Resonant non-Gaussianity with equilateral properties
arXiv:1211.0070 · doi:10.1088/1475-7516/2013/04/040
Abstract
We discuss the effect of superimposing multiple sources of resonant non-Gaussianity, which arise for instance in models of axion inflation. The resulting sum of oscillating shape contributions can be used to "Fourier synthesize" different non-oscillating shapes in the bispectrum. As an example we reproduce an approximately equilateral shape from the superposition of oscillatory contributions with resonant shape. This implies a possible degeneracy between the equilateral-type non-Gaussianity typical of models with non-canonical kinetic terms, such as DBI inflation, and an equilateral-type shape arising from a superposition of resonant-type contributions in theories with canonical kinetic terms. The absence of oscillations in the 2-point function together with the structure of the resonant -point functions, imply that detection of equilateral non-Gaussianity at a level greater than the PLANCK sensitivity of will rule out a resonant origin. We comment on the questions arising from possible embeddings of this idea in a string theory setting.
34 pages, 5 figures. Version 2: minor clarifications added, typos fixed
References in corpus (12)
- Observational Signatures and Non-Gaussianities of General Single Field Inflation
- Primordial Non-Gaussianities from Inflation Models
- Large Nongaussianity in Axion Inflation
- Generation and Characterization of Large Non-Gaussianities in Single Field Inflation
- Primordial perturbations and non-Gaussianities in DBI and general multi-field inflation
- The shape of primordial non-Gaussianity and the CMB bispectrum
- Trapped Inflation
- 21-cm Background Anisotropies Can Discern Primordial Non-Gaussianity
- Oscillations in the inflaton potential?
- Effective field theory of weakly coupled inflationary models
- Non-Perturbative Corrections and Modularity in N=1 Type IIB Compactifications
- Resonant Trispectrum and a Dozen More Primordial N-point functions