Low energy Lorentz violation from modified dispersion at high energies

TL;DR

This paper demonstrates that certain modified dispersion relations from quantum gravity theories lead to significant low-energy Lorentz violations detectable in atomic models, challenging the assumption of Lorentz invariance at accessible energies.

Contribution

It shows that quantum gravity-inspired dispersion relations cause observable Lorentz violations at low energies, especially in atomic models like Unruh-DeWitt detectors.

Findings

Polymer quantization predicts Lorentz violation below current collider energies.

Any dispersion function dipping below unity causes low-energy Lorentz violation.

The results challenge the assumption of Lorentz invariance at accessible energy scales.

Abstract

Many quantum theories of gravity propose Lorentz violating dispersion relations of the form $\omega = |k|\, f(|k|/M)$, with recovery of approximate Lorentz invariance at energy scales much below $M$. We show that a quantum field with this dispersion predicts drastic low energy Lorentz violation in atoms modelled as Unruh-DeWitt detectors, for any $f$ that dips below unity somewhere. As an example, we show that polymer quantization motivated by loop quantum gravity predicts such Lorentz violation below current ion collider rapidities.