Astronomy and Astrophysics – Astrophysics – Cosmology and Extragalactic Astrophysics
Scientific paper
2011-08-18
JCAP 10 (2011) 027
Astronomy and Astrophysics
Astrophysics
Cosmology and Extragalactic Astrophysics
v1: 25 pages, including tables, an appendix and references. v2: minor clarifications about the lowest-order consistency relati
Scientific paper
10.1088/1475-7516/2011/10/027
Galileon fields arise naturally from the decoupling limit of massive gravities, and possess special self-interactions which are protected by a spacetime generalization of Galilean symmetry. We briefly revisit the inflationary phenomenology of Galileon theories. Working from recent computations of the fluctuation Lagrangian to cubic order in the most general model with second-order equations of motion, we show that a distinct shape is present but with suppressed amplitude. A similar shape has been found in other higher-derivative models. It may be visible in a theory tuned to suppress the leading-order shapes, or if the overall bispectrum has large amplitude. Using a partial-wave expansion of the bispectrum, we suggest a possible origin for the frequent appearance of this shape. It follows that models with very disparate microphysics can produce very similar bispectra. We argue that it may be more profitable to distinguish these models by searching for relations between the amplitudes of these common shapes. We illustrate this method using the example of DBI and k-inflation.
Ribeiro Raquel H.
Seery David
No associations
LandOfFree
Decoding the bispectrum of single-field inflation does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Decoding the bispectrum of single-field inflation, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Decoding the bispectrum of single-field inflation will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-107577