Non-Gaussianities in multi-field DBI inflation with a waterfall phase transition
arXiv:1207.4410 · doi:10.1103/PhysRevD.86.083503
Abstract
We study multi-field DBI inflation models with a waterfall phase transition. This transition happens for a D3 brane moving in the warped conifold if there is an instability along angular directions. The transition converts the angular perturbations into the curvature perturbation. Thanks to this conversion, multi-field models can evade the stringent constraints that strongly disfavour single field ultra-violet DBI inflation models in string theory. We explicitly demonstrate that our model satisfies current observational constraints on the spectral index and equilateral non-Gaussianity as well as the bound on the tensor to scalar ratio imposed in string theory models. In addition we show that large local type non-Gaussianity is generated together with equilateral non-Gaussianity in this model.
18 pages, 6 figures
References in corpus (19)
- Observational Signatures and Non-Gaussianities of General Single Field Inflation
- Non-Gaussianities in two-field inflation
- Primordial perturbations and non-Gaussianities in DBI and general multi-field inflation
- A Microscopic Limit on Gravitational Waves from D-brane Inflation
- Primordial fluctuations and non-Gaussianities in multi-field DBI inflation
- Multi-brid inflation and non-Gaussianity
- Non-Gaussianities from ekpyrotic collapse with multiple fields
- Spinflation
- Primordial Non-Gaussianity in Multi-Scalar Slow-Roll Inflation
- Comparing Infrared Dirac-Born-Infeld Brane Inflation to Observations
- Gravitational Wave Constraints on DBI Inflation
- On the full quantum trispectrum in multi-field DBI inflation
- Lorentz boost and non-Gaussianity in multi-field DBI-inflation
- Non-Gaussianities in Multifield Inflation: Superhorizon Evolution, Adiabaticity, and the Fate of fnl
- Brane Inflation is Attractive
- Gravitational Wave Constraints on Multi-Brane Inflation
- Local non-Gaussianity from rapidly varying sound speeds
- Dynamics of D3-D7 Brane Inflation in Throats
- Towards multi-field D-brane inflation in a warped throat