Ultra High Energy Cosmic Rays and Inflation

TL;DR

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

Contribution

It introduces and compares two post-inflation matter creation mechanisms as potential solutions to the ultra-high-energy cosmic ray puzzle.

Findings

Gravitational creation of superheavy particles could produce ultra-high-energy cosmic rays.

Non-thermal phase transitions may lead to topological defects contributing to cosmic ray flux.

Both mechanisms offer plausible explanations for observations beyond the GZK limit.

Abstract

Two processes of matter creation after inflation: 1) gravitational creation of superheavy (quasi)stable particles, and 2) non-thermal phase transitions leading to formation of topological defects, may be relevant to the resolution of the puzzle of cosmic rays observed with energies beyond GZK cut-off. Both possibilities are reviewed in this talk.