Axion-like Particles Implications for High-Energy Astrophysics

TL;DR

This paper provides a comprehensive, accessible overview of axion-like particles (ALPs) and their significance in high-energy astrophysics, highlighting potential astrophysical evidence for ALPs from diverse phenomena.

Contribution

It offers a pedagogical, self-contained review of ALPs in high-energy astrophysics, including two hints of specific ALPs from different astrophysical contexts.

Findings

Identification of two astrophysical hints for specific ALPs

Broad energy range analysis from MeV to TeV energies

Accessible review suitable for non-specialists

Abstract

We offer a pedagogical introduction to axion-like particles (ALPs) as far as their relevance for high-energy astrophysics is concerned, from a few MeV to 1000 TeV. This review is self-contained, in such a way to be understandable even to non-specialists. Among other things, we discuss two strong hints at a specific ALP that emerge from two very different astrophysical situations. More technical matters are contained in three Appendices.