Enhanced Non-Gaussianity from Excited Initial States

Abstract

We use the techniques of effective field theory in an expanding universe to examine the effect of choosing an excited inflationary initial state built over the Bunch-Davies state on the CMB bi-spectrum. We find that even for Hadamard states, there are unexpected enhancements in the bi-spectrum for certain configurations in momentum space due to interactions of modes in the early stages of inflation. These enhancements can be parametrically larger than the standard ones and are potentially observable in current and future data. These initial state effects have a characteristic signature in $l$-space which distinguishes them from the usual contributions, with the enhancement being most pronounced for configurations corresponding to flattened triangles for which two momenta are collinear.

33 pages, 1 figure. Refs added and minor additions

References in corpus (31)

• Wilkinson Microwave Anisotropy Probe (WMAP) Three Year Results: Implications for Cosmology
• Three Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Polarization Analysis
• Observational Signatures and Non-Gaussianities of General Single Field Inflation
• Three-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Temperature Analysis
• Three-Dimensional Gravity Revisited
• Introduction to Effective Field Theory
• Quantum Contributions to Cosmological Correlations II: Can These Corrections Become Large?
• Non-Gaussianities in two-field inflation
• On the one loop corrections to inflation and the CMB anisotropies
• Limits on f_NL parameters from WMAP 3yr data
• A numerical study of non-gaussianity in the curvaton scenario
• Roulette Inflation with Kähler Moduli and their Axions
• On the One Loop Corrections to Inflation II: The Consistency Relation
• Primordial Non-Gaussianity in Multi-Scalar Slow-Roll Inflation
• TASI Lectures on Effective Field Theories
• Primordial non-Gaussianity and the CMB bispectrum
• Large Nongaussianity from Nonlocal Inflation
• Nflation: non-gaussianity in the horizon-crossing approximation
• Seed perturbations for primordial magnetic fields from MSSM flat directions
• Primordial non-Gaussianity from two curvaton decays
• CMB quadrupole suppression: I. Initial conditions of inflationary perturbations
• Cosmological Constant and Axions in String Theory
• The renormalization of the energy-momentum tensor for an effective initial state
• Effective Field Theory Approach to Cosmological Initial Conditions: Self-Consistency Bounds and Non-Gaussianities
• Non-Gaussianity and constraints for the variance of perturbations in the curvaton model
• Axionic Inflation from Large Volume Flux Compactifications
• An effective theory of initial conditions in inflation
• Models of inflation with primordial non-Gaussianities
• Transplanckian signatures in WMAP3?
• The energy-momentum tensor for an effective initial state and the renormalization of gravity
• Non-vacuum initial states for the cosmological perturbations and the back-reaction problem of inflation

Cited by in corpus (77)

