Relaxing the cosmological moduli problem by low-scale inflation

Shu Yu Ho, Fuminobu Takahashi, Wen Yin

Research output: Contribution to journalArticlepeer-review

17 Citations (Scopus)

Abstract

We show that the cosmological abundance of string axions is much smaller than naive estimates if the Hubble scale of inflation, H inf , is sufficiently low (but can still be much higher than the axion masses) and if the inflation lasts sufficiently long. The reason is that the initial misalignment angles of the string axions follow the Bunch-Davies distribution peaked at the potential minima. As a result, the cosmological moduli problem induced by the string axions can be significantly relaxed by low-scale inflation, and astrophysical and cosmological bounds are satisfied over a wide range of the mass without any fine-tuning of the initial misalignment angles. Specifically, the axion with its decay constant f ϕ = 10 16 GeV satisfies the bounds over 10 −18 eV ≲ m ϕ ≲ 10 TeV for H inf ≲ 10 keV-10 6 GeV. We also discuss cases with multiple axions and the QCD axion.

Original languageEnglish
Article number149
JournalJournal of High Energy Physics
Volume2019
Issue number4
DOIs
Publication statusPublished - 2019 Apr 1

Keywords

  • Beyond Standard Model
  • Compactification and String Models
  • Cosmology of Theories beyond the SM
  • Supersymmetric Standard Model

ASJC Scopus subject areas

  • Nuclear and High Energy Physics

Fingerprint Dive into the research topics of 'Relaxing the cosmological moduli problem by low-scale inflation'. Together they form a unique fingerprint.

Cite this