Axions of Evil

Abstract

We provide a systematic framework for theories of multiple axions. We discover a novel type of "alignment" that renders even very complex theories analytically tractable. Theories with about 100 axions and random parameters have an exponential number of meta-stable vacua and accommodate a diverse range of inflationary observables. Very light fields can serve as dark matter with the correct abundance. Tunneling from a minimum with large vacuum energy can occur via a thin-wall instanton and be followed by a sufficient period of slow-roll inflation that ends in a vacuum containing axion dark matter and a cosmological constant with a value consistent with observation. Hence, this model can reproduce many macroscopic features of our universe without tuned parameters.