Cosmologically safe QCD axion as a present from extra dimension

Masahiro Kawasaki, Masaki Yamada, Tsutomu T. Yanagida

Research output: Contribution to journalArticlepeer-review

14 Citations (Scopus)


We propose a QCD axion model where the origin of PQ symmetry and suppression of axion isocurvature perturbations are explained by introducing an extra dimension. Each extra quark-antiquark pair lives on branes separately to suppress PQ breaking operators. The size of the extra dimension changes after inflation due to an interaction between inflaton and a bulk scalar field, which implies that the PQ symmetry can be drastically broken during inflation to suppress undesirable axion isocurvature fluctuations.

Original languageEnglish
Pages (from-to)12-16
Number of pages5
JournalPhysics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics
Publication statusPublished - 2015 Nov 2
Externally publishedYes

ASJC Scopus subject areas

  • Nuclear and High Energy Physics


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