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Title: Combined features in the primordial spectra induced by a sudden turn in two-field DBI inflation

We investigate the features generated by a sharp turn along the inflationary trajectory in a two-field model of Dirac-Born-Infeld inflation, where one of the fields is heavy. Distinct features are generated by two different effects: the mixing of the light and heavy modes during the turn, on the one hand, and the resonance between the oscillations along the heavy direction after the turn, on the other hand. Contrary to models with standard kinetic terms, the resonance effect is not strongly suppressed because the action contains derivative interactions. Working in the potential basis, we study the oscillations after the turn and compute the amplitude of the mixing and resonance features in the power spectrum, as well as in the bispectrum for the latter effect. We find that the amplitudes and positions of these combined features obey specific consistency relations, which could be confronted with cosmological data.
Authors:
 [1] ; ;  [2]
  1. Waseda Institute for Advanced Study, Waseda University, Tokyo 169-8050, Japan, (Japan)
  2. APC, CNRS-Université Paris 7, 10 rue Alice Domon et Léonie Duquet, 75205 Paris (France)
Publication Date:
OSTI Identifier:
22375740
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Cosmology and Astroparticle Physics; Journal Volume: 2014; Journal Issue: 11; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; AMPLITUDES; BORN-INFELD THEORY; COSMOLOGICAL INFLATION; OSCILLATIONS; RESONANCE; SPECTRA; TRAJECTORIES