@inbook{ab51361ee3614b1abe28557d3ae575f6,
title = "Axions and ALPs: A very short introduction",
abstract = "The QCD axion was originally predicted as a dynamical solution to the strong CP problem. Axion like particles (ALPs) are also a generic prediction of many high energy physics models including string theory. Theoretical models for axions are reviewed, giving a generic multi-axion action with couplings to the standard model. The couplings and masses of these axions can span many orders of magnitude, and cosmology leads us to consider several distinct populations of axions behaving as coherent condensates, or relativistic particles. Light, stable axions are a mainstay dark matter candidate. Axion cosmology and calculation of the relic density are reviewed. A very brief survey is given of the phenomenology of axions arising from their direct couplings to the standard model, and their distinctive gravitational interactions.",
author = "Marsh, {David J.E.}",
note = "Funding Information: complete, (though of course these notes discuss new results of the last two years). I am grateful to Thomas Bachlechner, Laura Covi, Jihn Kim, and Andreas Ringwald for useful discussions. Work at King{\textquoteright}s College London was supported by a Royal Astronomical Society Postdoctoral Fellowship. Research at the University of G{\"o}ttingen is funded by the Alexander von Humboldt Foundation and the German Federal Ministry of Education and Research. Publisher Copyright: {\textcopyright} Proceedings of the 13th Patras Workshop on Axions, WIMPs and WISPs, PATRAS 2017. All rights reserved. Copyright: Copyright 2020 Elsevier B.V., All rights reserved.; 13th Patras Workshop on Axions, WIMPs and WISPs, PATRAS 2017 ; Conference date: 15-05-2017 Through 19-05-2017",
year = "2017",
doi = "10.3204/DESY-PROC-2017-02/marsh_david",
language = "English",
series = "Proceedings of the 13th Patras Workshop on Axions, WIMPs and WISPs, PATRAS 2017",
publisher = "Verlag Deutsches Elektronen-Synchrotron",
pages = "59--74",
editor = "Marios Maroudas",
booktitle = "Proceedings of the 13th Patras Workshop on Axions, WIMPs and WISPs, PATRAS 2017",
}