Scale-dependent hemispherical asymmetry from general initial state during inflation

Hassan Firouzjahi, Jinn Ouk Gong, Mohammad Hossein Namjoo

Research output: Contribution to journalArticlepeer-review

10 Scopus citations


We consider a general initial state for inflation as the mechanism for generating scale-dependent hemispherical asymmetry. An observable scale-dependent non-Gaussianity is generated that leads to observable hemispherical asymmetry from the super-horizon long mode modulation. We show that the amplitude of dipole asymmetry falls off exponentially on small angular scales which can address the absence of dipole asymmetry at these scales. In addition, depending on the nature of non-vaccum initial state, the amplitude of the dipole asymmetry has oscillatory features which can be detected in a careful CMB map analysis. Furthermore, we show that the non-vacuum initial state provides a natural mechanism for enhancing the super horizon long mode perturbation as required to generate the dipole asymmetry.

Original languageEnglish
Article number037
JournalJournal of Cosmology and Astroparticle Physics
Issue number11
StatePublished - 1 Nov 2014

Bibliographical note

Publisher Copyright:
© 2014 IOP Publishing Ltd and Sissa Medialab srl.


  • CMBR theory
  • Inflation
  • Non-gaussianity
  • Physics of the early universe


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