Ultra High Energy Cosmic Rays and Inflation Relics

TL;DR

This paper reviews how matter creation processes after inflation, such as gravitational creation of superheavy particles and non-thermal phase transitions, could explain ultra high energy cosmic rays beyond the GZK cutoff.

Contribution

It provides a comparative review of two post-inflationary matter creation mechanisms relevant to ultra high energy cosmic rays.

Findings

Gravitational creation of superheavy particles could produce cosmic rays beyond GZK.

Non-thermal phase transitions may lead to topological defect formation affecting cosmic ray origins.

Both mechanisms offer potential explanations for observed ultra high energy cosmic rays.

Abstract

There are two processes of matter creation after inflation that may be relevant to the resolution of the puzzle of cosmic rays observed with energies beyond GZK cut-off: 1) gravitational creation of superheavy (quasi)stable particles, and 2) non-thermal phase transitions leading to formation of topological defects. We review both possibilities.