Quantum Gravity phenomenology: achievements and challenges

TL;DR

This paper reviews recent progress in quantum gravity phenomenology, focusing on how ultra-high-energy cosmic rays constrain deviations from Lorentz invariance and models of space-time foam, highlighting achievements and future challenges.

Contribution

It provides a comprehensive review of experimental constraints on quantum gravity effects, especially Lorentz invariance violations, from cosmic ray observations and discusses future research directions.

Findings

Strong constraints on Lorentz invariance violations from cosmic ray data

First observational bounds on space-time foam models

Advances in testing quantum gravity phenomenology

Abstract

Motivated by scenarios of quantum gravity, Planck-suppressed deviations from Lorentz invariance are expected at observable energies. Ultra-High-Energy Cosmic Rays, the most energetic particles ever observed in nature, yielded in the last two years strong constraints on deviations suppressed by $O(E^{2}/\Mpl^{2})$ and also, for the first time, on space-time foam, stringy inspired models of quantum gravity. We review the most important achievements and discuss future outlooks.