2013/07/28 by Frank Wilczek
Physics and Astronomy · #Astrophysics and Cosmic Phenomena #Cosmology and Gravitation Theories #Dark Matter and Cosmic Phenomena #astro-ph.CO #hep-ph #hep-th #physics.hist-ph
paper · pdf · doi:10.1088/0264-9381/30/19/193001
23 pages. Solicited review for Classical and Quantum Gravity
arxiv created 2013/07/28 · openalex publication_date 2013/09/04 · arxiv updated 2015/06/16 · openalex created_date 2022/05/12 · openalex updated_date 2026/08/05
Valid ideas that physical reality is vastly larger than human perception of it, and that the perceived part may not be representative of the whole, exist on many levels and have a long history. After a brief general inventory of those ideas and their implications, I consider the cosmological "multiverse" much discussed in recent scientific literature. I review its theoretical and (broadly) empirical motivations, and its disruptive implications for the traditional program of fundamental physics. I discuss the inflationary axion cosmology, which provides an example where firmly rooted, plausible ideas from microphysics lead to a well-characterized "mini-multiverse" scenario, with testable phenomenological consequences.