Proposed astrophysical test of Lorentz invariance

TL;DR

This paper explores astrophysical tests for Lorentz invariance violation, using cosmic ray data and photon-neutrino time delays, to set bounds on theoretical parameters and identify potential symmetry violations.

Contribution

It proposes new astrophysical methods to test Lorentz invariance violation, linking cosmic ray observations and photon-neutrino time delays to theoretical models.

Findings

Bounds on Lorentz violation parameters from cosmic ray data

Time delay between photons and neutrinos is energy independent

Time delay depends on particle chirality

Abstract

Working in the context of a Lorentz-violating extension of the standard model we show that estimates of Lorentz symmetry violation extracted from ultra-high energy cosmic rays beyond the Greisen-Kuzmin-Zatsepin (GZK) cutoff allow for setting bounds on parameters of that extension. Furthermore, we argue that a correlated measurement of the difference in the arrival time of gamma-ray photons and neutrinos emitted from active galactic nuclei or gamma-ray bursts may provide a signature of possible violation of Lorentz symmetry. We have found that this time delay is energy independent, however it has a dependence on the chirality of the particles involved. We also briefly discuss the known settings where the mechanism for spontaneous violation of Lorentz symmetry in the context of string/M-theory may take place.