• Five-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Cosmological Interpretation
• Primordial Non-Gaussianities from Inflation Models
• Cosmological Collider Physics
• The shape of primordial non-Gaussianity and the CMB bispectrum
• Planck 2018 results. IX. Constraints on primordial non-Gaussianity
• From dS to AdS and back
• Folded Resonant Non-Gaussianity in General Single Field Inflation
• Evolution of Metric Perturbations in Quintom Bounce model
• The cosmic microwave background temperature bispectrum from scalar perturbations induced by primordial magnetic fields
• Quantum loop effects on the power spectrum and constraints on primordial black holes
• On Classification of Models of Large Local-Type Non-Gaussianity
• Large non-Gaussianities in the Effective Field Theory Approach to Single-Field Inflation: the Trispectrum
• A Note on Calm Excited States of Inflation
• Holographic Non-Gaussianity
• Galileon inflation evades the no-go for PBH formation in the single-field framework
• On Features and Nongaussianity from Inflationary Particle Production
• The Odd-Parity CMB Bispectrum
• Trans-Planckian censorship, inflation and excited initial states for perturbations
• Bootstrapping Large Graviton non-Gaussianities
• Resonant Trispectrum and a Dozen More Primordial N-point functions
• Parity-Odd and Even Trispectrum from Axion Inflation
• Nongaussianity from Particle Production During Inflation
• Symmetry Constraints in Inflation, $\alpha$-vacua, and the Three Point Function
• Large power spectrum and primordial black holes in the effective theory of inflation
• Primordial Non-Gaussianities from the Trispectra in Multiple Field Inflationary Models
• $\alpha$-vacuum and inflationary bispectrum
• Primordial Non-Gaussianity
• Cosmological Consequences of Initial State Entanglement
• Pre-inflationary primordial perturbations
• Multiple Soft Limits of Cosmological Correlation Functions
• The CMB Bispectrum, Trispectrum, non-Gaussianity, and the Cramer-Rao Bound
• Non-Gaussianities of Single Field Inflation with Non-minimal Coupling
• An optimal estimator for resonance bispectra in the CMB
• Cross-correlations as a Diagnostic Tool for Primordial Gravitational Waves
• Large fluctuations and Primordial Black Holes
• Soft limits in holographic cosmology
• On the Initial State and Consistency Relations
• Non-Gaussianities in Collider Energy Flux
• Probing the initial state of inflation: analytical structure of cosmological correlators
• Probing a stationary non-Gaussian background of stochastic gravitational waves with pulsar timing arrays
• There and Back Again: Mapping and Factorising Cosmological Observables
• Minimal cut-off vacuum state constraints from CMB bispectrum statistics
• Non-Gaussianity from Lifshitz Scalar
• Testing Split Supersymmetry with Inflation
• The scalar bi-spectrum during preheating in single field inflationary models
• Production of non-gaussianities in a bouncing phase
• Where does Cosmological Perturbation Theory Break Down?
• Cosmological cutting rules for Bogoliubov initial states
• An analytic approach to perturbations from an initially anisotropic universe
• Probing parity-odd bispectra with anisotropies of GW $V$ modes
• Scale-dependent hemispherical asymmetry from general initial state during inflation
• Vacua and correlators in hyperbolic de Sitter space
• Primordial tensor bispectra in $\mu$-CMB cross-correlations
• Trans-Planckian enhancements of the primordial non-Gaussianities
• Non-Gaussian Shape Discrimination with Spectroscopic Galaxy Surveys
• Impact of the 1/f noise and the asymmetric beam on non-Gaussianity searches with Planck
• A Flat Space Analogue for the Quantum Origin of Structure
• Non-Gaussianity from Entanglement During Inflation
• Non-Gaussianities in the Extended EFT of Inflation
• Impact of Instrumental Systematics on the CMB Bispectrum
• Model-Independent Signatures of New Physics in non-Gaussianity
• Looking for non-Gaussianity in all the right places: A new basis for non-separable bispectra
• Principal Components of CMB non-Gaussianity
• Hitchhiker's Guide to the Swampland: The Cosmologist's Handbook to the string-theoretical Swampland Programme
• Gravitational waves in a cyclic Universe: resilience through cycles and vacuum state
• Impact of trans-Planckian quantum noise on the Primordial Gravitational Wave spectrum
• CMB statistical anisotropies of classical and quantum origins
• Cosmological consequences of statistical inhomogeneity
• Constraints on the Sharpness of the Curvature Power Spectrum
• Effective Field Theory for Inflation
• Scalar parity-odd trispectrum from gravitational Chern-Simons interaction vertices
• Stochastic gravitational wave background anisotropies from inflation with non-Bunch-Davies states
• Searching for Unparticles with the Cosmic Microwave Background
• Non-Gaussian Signatures of a Thermal Big Bang
• Analytical Computation of Cosmological Correlators from Symmetries and Singularities
• Integrated Markov Chain Monte Carlo (MCMC) analysis of primordial non-Gaussianity (f_NL) in the recent CMB data
• Primordial magnetic non-Gaussianity with generic vacua and detection prospects in CMB spectral distortions