English

Improved hot dark matter bound on the QCD axion

High Energy Physics - Phenomenology 2022-11-09 v1 Cosmology and Nongalactic Astrophysics

Abstract

We strengthen the cosmological bound on the axion mass, by solving the momentum-dependent Boltzmann equations for axion-pion scatterings and by using a phenomenological production rate derived from pion-pion scattering data, overcoming the breakdown of chiral perturbation theory. Using present cosmological datasets we obtain ma0.24 eVm_a\leq 0.24~\text{eV}. To further improve the bound and exploit the reach of upcoming cosmological surveys, reliable non-perturbative calculations above the QCD crossover are needed.

Keywords

Cite

@article{arxiv.2211.03799,
  title  = {Improved hot dark matter bound on the QCD axion},
  author = {Alessio Notari and Fabrizio Rompineve and Giovanni Villadoro},
  journal= {arXiv preprint arXiv:2211.03799},
  year   = {2022}
}

Comments

6+8 pages, 7 figures

R2 v1 2026-06-28T05:21:41.399Z