-cone fluctuations ``in vacuo'', which incorporates a treatment of quantum-gravitational recoil effects induced by energetic particles. Treating defects in space-time as solitons in string theory, we derive an energy-dependent refractive index and a stochastic spread in the arrival times of mono-energetic photons due to quantum diffusion through space-time foam, as found previously using an effective Born-Infeld action. Distant astrophysical sources provide sensitive tests of these possible quantum-gravitational phenomena.