Resurrecting Low-Mass Axion Dark Matter Via a Dynamical QCD Scale

Abstract

In the framework where the strong coupling is dynamical, the QCD sector may confine at a much higher temperature than it would in the Standard Model, and the temperature-dependent mass of the QCD axion evolves in a non-trivial way. We find that, depending on the evolution of ${\Lambda }_{\mathrm{QCD}}$, the axion field may undergo multiple distinct phases of damping and oscillation leading generically to a suppression of its relic abundance. Such a suppression could therefore open up a wide range of parameter space, resurrecting in particular axion dark-matter models with a large Peccei-Quinn scale $f_a\gg 10^{12}\mathrm{GeV}$, i.e., with a lighter mass than the standard QCD axion.

17 pages, 5 figures, match the published version

References in corpus (5)

• Search for axion-like dark matter with ferromagnets
• Axion cold dark matter in view of BICEP2 results
• QCD Baryogenesis
• DANCE: Dark matter Axion search with riNg Cavity Experiment
• Dark Matter Freeze Out during an Early Cosmological Period of QCD Confinement

Cited by in corpus (9)

• Axion Dark Matter in the Time of Primordial Black Holes
• New opportunities for axion dark matter searches in nonstandard cosmological models
• Dark Matter Axions in the Early Universe with a Period of Increasing Temperature
• Altered Axion Abundance from a Dynamical Peccei-Quinn Scale
• A Light QCD Axion with Hilltop Misalignment
• Reduced Axion Abundance from an Extended Symmetry
• Dark Matter Freeze-out during $\mathrm{SU}(2{)}_{\mathrm{L}}$ Confinement
• Cosmological Stasis from Field-Dependent Decay
• Axion dark matter with not quite black hole domination