Bounds on an energy-dependent and observer-independent speed of light from violations of locality

TL;DR

This paper derives bounds on energy-dependent, observer-independent speed of light models by analyzing their non-local effects, ruling out certain modifications to special relativity at first order in energy over the Planck mass.

Contribution

It provides a novel analysis linking non-local effects to bounds on deformations of special relativity, constraining models with energy-dependent light speed.

Findings

Strong bounds on first-order energy-dependent speed of light models

Non-local effects impose constraints consistent with known particle physics

Certain modifications to special relativity are ruled out at first order

Abstract

We show that models with deformations of special relativity that have an energy-dependent speed of light have non-local effects. The requirement that the arising non-locality is not in conflict with known particle physics allows us to derive strong bounds on deformations of special relativity and rule out a modification to first order in energy over the Planck mass.