2013年6月
Localized features in non-Gaussianity from heavy physics
Journal of Cosmology and Astroparticle Physics
- ,
- 巻
- 2013
- 号
- 6
- 開始ページ
- 031
- 終了ページ
- 記述言語
- 英語
- 掲載種別
- 研究論文(学術雑誌)
- DOI
- 10.1088/1475-7516/2013/06/031
We discuss the possibility that we could obtain some hints of the heavy physics during inflation by analyzing local features of the primordial bispectrum. A heavy scalar field could leave large signatures in the primordial spectra through the parametric resonance between its background oscillation and the fluctuations. Since the duration of the heavymode oscillations is finite, the effect of the resonance is localized in momentum space. In this paper, we show that the bispectrum is amplified when such a resonance occurs, and that the peak amplitude of the feature can be O(101-2), or as large as O(105) depending on the type of interactions. In particular, the resonance can give large contributions in finitely squeezed configurations, while the bispectrum cannot be large in the exact squeezed limit. We also find that there is a relation between the scales at which the features appear in the bispectrum and the power spectrum, and that the feature in the bispectrum can be much larger than that in the power spectrum. If correlated features are observed at characteristic scales in the primordial spectra, it will indicate the presence of heavy degrees of freedom. By analyzing these features, we may be able to obtain some information on the physics behind inflation. © 2013 IOP Publishing Ltd and Sissa Medialab srl.
- リンク情報
- ID情報
-
- DOI : 10.1088/1475-7516/2013/06/031
- ISSN : 1475-7516
- ORCIDのPut Code : 15271070
- arXiv ID : arXiv:1303.3839
- SCOPUS ID : 84880677734