Emergent Lorentz invariance from Strong Dynamics: Holographic examples

TL;DR

This paper investigates how Lorentz invariance can emerge at low energies in strongly coupled theories using holography, showing that deviations from relativistic behavior are suppressed and that certain bound states maintain near-light speeds.

Contribution

It demonstrates the emergence of Lorentz invariance in strongly coupled theories via holographic models, analyzing the suppression of deviations and stability of bound state velocities.

Findings

Deviations from Lorentz invariance are power-law suppressed by scale ratios.

Bound state velocities remain close to the emergent speed of light at high energies.

Holographic models illustrate the RG flow towards Lorentz invariance.

Abstract

We explore the phenomenon of emergent Lorentz invariance in strongly coupled theories. The strong dynamics is handled using the gauge/gravity correspondence. We analyze how the renormalization group flow towards Lorentz invariance is reflected in the two-point functions of local operators and in the dispersion relations of the bound states. The deviations of these observables from the relativistic form at low energies are found to be power-law suppressed by the ratio of the infrared and ultraviolet scales. We show that in a certain subclass of models the velocities of the light bound states stay close to the emergent `speed of light' even at high energies. We comment on the implications of our results for particle physics and condensed matter.