Mixed non-gaussianity from axion-gauge field dynamics

Tomohiro Fujita, Ryo Namba, Ippei Obata

Research output: Contribution to journalArticlepeer-review

6 Citations (Scopus)

Abstract

We study scalar-tensor-tensor cross correlation ≤ ζ hh ≤ generated by the dynamics of interacting axion and SU(2) gauge fields during inflation. We quantize the quadratic action and solve the linear equations by taking into account mixing terms in a non-perturbative manner. Combining that with the in-in formalism, we compute contributions from cubic interactions to the bispectrum Bζ hh. We find that the bispectrum is peaked at the folded configuration, which is a unique feature encoded by the scalar mixing and localized production of tensor modes. With our parameter choice, the amplitude of the bispectrum is k6 Bζ hh ∼ 10-16. The unique shape dependence, together with the parity-violating nature, is thus a distinguishing feature to search for in the CMB observables.

Original languageEnglish
Article number044
JournalJournal of Cosmology and Astroparticle Physics
Volume2019
Issue number4
DOIs
Publication statusPublished - 2019 Apr 24
Externally publishedYes

Keywords

  • cosmological perturbation theory
  • gravitational waves and CMBR polarization
  • ination
  • non-gaussianity

ASJC Scopus subject areas

  • Astronomy and Astrophysics

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