GALANTI, GiorgioGiorgioGALANTIRONCADELLI, MARCOMARCORONCADELLI2025-03-102025-03-1020222218-1997http://hdl.handle.net/20.500.12386/36602We 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.ELETTRONICOenArticle10.3390/universe80502532-s2.0-85129516791https://www.mdpi.com/2218-1997/8/5/253http://arxiv.org/abs/2205.00940v1FIS/05 - ASTRONOMIA E ASTROFISICA