Cosmic-ray propagation in extragalactic space and secondary messengers

TL;DR

This paper reviews cosmic-ray propagation in extragalactic space, emphasizing interactions with background photons and analytical methods to compute cosmic-ray fluxes at Earth, contributing to understanding high-energy astrophysical phenomena.

Contribution

It provides an analytical framework for modeling cosmic-ray interactions with background photons, including heavy nuclei, and calculates expected fluxes at Earth, complementing existing lecture content.

Findings

Analytical methods for cosmic-ray flux computation

Interactions of cosmic rays with background photons

Propagation effects on heavy nuclei

Abstract

These notes summarize the lectures about "Cosmic-ray propagation in extragalactic space and secondary messengers", focusing in particular on the interactions of cosmic-ray particles with the background photons in the Universe, including nuclear species heavier than hydrogen, and on the analytical computation of the expected cosmic-ray fluxes at Earth. The lectures were held at the Course 208 of the International School of Physics "Enrico Fermi" on "Foundations of Cosmic-Ray Astrophysics", in Varenna (Como, Italy) from June 23rd to June 29th, 2022. These notes are complementary to the content of the lectures held by Pasquale Dario Serpico at the same school.