Axion Poltergeist
Abstract
Rotations of axion fields in the early universe can produce dark matter and the matter-antimatter asymmetry of the universe. We point out that the rotation can generate an observable amount of a stochastic gravitational-wave (GW) background. It can be doubly enhanced in a class of models in which the equation of state of the rotations rapidly changes from a non-relativistic matter-like one to a kination-like one by 1) the so-called poltergeist mechanism and 2) slower redshift of GWs compared to the axion kination fluid. In supersymmetric UV completion, future GW observations can probe the supersymmetry-breaking scale up to GeV even if the axion does not directly couple to the Standard Model fields.
Cite
@article{arxiv.2305.14242,
title = {Axion Poltergeist},
author = {Keisuke Harigaya and Keisuke Inomata and Takahiro Terada},
journal= {arXiv preprint arXiv:2305.14242},
year = {2023}
}
Comments
7 pages, 4 figures (Supplemental Material: 13 pages, 3 figures), v2: version published in PRD letter (except for the title). minor revision