Primordial fluctuations and non-Gaussianities in multi-field DBI inflation

by Dr Daniele Steer (Astroparticles and Cosmology (APC Paris))

Thursday 26 Jun 2008, 16:00 → 17:00 Europe/Brussels

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In this talk we discuss multi-field inflation, and more specifically Dirac-Born-Infeld (DBI) inflation with multiple scalar fields. In this model we show that adiabatic and entropy modes propagate with a common effective sound speed. In the small sound speed limit, we show that the amplitude of the entropy modes is much higher than that of the adiabatic mode. We show that this could strongly affect the observable curvature power spectrum as well as the amplitude of non-Gaussianities, although their shape remains as in single-field DBI inflation.