Non-Gaussianities in the cosmological perturbation spectrum due to primordial anisotropy II

Anindya Dey, Ely Kovetz, Sonia Paban

Research output: Contribution to journalArticlepeer-review

22 Scopus citations

Abstract

We continue to investigate possible signatures of a pre-inflationary anisotropic phase in two-point and three point correlation functions of the curvature perturbation for high-momentum modes which exit the horizon well after isotropization. The late time dynamics of these modes is characterized by a non-Bunch Davies vacuum state which encodes all the information about initial anisotropy in the background space-time. We observe that, unlike the non-planar momenta, there exist regimes of planar momenta for which scale invariance of the power spectrum is strongly broken. This regime of planar momenta gives rise to enhanced non-Gaussianity in certain squeezed triangle configurations, although the enhancement of the fNL parameter is limited by the breakdown of linear perturbation theory at ''exact planarity". Finally, we demonstrate that for the range of planar modes for which scale invariance of the power spectrum is preserved, non-Gaussianity in the curvature perturbation spectrum is naturally constrained to be extremely small.

Original languageEnglish
Article number055
JournalJournal of Cosmology and Astroparticle Physics
Volume2012
Issue number10
DOIs
StatePublished - 1 Oct 2012
Externally publishedYes

Keywords

  • cosmological parameters from CMBR
  • ination
  • non-gaussianity

Fingerprint

Dive into the research topics of 'Non-Gaussianities in the cosmological perturbation spectrum due to primordial anisotropy II'. Together they form a unique fingerprint.

Cite this