Non-Gaussianity in single field models without slow-roll
arXiv:1102.0275 · doi:10.1103/PhysRevD.83.103511
Abstract
We investigate non-Gaussianity in general single field models without assuming slow-roll conditions or the exact scale-invariance of the scalar power spectrum. The models considered include general single field inflation (e.g. DBI and canonical inflation) as well as bimetric models. We compute the full non-Gaussian amplitude, its size fnl, its shape, and the running with scale n_{NG}. In doing so we show that observational constraints allow significant violations of slow roll conditions and we derive explicit bounds on slow-roll parameters for fast-roll single field scenarios. A variety of new observational signatures is found for models respecting these bounds. We also explicitly construct concrete model implementations giving rise to this new phenomenology.
28 pages + appendices, 6 figures, References and minor comments added in revised version
References in corpus (35)
- Five-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Cosmological Interpretation
- Observational Signatures and Non-Gaussianities of General Single Field Inflation
- New Ekpyrotic Cosmology
- Generation and Characterization of Large Non-Gaussianities in Single Field Inflation
- Effects of Scale-Dependent Non-Gaussianity on Cosmological Structures
- Non-Gaussianities in two-field inflation
- Primordial perturbations and non-Gaussianities in DBI and general multi-field inflation
- On the consistency relation of the 3-point function in single field inflation
- Non-Gaussianity in the modulated reheating scenario
- The shape of primordial non-Gaussianity and the CMB bispectrum
- Generating Ekpyrotic Curvature Perturbations Before the Big Bang
- Primordial fluctuations and non-Gaussianities in multi-field DBI inflation
- On causality and superluminal behavior in classical field theories. Applications to k-essence theories and MOND-like theories of gravity
- Multiple field inflation
- Scale-dependent non-Gaussianity probes inflationary physics
- A numerical study of non-gaussianity in the curvaton scenario
- Folded Resonant Non-Gaussianity in General Single Field Inflation
- Non-Gaussianity in a Matter Bounce
- Phenomenology of D-Brane Inflation with General Speed of Sound
- A Note on Calm Excited States of Inflation
- Large Non-Gaussianity Implication for Curvaton Scenario
- Curvature perturbations from ekpyrotic collapse with multiple fields
- Gravitational Wave Constraints on DBI Inflation
- Reconstructing a general inflationary action
- A new method for calculating the primordial bispectrum in the squeezed limit
- General Single Field Inflation with Large Positive Non-Gaussianity
- Generating Scale-Invariant Perturbations from Rapidly-Evolving Equation of State
- Non-Gaussianity Consistency Relation for Multi-field Inflation
- On the squeezed limit of the bispectrum in general single field inflation
- Constraints on Kinetically Modified Inflation from WMAP5
- Towards a Cosmological Dual to Inflation
- Bimetric structure formation: non-Gaussian predictions
- Cosmological constraints on general, single field inflation
- Non-Gaussianity and Gravitational Waves from Quadratic and Self-interacting Curvaton
- Superluminal motion and closed signal curves