Spontaneous Violation of Lorentz Invariance and Ultra-High Energy Cosmic Rays

TL;DR

This paper suggests that spontaneous violation of Lorentz invariance at high energies, caused by a vector field's vacuum expectation value, could explain ultra-high energy cosmic rays exceeding the GZK cutoff.

Contribution

It introduces a novel mechanism where spontaneous Lorentz violation accounts for ultra-high energy cosmic rays above the GZK cutoff.

Findings

Lorentz invariance may be spontaneously broken at high energies.

This breaking could explain cosmic rays beyond the GZK cutoff.

Implications for cosmology are discussed.

Abstract

We propose that local Lorentz invariance is spontaneously violated at high energies, due to a nonvanishing vacuum expectation value of a vector field \phi^\mu, as a possible explanation of the observation of ultra-high energy cosmic rays with an energy above the GZK cutoff. Certain consequences of spontaneous breaking of Lorentz invariance in cosmology are discussed.